Atoi. H u m . Genet., Lond. (l979), 43, 37
37
Prortr 11 i n Great BriluirL
Genetical studies of the palmar and sole patterns and some derrnatoglyphic measurements in twins Department of
BY DANUTA LOESCH Human Genetics, Psychoneurological Institute, Warsaw INTRODUCTION
The problem of quantitative genetical analysis based on twins has not yet been satisfactorily solvr~l,particularly in respect of the inaccuracy of estimates of the genetic parameters, such as genetic variance and heritability, due to bias related to the special nature of the twin material. One of the possible sources of such a bias is the inequality of the total variances in MZ and DZ twins, as the estimate of genetic variance is usually based on a comparison of variance components in these two types of twins. The inequality of total variances indicates that the environmental variance component is different for different types of twins. That is, that there are different SOLII’CCS of variability of a given trait in monozygous (MZ) and dizygous (DZ)twins (Kenipthorne & Osborne, 1961). The inequality of total variances, although ignored in a great number of the twin studies so far undertaken, does not seem uncommon, as indicated by Christian, Kang & Xorton (1974, 1977). It has also been demonstrated for a number of dermatoglyphic features by Reed et al. (1975). Also the means as well as variances should always be compared for all characters, if the estimates of genetic parameters for these characters are to be based on the analysis of MZ and Di! twins. If there is a difference in the means between the two types of twins, this is evidence of a direct association of the value of a given trait with twinning, and the use of the lclZ and DZ twins for the estimation of genetic parameters of a given character would clearly be of doubtful validity. I n the present study the within and between pair mean squares and the means have been estimated and compared in the MZ and DZ twins in respect of all finger, palmar and sole loops and triradii, ridge counts and some other dermatoglyphic measurements. Moreover, some crude estimates of genetic variance for all the respective characters based on the two types of twins, as well as on MZ twins alone, are compared with one another, and also considered in relation to the differences in means or variances between the f wo types of twins. These estimates have been obtaiiicd for male and female pairs separately and combined.
MATERIAL AND METHODS OB DERMATOGLYI’HIC ANALYSIS
‘The material for the present study consists of palm, sole and finger prints from 221 pairs of like-sexed twins, 1 1 0 monozygous and 11 1 dizygous, collected in schools in the city of Wroctaw. There are 60 male and 50 female MZ twin pairs and 62 male and 4 9 female DZ twin pairs. The initial zygosity determination was based on testing blood groups: ABO, MN, R h (tests with anti-C, -c, anti-D and anti-E, -e) and other genetic markers (Hp, Gc, Gma). I n addition, 7 4 twin pairs were tested for Gm (b, f, 1, 2)) PGM, GPT, AK, Inv, 6PGD and ACP.* I n the rare
* All these tests were performed by Dr Danuta Schlesinger at the Institute of Experimental Therapy and Immunology, Polish Academy of Sciences, Wroclaw. 0003-4800/79/0000-4306 $03.00 @ 1979 University Colloge London
38
rates i i i liith zygosity coi~ltlnot be tlt~terininedon the basis of genetic markers, a polysymptomatit. t t s t of himilnrity \\as r i s x l rtctording to the method of T-ersehuer (1928) a n d Siemens (1937) n hiell intlud I series of morpholo~icalcliaracteristics of the skull and the face as well as basic blood group s ms, and a probability was estimated according to the method introduced by 11yslouchou a K- Or.cz?-kon-ska-Sniqtkon-ska (1969). Dermatoglyphic p t terns on soles, palms and finger-tips hare been classified by the topological method of Penrose K- Loesch (1969, 1970) and Loesch (1975),respectively. Schematic represenlogically significant pattern elements of palms, soles and finger-tips included in are presented in Fig. 1. Loops and triradii have been considered separately but various combinations of intercorrelated 01 tincorrelated pattern elements have also been used as single clmracter5 in the analysis I n orcler. to use t h e apparentl>-qualitatire characters for the purpose of quantitative analysis, they vere expressed in the form of pattern intensities; that is to say, the number of loops or triradii of any one particular type on both left and right palms or left and right soles of each persoil or on the two homologous finger-tips was counted, and this scored from 0 to approximately 4. _4lte1*nati~-ely, for each specified area, or for all the areas of palms or soles, the numbers of loops of appropriate types viere added toget her t o form respectively pattern intensities for each area and tlie overall pattern intensities. Iii order to obtain the mean values, the total number of loops of any kind was dirided by the number of individuals in the sample; the quotient is equii-alent t o the frequency per person (or per pair of hands).
Palmar and sole patterns in twins
39
Dermatoglyphic measurements included : (1) finger ridge counts on individual fingers and the total ridge count ; (2) palmar a-b count and (relative) distances between a-b, b-c and c-d palmar triradii (i.e. each distance divided by the total a-d distance) ; (3) minutiae count in the form of the E and I indices which represent respectively the relative numbers of ends and the intensity of minutiae, the intensity of minutiae being equivalent to the number of ends and junctions divided by the number of ridges in the palmar area below the triradius d , left and right combined. (For the explanation of this procedure, see Loesch, 1973) ; (4)‘ e ’ and ‘f’hallucal ridge counts.
The ridge counts have been performed according to the recommendations of the 1967 London Conference on Dermatoglyphic Nomenclature (Penrose, 1968). The statistical significance of differences between the mean values and frequencies in MZ and DZ twins has been evaluated by comparing them with the corresponding standard errors, by using- the formula: u=
2, - x2
JE.2)’
where 5, and if2 are the mean values of a given trait in MZ and DZ twins, St and S2, are the variances, and n, and n2 the number of MZ and DZ twin pairs. ANALYSIS OF VARIANCE
The within ( W )and between (B)pair mean squares were computed for all characters according to the standard procedure. Following the suggestions made by Christian et al. (1974), for reasons they explain, the total variances were then compared between MZ and DZ twins by means of a two-tailed F test: (BDZ+
wDZ)/(BMZ+
%Z)
Or
(BRIZf~~Z)/(BDZfWDZ))
with the larger sum of squares as the numerator; therefore, the probability would be twice that shown in usual F tables (or as presented in the Tables included here). I n the case of twins, the numerator and denominator of this fraction represent an estimate of half the population variance on the usual assumptions. The total number of degrees of freedom was calculated according to the formula: (BMZ+
w M Z ) 2 / (BGL) Z
+
(a) 9
and, analogically, for DZ twins. The between-pair mean squares ( B )in the two types of twins were also compared by means of which was a one-tailed test and the probability, PR,was given here according the ratio BhIZ/BDz, to the F tables. The WDZ/W,,, ratio was also evaluated in the same manner but it indicates the difference in respect of within-pair mean squares in DZ and MZ twins and thus, the approximate degree of genetic determination of the analysed traits; this is equivalent to Dahlberg’s estimate of heritability (Dahlberg, 1926). The degree of genetic influence may be also evaluated by the ratio : (B&JZ-
KIZ)/(BMZ+
WMZ)
nhich, i i l fact. i i equiralent to the ratio of the N Z twins' covariance t o the total rariance (Kempthorne S- Oshoriie. 19til), and n-as calculated for all characters included here. However, Ijotli the cwmmon piwiatal environment a n d competitive forces in the earlj- foetal life would bias this estimate in oppmite directions. I havt~used the method of estimating genetic variance from the mean squares recommended by Chiihtian et nl. ( I 9i1), where a within-pair estimate is equivalent to : A
G,v* = %, and a hetween-pair estimate is represented b y :
GB7. = B,,,
-
K I Z>
-
B DZ.
These differences, according to the theoretical model of the components of variance within and between pairs (Falconer, 1960) should contain solely the genetical (3 additive and $ dominant) variance. However, the interpretation of these estimates is of considerably limited accuracy as far ah it relates to the degree of genetic determination of the analysed characters, especially if the 11% itnd DZ total rariances are not equal. as was the case in a majority of traits included in the 1)resent study. In such a vase these par:tmeters are naturally biased as a result ofthe difference bet\\ren the t o t J varianccs. As has been denionstrated (see Christian et al. 1974), the withinpair ,tnd between-pair estimates are biased in opposite directions as a result of this difference. 'I'hcndoi~.the+> authors reronimentl their mean i i s a combined estimate of genetic variance, I\ hew thew. effects J i o d t l theoretically cancel, and n hich, a t the same time, is identical mith P~il(~on~ hrfitn ~ * .cwi-t\r h in ])airs component of genetic x-ariance (Falconer, 1 O t i O ) : A
6, 'l'=
(GI,,
h
iG , rr)/2.
-4i t l i r ,ilJwlnte \ ;ilucs of this parametcr cleprncl, to some extent, on the order of magnituclc of tlirl Ialuc of a given trait and thus. cannot be directly compared between the chamcaters in of the amount of genetic compoiicnt . their significance level is also indicated in the Tdblcx+.I t 1~ Iwen tc-ted by the ratio : (BMZ
+ J G z ) / ( ~ L )+z J G Z ) >
it11 thtl appi oxirn,itc*degrees of freedoin calculated as explained earlier for comparing the total \-ariances. This ratio is judged bv a one-tailed F test on the assumption that if genetic variance i:, prescnt, the expected value of the nuinerator is greater than that of the denominator (('hristian et ((1. 1974). Jnccluality of cov-ariances in N Z and 1)Z twins, which cannot be excluded, niay also bias this (or a n y ) estimate of genetic \ ariance. Therefore, considering the inaccuracy of the estimates, all the genetic parameters obtained in this study are mainly used only for making an approximate (+omprison of the degree of genetic determination of dermatoglyphic pattern elements and their (*ombinationssuch as pattern intensities, instead of attempting to estimate the precise proportion of the genetic rariaricc in the total variance for each character. \\
RESULTS A S 1 ) COJZMENTS
Thr. rwults for finger pattern intensities, finger and palmar ridge counts and some of the 1)dm.ti and sole measurements are presented in Table 1, a - for sexes combined, b - for males, aiitl for females. The data on palmar and sole pattern elements are given in Table 2 , r( - for w\;e\ conibinetl. b -- for inales. and c - for females. i.
Pulmar and sole patterns in twins
41
XZ-DZ differences between the means and the variances It is clear that the mean values or frequencies in MZ and DZ twin samples are llot appreciably different in the vast majority of pattern elements and measurements included in this stndy. This indicates that the values of these traits are not appreciably influenced by the type of twinning, a result which may be partly attributed to a considerable degree of genetical determination of most dermatoglyphic features. The fact that, in the present material, the observed differences between means are confined to the traits in which the non-genetical component appears predominant, such as minutiae counts and the ridge count on the Vth fingers, can be some indication of this. Unlike the situation with means, unequal total variances in MZ and DZ twins are not uncommon. It is particularly evident for finger pattern intensities and ridge counts and €or the thenar and overall palmar pattern intensity. At the same time, there is no convincing evidence for the inequality of between-pair mean squares for these traits except for pattern intensity on the thumb. This indicates that the difference in total variances may be largely attributed t o differences in the within-pair mean squares, related t o a considerable degree of genetic determination of these traits. It should be observed that, a t the same time, all genetic parameters for these traits are relatively high. However, if there is strong indication for the inequality of both the total and between-pair mean squares, such as, for instance, in a case of the z’’ sole triradius in males or the palmar anti sole loop I1 in females, it may be assumed that these differences are related to different environmental influences in both types of twins. Indeed, all the genetic parameters for these characters arc relatively low. The situation is apparently different in a majority of sole patterns, some palmar patterns and the sum of distal loops, where the between-pair mean squares are clearly unequal, while there is no convincing evidence for the inequality of total variances. At the same time, most of these characters have relatively high genetic parameters according to the present data. The reason for such an inconsistency may be that MZ-DZ differences in respect of within-pair mean squares and between-pair mean squares balance each other and the inequality of environmental influences in two types of twins is not detectable by comparing the total variances. At the same time, however, such a phenomenon may be evidence that the MZ-DZ differences in respect of the within-pair similarity are, for such traits, increased by non-genetic influences such as a common prenatal environment in MZ twins. This would naturally increase the estimates of genetic parameters as obtained directly from the mean squares. It is also evident from the Tables that the differences between MZ and DZ total and betweenpair mean squares are, for a large number of characters under this study, not consistent in the two sexes as regards magnitude and direction, which makes the interpretation of these differences as well as the estimated genetic parameters based on twins even more elusive. Genetic parameters At the same time, the approximate estimates of genetic parameters, such as the within-pair variance ratio, MZ covariance/variance ratio and 6,, genetic variance, obtained in this study are, except for some palmar loops, consistent in both sexes. Although for the reasons discussed earlier in this paragraph, these estimates should be considered with caution, they indicate
+
distance
a-b count Minutiae ( E ) Minutiae (I) Soles e count f count
c- d
IV V Total Palms a-b distance b-c distance
I1 I11
I
Ridge coillit
'I'otnl ( / ' I f f ' )
=milid
C",
(IV+ V)
( I 11) (I+II+ITI) (111+ I V + V)
v
IV
JII
I I1
l " l ~ t l ~ t ~ 1Ill(l.ll~lty 1
1~'lIlgyr~
Cll;ll~'ll~t ('1's
0.008 0.025
1.419 428-366 1.871 683.133
18-25 2.001 13.90 47-48 2.538 52'77
0.002
1.387 7.206 14.561 I I 769 5'039 4'25 I 3.862 7.912
2'010
2.172
2.81I
2.090
(4
I 8.901 11.514 5'514 9.063 7'523 8.604
10.81I
2.378 1'333
2.505
3'009 4.018
( Jf')
I+t wt V ~ l l W i t I iiri ptiirs pirs
9'393 9'407
I 2.690
6.071
12.588
3'537 4'777 2.882 3 '447 1.213 11.833 19'922
MZ
5.099 0.01 0.06 6.829 0'01 0'10 4.677 0.00 0.48 4.388 0.09 0.10 2.720 0.00 0.98 18.017 0'01 0.05 33.462 0'00 0'20 23.283 0.00 0.69 10.553 0'00 0.55 13'314 0'73 0'00 I 1.385 0.17 0.35 16.516 0'00 0'34 1
0.008
53.537 96.491
0.023
18.441
0'001
0.001
0.001
221.471 385.106
0.018
99.655 0.007
0.002
0.005
0'002
0.00~
0.003
0.003 0.006
501.065 880.061
118.456 216.236 0.016 0.015 0.048 0.041
0.003
0.003
279.594 481.903 494.955 779.624
0.023
0.008
116.581
0.001
0.001
0.001
7,274
1.000
8,691
7.011
8.066 5.105
0.00 0.00
0.44
0.04
0.28
0.53 0.49
5.130
5.222
1.000
1.000
6.322
1'000
1.00 1.000
0.99
0.81
0.64 0.24
0.00
0.68
0.00
0.00
47.100 260.100 342.617 508.599 602.717 0.29 0.00 53.468 3 2 I .560 43 I '284 476.528 752.844 0.00 0.08 48.291 26 I '443 250.869 356'538 512.312 0.02 0.19 43'702 306.092 306.401 395'595 612.493 0.01 0.23 I 3.068 140.592 I 13'577 I 50.872 254.169 0.00 0.54
0.836
5'21 I
0.69 I 0.873 0'291 I ,964 2.800 1.891 1.164 5'032
1'200
0.727
100.015
0.002
0'001
0'005
0.013
461.499 423.060 308.247 351.893 137.804 2095'I54
0.007 0.004 0.952 0.008
1.538 1.710 1.542 1.668 1.131 3.692
2.810 3'577 2.191 2'574 0.922 9.869 17.122 10.697 4'907 7.658 4'152 8.571
0.39 0.003 0.37 0.26 0.004 0.29 0.36 0.004 0.34 83.57 0.958 83.28 0.82 0.008 0.84 0.75 0.015 0.67
47.91 36.60 32.52 47.48 30.07 147'75
0.1 60 5.69 0.138 0'1 81 5.69 0.160 0.142 4.84 0.141 6.09 0.135 0.154 0.092 4.69 0'1 I 2 0.301 11'37 0.256 0.396 16.21 0.364 0'313 I 5.61 0.327 0'21 2 10.78 0'214 0.265 4.04 0.197 4.21 0,187 0'195 0.280 13'49 0.268
45'34 2.058 32.80 1,979 31.76 1.682 45.38 1.805 28.67 1.124 145'45 4.384
5.36 444 5.91 4.36 10.80 I 5.64 15.11 I 0.27 4'04 3'93 I 2.96
5 '44
(It')
p i i x
\Vit I I i 1 1
Table 1 a .
216.476 348.246
0.78 0.75
0.001
0.004
49,250
0'000
-0.002
0.69 -0.04 0.04
0.31
0.20 0.28
0.81 0.78 0.72 0.78 0.83
0.82
-0.12
0'21
0.67 0.72 0.70 0.62
0.52
0.49
-0.001
I
0.50
0'52
I
0.59
'50 r ,792 0.917 "034 0.289
,
+
t j
radial
uinar
0.40 0.26 0.35 83.06 0.77 0.75
42.37
Palms a-b distance b-c distance c-d distance a-b count Miriutiac (E') Minutiae (I)
Soles e count f count
Iv
V Total
16.12 15-48 10.48 5'29 4'33 13'29
11'12
6.10 4.38
5'00
5.60 5'52
iv
49'22 33.70 33.36 48.20 31.10 153.03
I I1 I11
Ridge count
Total ( P I F )
C
'
+ + +
I I1 I11 IV V (I 11) (I I1+ 111) (111s.I V +V) (IV V)
Fingers Pattern intensity
Characters
4.04 4'3 1 13.86
11.15
4'97 6.19 4'95 11.61 16.58 16.1 I
5.82
5'79
@ L
7
5.662 48.57
2'357 0.936 8.670 15.370 9'550 4'550 7'702 3'549 7'552
2'200
3.001 2.950
1.305
2.086
0.017
458.498 624.609
0'002
73.084 0.006 0.030
0.005 0'012
0'002
Mean squares
0.001
0.001
0.001
0.001
0.002
336.290 449'395 290.064 284.105 130.258 1116.983
2.419 4'032 2.968 2.581 1.839 9'548 I 8.452 13'774 6.742 10.960 7.968 8.952
(W)
0.004
259'525 308.066 263.497 344'397 141.570 1450.885
I '773 2.092 1.562 5'592 I I '340 I 1778 5.608 3.801 3.874 7.181
2.114
1'875
(a
Between WitEiiii pairs pairs
r__h_7
DZ
-
0'00
0.002
0.002
0.005
0.003
240.886 0.018 0.016 0.057 0.038
0.003 0.003 91.892
0.03
0.55 0.03
0.00
0.32
0.01
262.209 529.903 503.147 0.79 502.258 708.591 767.760 0.72
0'021
0.017 0.027
71.405 240.938 83.982 265.502
0.008 0.008
0'012
0.06
0.58 0.79 0.79
0.05
0'00 0.01
0'20
0.32 0.97
0'01
0.10
0.03
P,
0.04
0.40 0.04
PT
r-----h7
4'032 3.456 4'450 3'521 6.130 6993 8.263 6.775 6.527
1.000
9,182 8.180 6.157 7.094 8.791 5.998
0.00
0.01
3.672 5.981
1.056 0'457 5'530 10.124 4'757 2.325 4.893 1.567 4.358
0'20
0.73 0.76
204.182 388.691
43.767 0.003 0.003
0'000
-0.001
0'000
292'575 234.616 160633 112'353 49'343 0.81 614.705 0.87 0'75 0.76 0.78 0.78
0.99 1.000 0.31 0.17 1.000 0.33 0.91 7.288 0.59 0.90 0.667 -0.33 0.04 0.02 0.778
0.11
0.16 0.59 0.69 0.23
0.20
0'00
- 0'1 2 0.85
0'20
0.69 0'75 0.65 0.63
0.5 I
0.67 0'43 0.53 0'52
Within MZ pair cov/ variance var ratio ratio
7
12.350 0'00 14.761 0.45 0.00 2.160 I I .842 0.04 0.63 I .768 16.133 0.00 0.42 i'4'724
25'552
4'294 6.146 4.741 4.673 3.401 15.140 29'792
DZ
difference
581.635 595.815 0.93 437.785 757.461 0.01 388.915 553.561 0.10 365.100 628.502 0.01 139.631 271.828 0.00 1935.746 2567.868 0.19
3.601 4.117 2.867 3.090 1.236 10,237 I I .603 11.583 5.583 12.777 8.057 8.160
MZ
Total (2')
MZ-DZ
level of
I+
w
s*
2
9
&?
g r
s
_L__-____ Significance Genetic parameters
18.808 103.813 137.072
0.001
0.001 0.001
0'001
0.006 0.009
36.625 54'941 47.108 40.05 I 14.817 186.217
0.600 1.167 0.667 0.733 0.300 1.567 2'233 2'033 1.033 5'075 4.508 0.608
Between Within pairs pairs (B) (W')
7 -
MZ
2.062 545.010 2'247 382.844 2.078 341.807 2.376 325.049 1.523 I 24.814 4.877 1749.529
0'175 0.186 0.171 0.185 0.160 0.302 0.43 1 0.439 0.303 0.250 0'252 0.343
S.E.
4
7
DZ
49.19 37'52 33.40 49.70 32.84 152'34
A
0.35 0,004 0.33 0.006 0.006 0.32 1.113 81.67 0'010 0.85 0.023 0.64
3'039 2.569 2,407 2.367 1.454 5'445
0.402 0.278 0.361 0.245 0.358
0.510
0.179 0.224 0'193 0.176 0.126 0.383
S.E.
MZ
7
Means
7 -
(Moans ( B )standard , errors (s.E.) and mean squares ( B ,TY,T ) ,significnnce l w d of MZ-DZ differences in respect of total ( P T )and betwern h ( P B )mean squares, within-pair DZ/MZ variance ratio (P),MZ covar.isiree/variance ratio and G,, genetic variance for pattern intensities and som0 finger, palmar and sole dermatoglyphic measurements (left and riglit combined) in a sample of 60 MZ and 62 DZ male twin pairs.)
Table 1b.
f count
SOlc?S e count
Total Palms a-b distance b-c distance c-d distance a-6 count Minutiae ( E ) Minutiae (I)
V
IV
I1 111
I
Total ( P I P ) Ridge count
=radial
="I,
+
+
V (I 11) (I+ I1 + 111) (111+ IV + 1 7 ) (IV V)
117
I I1 I11
Fingers Pattern intensity
Characters
0.208
0.226 0.295
2.561 3.092 2.309 2'722 1.677 6.937
13.55 53.31
2.681 3.742
r-L-7
MZ ( P A - - ,
5'55 5'5 I 4.67 5.96 4'35 I I .06 15'74 14.98 10.31 4'03 4.08 13.02
2'329 3.638 2.628 I ,876 0.961 9.078 18.236 I I '040 3'927 4.821 3.810 8.449
87.008 0.005
0.016
18.000
0.004
0.018
131.647 0.005
0.019
0.010
0.018
32.810 193'771 110.750 485.849
0.001
0.001
0.001
352'301 686.077
0'001
0.001
0.001
0.001
0'001
0.001
0.006 0.005 1.346
59.670 256.070 51'730 336.182 49.710 256.601 48.010 243.505 10.970 117'418 83.590 1501.316
1'110
2.440 3.480 I '720 1.320 4.980 6.120
0.280
0.880 I 240 0.720 I ,040
0.005
12.59 2.009 3.181
58.02
0.40 0.24 0.37 85.31 0.84 0.71
7.280 4.468 9'493
5'220
2'738 0.904 I I '044 18.616 I 1'704
2'1 I 0
2'502 4268
321.364 468'430 261.184 2'252 363.101 1.564 137.783 5.593 2358.090
2.310 2.646 2.312
0.420
0.282
0.275 0.234 0.198 0.141 0.435 0.616 0.480 0.286 0.3 I 7
0'220
301.591 485.714
90.653 0.008 0.026
0.001
0.002
0.001
350.622 408.367 201'275 334.612 92.469 1529.255
0.694 I 2.408 19.469 8.653 3'959 6.663 6.959 8.163
2'123
3'755 4.000 1.918
(W)
Within pairs
DZ
3.382 5.508 2.830 3.778 1.184 13.484 22.096 13'424 6.540 I 2.260 10.588 10.603
MZ
0.002
0.05 0.14 0.09 0.15 0.16 0.39
0.40 0.75 0'93 0.06
0.10
0'02
0.14 0.03 0.79 0.13 0.04
0.01
4.267 3.226 2.664 2041 2'479
0.13 0.48 0808 0.29 0.06
0.22
0'29 0.34
0.08
5.876 7.894 4.049 6.970 8.429 18.295
1.338 1.137 7'354
0 . ~ 5 5.085 0.47 5'595 0.42 5.031 0.16 2'999
0.58
0.10
0.40 0.29 0.78
o.002
385.111 495.362 0.30 796.827 971.563 0.40
0.002
0-12
0.02
9.192 4.386
G,,
0.000
0.83 0'72
0.03
213.656 287.596
0.006
0.003
58.646
0.22
0.76 0.16
0'000
0.23 0.16
0'000
78.075 203,099 0.85 50.932 0.93 1151.2rg
0.68 0.77
178.123 0.80 244'44.3 0.69
var ratio
COV/
MZ
parameters
-
Significance Genetic level of ( - - . A - ~ MZ-DZ Within difference pair c--~-,variance PT PB ratio
0.40 0'73 1.000 0.04 0.76 2.000 0'002 0'002 0.95 0.15 1.000 149.647 177.661 0.47 0.08 5.036 0.009 0.013 0.04 0.41 2.000 0.042 0.61 0.23 1.444 0,037
0.002
606.692 744'549 457.876 578.117 209.887 3030.571
6.084 7.638 4.546 3'999 1.655 21.486 37'705 19.693 7.886 I I -484 10.415 16.612
DZ
Total (T)
381.034 520.160 310.894 411'202 148.753 2441.680
Mean squares
Bctween Within Between = A 7 pairs pairs pairs A!f S.E. (B) (W ) (B)
DZ
46.28 35.43 31.40 44.67 26.57 141.95
0.39 0.004 0.26 0.005 0.36 0.005 84.18 1.639 0.86 0.010 0.76 0.020
40.67 31.73 29.83 42.05 25'75 136.35
0.236 0.136 0.475 0.616 0.489 10'02 0.326 4'52 0.385 3.46 0.302 12.55 0.440
5'24 5-18 4.64 5.68 4'34 10.42 I 5.06 14.66
%=
MZ
r - A - - 7
Means
7 -
(Means (%), standard errors ( s . E . ) and mean squares (B, W , T), significance level o f MZ-DZ differences in respect o f total ( P T )and between ( F B )mean squares, within-pair DZ/MZ variance ratio ( F ) ,MZ covariance/variance ratio and ,& , genetic variance for pattern interisit,ies and some finger, palrnar arid sole derniat,oglypliic ineasureinent,s (left and riglit combined) ill a sample of 50 MZ and 49 DZ female t,win pairs.)
Table l c . cp cp
Palmar and sole patterns in twirLd
45
(see Table 1 ) that, on finger-tips, both pattern intensities and ridge counts on individual fingers (exc.ept for finger V), as well as all their combinations may be strongly genetically determined, but genetic influence is much less appreciable if the ulnar and, especially, radial components are summed up over all ten fingers. B s concerns some other dermatoglyphic measurements presented in Table 1 the results indicate that, while the traits such as the e and f hallucal counts and the a-b ridge count may be strongly genetically influenced, the oppositt: is true for the intertriradial palmar distances and the minutiae counts ;particularly these last two measurements, E and I,appear t o be almost entirely determined by non-genetic influences, although generally low variability of these traits renders them inconvenient for the purpose of genetical analysis. Amongst the palmar and sole loops and triradii (see Table 2) the highest values of genetic parameters apparently concern all loops on soles, except for those in the area 11, and most of sole triradii, as well as all combinations of these Ioops. On palms, if loops are considered separately, consistently high values of genetic parameters are obtained only for the hypothenar distal loop €I and the axial t triradius, but they are also high for a majority of combinations of p l m a r loops; the same is true for the combination of all distally displaced triradii, t’, t” and t ~ It. is worthy of note that, as for finger patterns and ridge counts, presented in Table 1, these parameters are relatively higher for some combinations of loops, such as hypothenar loops and the s u m of interdigital loops than for the total pattern intensity on palms. This may be evidence that several pattern elements, or some combinations of pattern elements in any specified area (or in adjoining areas) are each influenced by a specific genetic system which modifies their phenotypic expression. It may also be of interest that genetic variance is not higher for anatomically intercorrelated loops (in brackets) as compared with combinations of independent pattern elements. The values of genetic parameters are generally higher for most of the characters, if sexes are combined, in spite of not always consistent results in this respect in the male as compared with the female samples, which may thus be related to a considerably modifying effect of a sample size. The estimates of genetic parameters obtained in this study for palmar, sole and finger patterns are generally in agreement with the values of the concordance rate in MZ and DZ twins and with several other ‘heritability’ estimates in the same sample of twins (Loesch & $wiqtl;owska, 1977). It is realized, however that they may all be considerably biased by the fact orb already discussed or demonstrated here. Moreover, the possibility of genetical differences bet\\rern the two members of the same pair of identical twins, which would be extremely tlifficult to distinguish from the non-genetical influences by means of traditional methods such as applied here, are believed to be an additional source of bias in the results concerning genetical pammeters (Kempthorne & Osborne, 1961; Allen, 1965; Kang et al. 1977). Although most of these may be eliminated by applying more sophisticated procedures of twin analysis such as those recently introduced and based on methods of biometrical genetics (Eaves, 1973; Eaves & Eysenck, 1975), some factors such as inequality of covariances may still influence the estimates of genetic parameters based on twins. It should not, therefore, be unexpected that the results of different twin studies, even if they are bascd on similar methodologies, are often inconsistent. Some of the data obtained in this study are not in good agreement with the GcT estimates by Reed et al. (1975),which particularly concerns the thenar loops, I+P,on palms, and sole loops in the areas 11, I11 and IV. I n both
MZ
0.089
0.079 0.094 0.048
0.038 0.069 0.079 0'057 0.059 0.03 I
0.082
0.05 I
0.136 0.083
0.1 32
0.87 I + I ' + I I + 111 1'94 Pattern intensity (PIP) 3.38 t' + t" + t" 0.98 Soles I I .78 f 0.76 I1 0'20 $1 0.60 111 1.41 If1 0.30 IV 0.35 I? 0.07 ? 0.99 P+P' 1.61 P" 0.26
+ +
0'100
0.28
0.79 1.63
0.08
I .78 0.77 0.19 0.61 I .46 0.34 0.36
0.83 1'99 1'35 0.87 2.07 3'30 0.94
I '04
0'20
0.52 0.04 1'35
0.5 I3
0.062 0.066
0'032
0'177 0'223 0'105
0'102
0.688 0.973 0'249
0 105
0.024 0.069 0.068 0.049
0.05I
0.360 0'375
0'077 0.114 0.118 0'255 0'105 0.114
0'200
0 ' 1 I8 0.3 I 8 0'414 0'377 0.382 0.359 0.814 0.664
0'513 0.269
0.522
0.419 0'477 0.272 0.285 0.062
0.136 0.449 0.076
0'390 0.078 0.535 0.400 0.481 0.554 0.473 0.710 0.628 1.562 1.914 0.556
0'277 0.064 0'200
0'220
0.033 0.438 0.526
1)tlIrs
0'100
0.064 0.246 0'359
(If.)
p~lll's
0.050
0.681
0.156
0.726
0.280
0.862 1 '903 2.004 0.745
I .080
0.766
0.807
0.080 0.472 0.496 0.326 0.429 0.062 0.662 0.31 I 0.641
(11)
p irs
0.026
0.035 0.064
0.017 0.063 0.069 0.045 0'059 0.027 0.070 0.060 0.066 0.07 I 0.066 0.080 0.076 0'119 0.132 0.071
0.08 0.96 0.95 0.31
0.027 0.066 0.067 0.055 0.063 0.024 0.078 0.053 0.077 0.086 0.084
I '27
2.15
0.79
1'01
0.15
0.08 I '24
0.52
0.26
0.08 0.93 I '14
S.K.
1 V
s ,133.
-.A 7
-nf
0.347 0.523 0.329 0.3 I I 0.059 0.478 0.914 0.266
0.180
0.315 0.496
0.460 0.248 0.496 0.824 0.7 I 2 0.766 0.878 1.523 1.892 0.680
0.081
0.357 0.840 0.274 0.768 0.786 0.474 0.480 0.134 0.865 1.196 0.354
2.717 2.668 0.945
1'221
1.143 1.462
1'221
0.825
0.718 0.855 0.426 0.706 0.126 0.862 0.429 0.959
I '427 0.535
1'000
0'121
0.66
0'00
0'00
0.03 0.07 0.07 0 07 0'00
0'1 I
0.15
0'01 0'00
0'00
0.41 0.06
0.15
0.05
0'01
0'01
0.3 I 0.89 0.13 0.91 0.07 0.03
0'02
0.35 0.62
0'00
I'll
0.14 0.46 0.33 0.24
0'12 1'000
0.45 0.64 0'99
0'12
0.07
0'01
0.90 0,38 0.80 0.95 0.14 0'37
0'00
0.33
0.08
0.03 0.31 0.04 0.03 0.46
I'T
0.601 0.596
0.45 1 0.945 0.256 0.766
1.130 0.589 0.782 0'159 0.995 0.648 0.977 1.379 1.185 1.476 I ,506 3985 3.806 1.236
0.105
0'I44
DZ
0.387 0.604 0.369 0'392
MZ
0.072
( 117)
pairs
1.125
2.962 I444 2.701 4.099 2'533
2,886
4.091 4'35' 1.525 1.361 4.981
2.446 1.871 2449 3.400
2.005
1.888
1.560 1.990
2'IOI
2.300
3.690 1'415 I ,266
1.682
1.573
0.152
0'149
0.034 0.234 0.576 0.071 0.53 0.59 0.63 0.41
0.311
0.56
0.071 0.093
0.330
o.rgr
-7
0.34 0.73 0'52
0.57 0.73 0.14
0.58
0.50
0.54 0.45 0.34 0.32 0.34 0.48 0.41 0.40
0'01
0'21
0.32 0.16 0.53
0 ' 1I
var rntio
rev/
p iI' variaricc
ratio
MZ
\Vithiii
+
0.42 0.36 I -66 I .96 3'07
loops
loops
+ soles
'pmnimd
'distal
Palms
+ +
6.48 3'35
0.42 I -72
0.44 0'121
0.075 0.048 0.014 0.068 0.073 0.087 0.058 0.061 0.808 0.741 1.165 0.457 0.650 2.426 1.385 3.493 2.564
0.055
0.803 0'391
2'00
0.198 6-50 0.161 0.195 3'19 0.158
0.113
0.264 0.768
0.500
0.505
0.173 0.400 0.173 0.136 0.146 0.527 0.209
0.023
3.636
1.532
0.840 0.365 0.415 I .605 0.925 2'394 I .920
0.582
0.506
0'021
0.159 0.625 0.096 0.259
4.288 0-723 2'499 4-1-57 0.923 2'736
0.092 0.179 3-18 0.I 48 2.60 0.132 0.153 0.136 2.23 0.118 2.080 0.229 6.40 0.182 5.693
0.065 0.077 0.149
0.103
I 71
0.80 I -80
0.03 2.55
0.35
0.060 0'022
0.086 0.082
0.86
0.086
0.04 2.54 0.80
0.89 0.31
II+r^I+III+IiI* 2'5 I 2.13 (111+ If1 rv IV ) Pattern intensity (PIS) 6.48
(f + fI + 111) I1+ III+ IV (1+ fi+ I11+ 111)
(I1 I^I! (III+III) I V +I F (If1+ IV)
I+i
z"
' 2
z
Table 2a (cont.)
2.946 2.856
0.21
5.011 5.080
5.445 5'592
0.09
0.01
0.00 0.01
0.52
0'01
0.59
0.33
0.13
0.07 0.06
0'27 0.12
0'02 0'02
0.13
0'02
0'12
0.62 0.77
0.04
0'10
0.01
0.00
0.02
0'12
0.29 0.09 0.73 0.06
0.64
1.035
0.588 0.067 1'272 1.199 1.800 0'743 0.856 3'092
0'593 0.796 2.953 1.594 2'020 3'998 4745 3.064 3.875 2.344 2.978 6.461 7.514
1.338
0.962 0.487 0.078 0.981 1.142
0.30
0.67 0.61 0'42 0.65
4.075 3.094
0.71 0.64
0.74 0.54 0.63 0.64 2.822 5'239 0'73 4'6.55 0'75 3.910 0.67 5.477 0.77 5.049 0.76
2.579 3.427 1.961 4.428 1'543 5.549 2.779 3.021
(a),
+ +
+
+
z
P"
P+P'
e
1I1 I11 If1 I? IV
P
I
Sole patterns
l'+t"+t"
S.E.
+
0.045 0.089 1-19 0.094 0.083 0'35 0'43 0.078 0.13 0.041 I .28 0.099 0.23 0.094 1 . 1 3 0.109 0.78 0.118
--
-
0.092 0.086 0.050
0.103 0.130
0'10
0.83 I .78 0.36 0.98 0.118
0.074
0'100
0.049 0.093
0'1 I 2
I .80 0.80 0.19 0,64 1.57 0.41 0.47
1'01
0.86
0.28
1.78 0.77 0.19 0.61 I .46 0.34 0.36 0.08 0.79 I .63
0.141 1.35 0.I 26 0.87 0.193 2.07 0.207 3'30 0'110 0.94 0.065
0.123
I .48
0.83 1.99
0'20 I '04 0'250
0.891 1.170 0.935
0'995
0.596 0.495 0.441 0.148 0.631
0.509
0.743 0.I 42
0.252
2.526 0.712
2.192
0'101
0.820
0.326 0.098 0.150
0.217 0.529 0'250 0.491 0.142 0'303 0'175 0.622
0.444
0.903 0.218
0.081 0.436
0'290
0.321
0'125 0.050
0.323
0.091
0.447 0.438
0.092 0'275 0.067
0.540 0.218 0.355 0.460
0.331
0.457
0 ' 150
1.234
1.189 0.496
7
3.150 3.101
1.141 I .628 1.285
1.311
1.055
0.720 0.884 0.553 0.662 0'I99 0.787 0.671
0'220
MZ
0.876 0.234 0.784 0.663 0.621 0'591 0.198 0.848 I '245 0.468 0.995
0.302
PT
0'521 I .066
0.898 04344 0.616 0.179 0.965 1.394
0.802
0.481 0.997 0.309
0.57 0.74
0.5 I 0.58
0.54 0'1 5 0.91 0.16 0.87 0.83 0.59
0.03
2.ooy
2.584 1'933 I .620
6.866
6.620 4.060 2'370 1.291
2.752
2.146
I '204
3,612 0.39 1'535 0.14 2'537 0'00
0.25
0.06
0'12
0.05
0'1 2
0.04 0.3I
0.03
0'02
0.08
0'00
0'02
0'1 2
0'01
0'00
2'120
1.601 1.487 3.000 1.539 0.03 0'1 I
1'020
2.288 0.26
0.80 0.60 0.49 0.49 0.49 0.60 0.40 0.65
0.30
0'22
0.67 0.69
0.233
0.040 0.160 0.575 0.049
0.1 28
0.186
0.275
0.191 0'347 0.089 0.071
0.537 0.998 0'334
0,317
0.241
0.229 0.524 0.390
0.26 0.56 0.44 0.45 0.39 0.63 0.47
0.179 0.092
0'002
0.32
0.47 0.55
1.050
0.400 -0.01 0'00
0.05
GCT
0.041 0,093 0.19 0*182 0,46 0'193 0.09 -0.027 0.28
0.09
MZ cov/ var ratio
0.75
0'00
2'260
1.469 1.802 0.27
1.120
0'00
Within pair variance ratio
Genetic parameters
0.28
PB
Significance level of MZ-DZ difference
0.173 0'12 0.69 0'777 I *094 0.25 0.544 0.93 0.656 9'52 0.075 0'00 0.965 0-30 0.495 0.13 I .003 0.78 1.322 0.97 1.093 0.82 1.336 0.30 1.435 0.57 2.466 0.19 2.423 0'21 I .206 0.27
DZ
Total (2')
0.710 0.970
1.153
1.313
0.430 0.604 0.343 0.634 0.693
0.379 0.645 0.339 9.3I5 0.040 0.476 0.153 0.573 0.718 0.750 0.702 0'742
0.113
0.133
0.050
0.258
0.458 0.350 0.958 0.575
0.358 0.483
0.828
0.697
0.208 0'1 5 0
0.071 0.326
0.090
0.086 0.039 0.086 0.085 0.072 0.073 0.040 0'093
0.050
0.090
0'I47 0.I 40
0.I 07
0'102
0.300
0'342
0.431 0.035 0.489
0.150 0'100
0.205
0.358
0.050
0.398 0.449
0.258
0'100
0'521
0.462 0.526 0.403 0.362 0.099 0.579
0.081 0.086 0.058 0.084 0.024 0.089 0.075 0.084 0.099 0.075
0'1 20
0.029
0.96 0.95 0.3 I 0.52 0.04 1.35
r-h---,
DZ
Mean squares
Between Within Between Within pairs pairs pairs pairs S.E. (B) (W) (B) (W)
+ 7
MZ
0.08
iv
DZ
2.32
1'01
0'1 2
AT?
MZ 7
7 7
0.92 I +I'+II+111 H + A 2.14 Pattern intensity (PIP) 3.64
H+A+H'
(I 1') (I1+ 111) (H A) I1+ 111+ IV (I1+ I11 H)
t
Iv H A H'
I1 I11
Characters Palmar and sole patterns
Means
r
(Means standard errors (s.E.) and niean squares ( B ,W , T), significance level of MZ-DZ differences in respect of total ( P T )and between ( P B )mean squares, within-pair DZ/MZ variance ratio ( F ) ,&I2covariancelvnriance ratio and G,, genetic variance for topologically significant pattern elements of palms and soles and pattern intensities in a sample of 60 MZ and 62 DZ male twin pairs (left and right combined).)
Table 2 b .
W P
M
0
m
P
+
l0WB
zproxima~loops
&.td
Palms + soles
+
(If1+ IV) (f 4-I? t 111) 11+ I,II IV (1+ I1 +I11 + 111) I1 + f I + 111 + IIIA (III+ 111 + IV + IV) Patt,ern intensity (PIS)
rv+Ik
I+f (I1 11) (111+ 111)
2"
d
7.02 3 '40
3'42 2.81 2'54 6.83
2.23
1.85
0.5 I
0.43 0.06 2.60 0.83 I -98 0.57 0.35
0.293 0.276
6.50 3'19
0.867 1'100
5.050
4'490
0.173 0.223
3.718
1.331
1'742
5'9x7 5'590
4.605 6.083
0'00
0.07
0'22
0.68
0.83
0.23
0-23
0.90 0.47
2.025
4'372 3'579 3 '05 5 7'711 4'243 3.076 2.369 6.73I 2.032
0.06 0.09 0.04 0.09 0.27 0.17
0.02
0.32
0.10
3.200 2.771
0.07 0.29 0.13
0.29 0.26 0.37 0.76 0.88
1'143
4'7331 1.916 4.226 1.935 2.857 2.614 4.804 3.584 3.667 3.892 4.551
0'00
0'00
2.669 0.02
0.85
3.152 I .670
3'255
0.674 0.071 1.336 1.130 1.383 1.345 1.697 0.696 0.826 1.104 I '042
0.649 0.126 0'974
1.524 1.081
0.500
0'379 0.048 0-790 0.734 0.879 0.387
1.831 2.774 3'035 3.048
0.070 0.507 0.142 0.295 0.03 0.019 0.084 0.042 0.023 2'55 0-095 0.807 0.167 0.546 0.80 0.103 0.747 0.383 0.649 0'112 1.137 0.208 0.818 0.139 I .80 0'1I5 0.092 0.44 0.085 0.496 0.200 0'439 0.126 0.42 0.094 0.929 0.175 0.542 1'72 0.168 2-569 0.583 1.731 02og 2 '00 0.124 0.151 1.345 0'22.5 0.943 3.18 0.196 3.676 0.567 2.340 0'250 2.60 0'1 74 2.601 0.475 1.837 0'210 0.185 2.23 0.168 2'027 0'342 1.724 5.914 0.817 3'993 0.317 6.40 0.256
0.093 0.038 0.117
Table 2 b (cont.)
0.61
0.71
0.56 0.34 0.66 0.32 0.69 0.42 0.68 0.63 0.71 0.73 0.69 0.71 0.76
& &
O1
Q
.Y q
1'702
2.563
E'
3 3'
0.356 0.890 0.629 ?2 1.401 1.015 0.646 2.411
0.122
0.495
0.225
0.225
0.034 0.442
2
0'112
0.07I 0.083
1.22
0.33 0.65
I8 0.433 0.054 0.352 0.488
0'1
0.296 0.439
0.55 I '23 0.16
0'21
0'121
0'102
0.059
0'1 I
0.27
0'442 0.791
0.190
1.053
0.054 0.826
0.3 I I
0.414 0.871 0.187 0.689 I .090 0'542 0.569 0.045 I '041 I .396 0.552
1.301
0.14 4.085 0'02 4489 0.97 5'450 0'00
0'22
3.000 0'00
0'32
0'01
0.41
1'465 4.013 3'370 6.740 0'00
0'10
0.72 0.33
2.691 4478 0.887
3.109 3'539 4.946
0.48 0.77 0.06 0.38 0.66 0.24 0.68 0.63 0.68 0.64 0.37
0.71
0'22
0.64 0.35 0.38 2.841
0'01
1.251
0.40 2.921
0.33
1'474 2.906
0.09 0.78 0.34
0'00
0'01
0.05
0'00
0.23
0.92 0-69
0.05
0'52
0.34 0.71 1.641 0'1 I 0.39 1.559 0.14 0.08 3.865 0'00 0.81 5'490 0'00 0.99 I ,265 0.16 0'21
1.111
1'00
0.48
0'00
1.073 1'154 1.139 2.090 1.970 0.913
I '00
0.14 0.83
035 0.84 0.65 0.09 0'00
0.62
0'00
0.08
I', 0'00
0.997 0.836 0.926 1.438
0.258
I', 0.03
0.949 0'1 I8 0.808
0.030
0.030
0.743 0.872 0.264
0.701 0.090 0.171 0'1 50
0.095 0.033 0.086
0'1 I 0
0.313
0.050
1.990 2.725 0.643
1'05 I
1)Z
0.048 0.696 0.880 0.814 1'159 0'254 0.648 0.738 0.819
MZ
0.38 0.230 0.337 0'513 0.602 0.722 0.150 1.19 0'101 0.058 0.26 0.065 0.164 0'I 0 0 0.205 0.337 0'21 0.050 0.232 0.337 0.073 0.32 0.069 0.261 0.03 0.030 0.03 0.017 0.044 0'010 0.014 0.03 I 1.17 0.119 0.86 0.103 0.696 0'130 0.5 I 0 0.531 1.28 0.099 0.863 0.190 0.470 0.929 1'39 0.133 0.14 0.052 0.29 0.068 0.130 0.060 0.225 0.327
I .83 0.66
1'200
0.783
I
0.408 0.490 0.1 33 0.439 0.367 0.398 0'9.59 0.663 0.847
0.551
0.398
0'020
(It')
J)tlil.R
0.321
0'120
0.080
0'1 25
0.190 0.558 0.080 0.469 0.270 0.528 0.330 0'479 0'530 0.638 0.290 0.794 0.370 0.508 0.640 1.875 0'770 2.765 0.130 0.623
0.250
0.488
0'759 0.038 0.538 0.781 0.543 0.864 0.769 1 '450
0.360 0.040 0'020
0'230
0.466 0'454 0.214
0.028 0.482 0.608 0.240 0.329
(J4
Iniw
0'010
0'020
(It')
p 1 II's
0'010
(14
1 I i L I 1's
0'133
1'75 0.71
0'02
0.014 0.15 0.05I 0.108 I '09 1.19 0.124 0.04 0.028 0.27 0.099 0.87 0.105 0.87 0.105 0'79 0.126 0.98 0'100 1'99 0'1 I 5 1'95 0'105 I '03 1.19 0.129 0'133 0.81 1.13 0'I 03 0.1 25 I '70 0.172 2.13 0.198 3'07 0.156 3.64 0.240 0.95 0.126 I '07 0.114
0'I 0 0
0'I00
0.85
0.83 I .08 0.16 0-63
0.014
.
0'02
h .l',
7
0.024 0.098 0.096 0.066
,
0.04
r--
rl I
-
s.1.:.
i
A1
37
Prortr 11 i n Great BriluirL
Genetical studies of the palmar and sole patterns and some derrnatoglyphic measurements in twins Department of
BY DANUTA LOESCH Human Genetics, Psychoneurological Institute, Warsaw INTRODUCTION
The problem of quantitative genetical analysis based on twins has not yet been satisfactorily solvr~l,particularly in respect of the inaccuracy of estimates of the genetic parameters, such as genetic variance and heritability, due to bias related to the special nature of the twin material. One of the possible sources of such a bias is the inequality of the total variances in MZ and DZ twins, as the estimate of genetic variance is usually based on a comparison of variance components in these two types of twins. The inequality of total variances indicates that the environmental variance component is different for different types of twins. That is, that there are different SOLII’CCS of variability of a given trait in monozygous (MZ) and dizygous (DZ)twins (Kenipthorne & Osborne, 1961). The inequality of total variances, although ignored in a great number of the twin studies so far undertaken, does not seem uncommon, as indicated by Christian, Kang & Xorton (1974, 1977). It has also been demonstrated for a number of dermatoglyphic features by Reed et al. (1975). Also the means as well as variances should always be compared for all characters, if the estimates of genetic parameters for these characters are to be based on the analysis of MZ and Di! twins. If there is a difference in the means between the two types of twins, this is evidence of a direct association of the value of a given trait with twinning, and the use of the lclZ and DZ twins for the estimation of genetic parameters of a given character would clearly be of doubtful validity. I n the present study the within and between pair mean squares and the means have been estimated and compared in the MZ and DZ twins in respect of all finger, palmar and sole loops and triradii, ridge counts and some other dermatoglyphic measurements. Moreover, some crude estimates of genetic variance for all the respective characters based on the two types of twins, as well as on MZ twins alone, are compared with one another, and also considered in relation to the differences in means or variances between the f wo types of twins. These estimates have been obtaiiicd for male and female pairs separately and combined.
MATERIAL AND METHODS OB DERMATOGLYI’HIC ANALYSIS
‘The material for the present study consists of palm, sole and finger prints from 221 pairs of like-sexed twins, 1 1 0 monozygous and 11 1 dizygous, collected in schools in the city of Wroctaw. There are 60 male and 50 female MZ twin pairs and 62 male and 4 9 female DZ twin pairs. The initial zygosity determination was based on testing blood groups: ABO, MN, R h (tests with anti-C, -c, anti-D and anti-E, -e) and other genetic markers (Hp, Gc, Gma). I n addition, 7 4 twin pairs were tested for Gm (b, f, 1, 2)) PGM, GPT, AK, Inv, 6PGD and ACP.* I n the rare
* All these tests were performed by Dr Danuta Schlesinger at the Institute of Experimental Therapy and Immunology, Polish Academy of Sciences, Wroclaw. 0003-4800/79/0000-4306 $03.00 @ 1979 University Colloge London
38
rates i i i liith zygosity coi~ltlnot be tlt~terininedon the basis of genetic markers, a polysymptomatit. t t s t of himilnrity \\as r i s x l rtctording to the method of T-ersehuer (1928) a n d Siemens (1937) n hiell intlud I series of morpholo~icalcliaracteristics of the skull and the face as well as basic blood group s ms, and a probability was estimated according to the method introduced by 11yslouchou a K- Or.cz?-kon-ska-Sniqtkon-ska (1969). Dermatoglyphic p t terns on soles, palms and finger-tips hare been classified by the topological method of Penrose K- Loesch (1969, 1970) and Loesch (1975),respectively. Schematic represenlogically significant pattern elements of palms, soles and finger-tips included in are presented in Fig. 1. Loops and triradii have been considered separately but various combinations of intercorrelated 01 tincorrelated pattern elements have also been used as single clmracter5 in the analysis I n orcler. to use t h e apparentl>-qualitatire characters for the purpose of quantitative analysis, they vere expressed in the form of pattern intensities; that is to say, the number of loops or triradii of any one particular type on both left and right palms or left and right soles of each persoil or on the two homologous finger-tips was counted, and this scored from 0 to approximately 4. _4lte1*nati~-ely, for each specified area, or for all the areas of palms or soles, the numbers of loops of appropriate types viere added toget her t o form respectively pattern intensities for each area and tlie overall pattern intensities. Iii order to obtain the mean values, the total number of loops of any kind was dirided by the number of individuals in the sample; the quotient is equii-alent t o the frequency per person (or per pair of hands).
Palmar and sole patterns in twins
39
Dermatoglyphic measurements included : (1) finger ridge counts on individual fingers and the total ridge count ; (2) palmar a-b count and (relative) distances between a-b, b-c and c-d palmar triradii (i.e. each distance divided by the total a-d distance) ; (3) minutiae count in the form of the E and I indices which represent respectively the relative numbers of ends and the intensity of minutiae, the intensity of minutiae being equivalent to the number of ends and junctions divided by the number of ridges in the palmar area below the triradius d , left and right combined. (For the explanation of this procedure, see Loesch, 1973) ; (4)‘ e ’ and ‘f’hallucal ridge counts.
The ridge counts have been performed according to the recommendations of the 1967 London Conference on Dermatoglyphic Nomenclature (Penrose, 1968). The statistical significance of differences between the mean values and frequencies in MZ and DZ twins has been evaluated by comparing them with the corresponding standard errors, by using- the formula: u=
2, - x2
JE.2)’
where 5, and if2 are the mean values of a given trait in MZ and DZ twins, St and S2, are the variances, and n, and n2 the number of MZ and DZ twin pairs. ANALYSIS OF VARIANCE
The within ( W )and between (B)pair mean squares were computed for all characters according to the standard procedure. Following the suggestions made by Christian et al. (1974), for reasons they explain, the total variances were then compared between MZ and DZ twins by means of a two-tailed F test: (BDZ+
wDZ)/(BMZ+
%Z)
Or
(BRIZf~~Z)/(BDZfWDZ))
with the larger sum of squares as the numerator; therefore, the probability would be twice that shown in usual F tables (or as presented in the Tables included here). I n the case of twins, the numerator and denominator of this fraction represent an estimate of half the population variance on the usual assumptions. The total number of degrees of freedom was calculated according to the formula: (BMZ+
w M Z ) 2 / (BGL) Z
+
(a) 9
and, analogically, for DZ twins. The between-pair mean squares ( B )in the two types of twins were also compared by means of which was a one-tailed test and the probability, PR,was given here according the ratio BhIZ/BDz, to the F tables. The WDZ/W,,, ratio was also evaluated in the same manner but it indicates the difference in respect of within-pair mean squares in DZ and MZ twins and thus, the approximate degree of genetic determination of the analysed traits; this is equivalent to Dahlberg’s estimate of heritability (Dahlberg, 1926). The degree of genetic influence may be also evaluated by the ratio : (B&JZ-
KIZ)/(BMZ+
WMZ)
nhich, i i l fact. i i equiralent to the ratio of the N Z twins' covariance t o the total rariance (Kempthorne S- Oshoriie. 19til), and n-as calculated for all characters included here. However, Ijotli the cwmmon piwiatal environment a n d competitive forces in the earlj- foetal life would bias this estimate in oppmite directions. I havt~used the method of estimating genetic variance from the mean squares recommended by Chiihtian et nl. ( I 9i1), where a within-pair estimate is equivalent to : A
G,v* = %, and a hetween-pair estimate is represented b y :
GB7. = B,,,
-
K I Z>
-
B DZ.
These differences, according to the theoretical model of the components of variance within and between pairs (Falconer, 1960) should contain solely the genetical (3 additive and $ dominant) variance. However, the interpretation of these estimates is of considerably limited accuracy as far ah it relates to the degree of genetic determination of the analysed characters, especially if the 11% itnd DZ total rariances are not equal. as was the case in a majority of traits included in the 1)resent study. In such a vase these par:tmeters are naturally biased as a result ofthe difference bet\\ren the t o t J varianccs. As has been denionstrated (see Christian et al. 1974), the withinpair ,tnd between-pair estimates are biased in opposite directions as a result of this difference. 'I'hcndoi~.the+> authors reronimentl their mean i i s a combined estimate of genetic variance, I\ hew thew. effects J i o d t l theoretically cancel, and n hich, a t the same time, is identical mith P~il(~on~ hrfitn ~ * .cwi-t\r h in ])airs component of genetic x-ariance (Falconer, 1 O t i O ) : A
6, 'l'=
(GI,,
h
iG , rr)/2.
-4i t l i r ,ilJwlnte \ ;ilucs of this parametcr cleprncl, to some extent, on the order of magnituclc of tlirl Ialuc of a given trait and thus. cannot be directly compared between the chamcaters in of the amount of genetic compoiicnt . their significance level is also indicated in the Tdblcx+.I t 1~ Iwen tc-ted by the ratio : (BMZ
+ J G z ) / ( ~ L )+z J G Z ) >
it11 thtl appi oxirn,itc*degrees of freedoin calculated as explained earlier for comparing the total \-ariances. This ratio is judged bv a one-tailed F test on the assumption that if genetic variance i:, prescnt, the expected value of the nuinerator is greater than that of the denominator (('hristian et ((1. 1974). Jnccluality of cov-ariances in N Z and 1)Z twins, which cannot be excluded, niay also bias this (or a n y ) estimate of genetic \ ariance. Therefore, considering the inaccuracy of the estimates, all the genetic parameters obtained in this study are mainly used only for making an approximate (+omprison of the degree of genetic determination of dermatoglyphic pattern elements and their (*ombinationssuch as pattern intensities, instead of attempting to estimate the precise proportion of the genetic rariaricc in the total variance for each character. \\
RESULTS A S 1 ) COJZMENTS
Thr. rwults for finger pattern intensities, finger and palmar ridge counts and some of the 1)dm.ti and sole measurements are presented in Table 1, a - for sexes combined, b - for males, aiitl for females. The data on palmar and sole pattern elements are given in Table 2 , r( - for w\;e\ conibinetl. b -- for inales. and c - for females. i.
Pulmar and sole patterns in twins
41
XZ-DZ differences between the means and the variances It is clear that the mean values or frequencies in MZ and DZ twin samples are llot appreciably different in the vast majority of pattern elements and measurements included in this stndy. This indicates that the values of these traits are not appreciably influenced by the type of twinning, a result which may be partly attributed to a considerable degree of genetical determination of most dermatoglyphic features. The fact that, in the present material, the observed differences between means are confined to the traits in which the non-genetical component appears predominant, such as minutiae counts and the ridge count on the Vth fingers, can be some indication of this. Unlike the situation with means, unequal total variances in MZ and DZ twins are not uncommon. It is particularly evident for finger pattern intensities and ridge counts and €or the thenar and overall palmar pattern intensity. At the same time, there is no convincing evidence for the inequality of between-pair mean squares for these traits except for pattern intensity on the thumb. This indicates that the difference in total variances may be largely attributed t o differences in the within-pair mean squares, related t o a considerable degree of genetic determination of these traits. It should be observed that, a t the same time, all genetic parameters for these traits are relatively high. However, if there is strong indication for the inequality of both the total and between-pair mean squares, such as, for instance, in a case of the z’’ sole triradius in males or the palmar anti sole loop I1 in females, it may be assumed that these differences are related to different environmental influences in both types of twins. Indeed, all the genetic parameters for these characters arc relatively low. The situation is apparently different in a majority of sole patterns, some palmar patterns and the sum of distal loops, where the between-pair mean squares are clearly unequal, while there is no convincing evidence for the inequality of total variances. At the same time, most of these characters have relatively high genetic parameters according to the present data. The reason for such an inconsistency may be that MZ-DZ differences in respect of within-pair mean squares and between-pair mean squares balance each other and the inequality of environmental influences in two types of twins is not detectable by comparing the total variances. At the same time, however, such a phenomenon may be evidence that the MZ-DZ differences in respect of the within-pair similarity are, for such traits, increased by non-genetic influences such as a common prenatal environment in MZ twins. This would naturally increase the estimates of genetic parameters as obtained directly from the mean squares. It is also evident from the Tables that the differences between MZ and DZ total and betweenpair mean squares are, for a large number of characters under this study, not consistent in the two sexes as regards magnitude and direction, which makes the interpretation of these differences as well as the estimated genetic parameters based on twins even more elusive. Genetic parameters At the same time, the approximate estimates of genetic parameters, such as the within-pair variance ratio, MZ covariance/variance ratio and 6,, genetic variance, obtained in this study are, except for some palmar loops, consistent in both sexes. Although for the reasons discussed earlier in this paragraph, these estimates should be considered with caution, they indicate
+
distance
a-b count Minutiae ( E ) Minutiae (I) Soles e count f count
c- d
IV V Total Palms a-b distance b-c distance
I1 I11
I
Ridge coillit
'I'otnl ( / ' I f f ' )
=milid
C",
(IV+ V)
( I 11) (I+II+ITI) (111+ I V + V)
v
IV
JII
I I1
l " l ~ t l ~ t ~ 1Ill(l.ll~lty 1
1~'lIlgyr~
Cll;ll~'ll~t ('1's
0.008 0.025
1.419 428-366 1.871 683.133
18-25 2.001 13.90 47-48 2.538 52'77
0.002
1.387 7.206 14.561 I I 769 5'039 4'25 I 3.862 7.912
2'010
2.172
2.81I
2.090
(4
I 8.901 11.514 5'514 9.063 7'523 8.604
10.81I
2.378 1'333
2.505
3'009 4.018
( Jf')
I+t wt V ~ l l W i t I iiri ptiirs pirs
9'393 9'407
I 2.690
6.071
12.588
3'537 4'777 2.882 3 '447 1.213 11.833 19'922
MZ
5.099 0.01 0.06 6.829 0'01 0'10 4.677 0.00 0.48 4.388 0.09 0.10 2.720 0.00 0.98 18.017 0'01 0.05 33.462 0'00 0'20 23.283 0.00 0.69 10.553 0'00 0.55 13'314 0'73 0'00 I 1.385 0.17 0.35 16.516 0'00 0'34 1
0.008
53.537 96.491
0.023
18.441
0'001
0.001
0.001
221.471 385.106
0.018
99.655 0.007
0.002
0.005
0'002
0.00~
0.003
0.003 0.006
501.065 880.061
118.456 216.236 0.016 0.015 0.048 0.041
0.003
0.003
279.594 481.903 494.955 779.624
0.023
0.008
116.581
0.001
0.001
0.001
7,274
1.000
8,691
7.011
8.066 5.105
0.00 0.00
0.44
0.04
0.28
0.53 0.49
5.130
5.222
1.000
1.000
6.322
1'000
1.00 1.000
0.99
0.81
0.64 0.24
0.00
0.68
0.00
0.00
47.100 260.100 342.617 508.599 602.717 0.29 0.00 53.468 3 2 I .560 43 I '284 476.528 752.844 0.00 0.08 48.291 26 I '443 250.869 356'538 512.312 0.02 0.19 43'702 306.092 306.401 395'595 612.493 0.01 0.23 I 3.068 140.592 I 13'577 I 50.872 254.169 0.00 0.54
0.836
5'21 I
0.69 I 0.873 0'291 I ,964 2.800 1.891 1.164 5'032
1'200
0.727
100.015
0.002
0'001
0'005
0.013
461.499 423.060 308.247 351.893 137.804 2095'I54
0.007 0.004 0.952 0.008
1.538 1.710 1.542 1.668 1.131 3.692
2.810 3'577 2.191 2'574 0.922 9.869 17.122 10.697 4'907 7.658 4'152 8.571
0.39 0.003 0.37 0.26 0.004 0.29 0.36 0.004 0.34 83.57 0.958 83.28 0.82 0.008 0.84 0.75 0.015 0.67
47.91 36.60 32.52 47.48 30.07 147'75
0.1 60 5.69 0.138 0'1 81 5.69 0.160 0.142 4.84 0.141 6.09 0.135 0.154 0.092 4.69 0'1 I 2 0.301 11'37 0.256 0.396 16.21 0.364 0'313 I 5.61 0.327 0'21 2 10.78 0'214 0.265 4.04 0.197 4.21 0,187 0'195 0.280 13'49 0.268
45'34 2.058 32.80 1,979 31.76 1.682 45.38 1.805 28.67 1.124 145'45 4.384
5.36 444 5.91 4.36 10.80 I 5.64 15.11 I 0.27 4'04 3'93 I 2.96
5 '44
(It')
p i i x
\Vit I I i 1 1
Table 1 a .
216.476 348.246
0.78 0.75
0.001
0.004
49,250
0'000
-0.002
0.69 -0.04 0.04
0.31
0.20 0.28
0.81 0.78 0.72 0.78 0.83
0.82
-0.12
0'21
0.67 0.72 0.70 0.62
0.52
0.49
-0.001
I
0.50
0'52
I
0.59
'50 r ,792 0.917 "034 0.289
,
+
t j
radial
uinar
0.40 0.26 0.35 83.06 0.77 0.75
42.37
Palms a-b distance b-c distance c-d distance a-b count Miriutiac (E') Minutiae (I)
Soles e count f count
Iv
V Total
16.12 15-48 10.48 5'29 4'33 13'29
11'12
6.10 4.38
5'00
5.60 5'52
iv
49'22 33.70 33.36 48.20 31.10 153.03
I I1 I11
Ridge count
Total ( P I F )
C
'
+ + +
I I1 I11 IV V (I 11) (I I1+ 111) (111s.I V +V) (IV V)
Fingers Pattern intensity
Characters
4.04 4'3 1 13.86
11.15
4'97 6.19 4'95 11.61 16.58 16.1 I
5.82
5'79
@ L
7
5.662 48.57
2'357 0.936 8.670 15.370 9'550 4'550 7'702 3'549 7'552
2'200
3.001 2.950
1.305
2.086
0.017
458.498 624.609
0'002
73.084 0.006 0.030
0.005 0'012
0'002
Mean squares
0.001
0.001
0.001
0.001
0.002
336.290 449'395 290.064 284.105 130.258 1116.983
2.419 4'032 2.968 2.581 1.839 9'548 I 8.452 13'774 6.742 10.960 7.968 8.952
(W)
0.004
259'525 308.066 263.497 344'397 141.570 1450.885
I '773 2.092 1.562 5'592 I I '340 I 1778 5.608 3.801 3.874 7.181
2.114
1'875
(a
Between WitEiiii pairs pairs
r__h_7
DZ
-
0'00
0.002
0.002
0.005
0.003
240.886 0.018 0.016 0.057 0.038
0.003 0.003 91.892
0.03
0.55 0.03
0.00
0.32
0.01
262.209 529.903 503.147 0.79 502.258 708.591 767.760 0.72
0'021
0.017 0.027
71.405 240.938 83.982 265.502
0.008 0.008
0'012
0.06
0.58 0.79 0.79
0.05
0'00 0.01
0'20
0.32 0.97
0'01
0.10
0.03
P,
0.04
0.40 0.04
PT
r-----h7
4'032 3.456 4'450 3'521 6.130 6993 8.263 6.775 6.527
1.000
9,182 8.180 6.157 7.094 8.791 5.998
0.00
0.01
3.672 5.981
1.056 0'457 5'530 10.124 4'757 2.325 4.893 1.567 4.358
0'20
0.73 0.76
204.182 388.691
43.767 0.003 0.003
0'000
-0.001
0'000
292'575 234.616 160633 112'353 49'343 0.81 614.705 0.87 0'75 0.76 0.78 0.78
0.99 1.000 0.31 0.17 1.000 0.33 0.91 7.288 0.59 0.90 0.667 -0.33 0.04 0.02 0.778
0.11
0.16 0.59 0.69 0.23
0.20
0'00
- 0'1 2 0.85
0'20
0.69 0'75 0.65 0.63
0.5 I
0.67 0'43 0.53 0'52
Within MZ pair cov/ variance var ratio ratio
7
12.350 0'00 14.761 0.45 0.00 2.160 I I .842 0.04 0.63 I .768 16.133 0.00 0.42 i'4'724
25'552
4'294 6.146 4.741 4.673 3.401 15.140 29'792
DZ
difference
581.635 595.815 0.93 437.785 757.461 0.01 388.915 553.561 0.10 365.100 628.502 0.01 139.631 271.828 0.00 1935.746 2567.868 0.19
3.601 4.117 2.867 3.090 1.236 10,237 I I .603 11.583 5.583 12.777 8.057 8.160
MZ
Total (2')
MZ-DZ
level of
I+
w
s*
2
9
&?
g r
s
_L__-____ Significance Genetic parameters
18.808 103.813 137.072
0.001
0.001 0.001
0'001
0.006 0.009
36.625 54'941 47.108 40.05 I 14.817 186.217
0.600 1.167 0.667 0.733 0.300 1.567 2'233 2'033 1.033 5'075 4.508 0.608
Between Within pairs pairs (B) (W')
7 -
MZ
2.062 545.010 2'247 382.844 2.078 341.807 2.376 325.049 1.523 I 24.814 4.877 1749.529
0'175 0.186 0.171 0.185 0.160 0.302 0.43 1 0.439 0.303 0.250 0'252 0.343
S.E.
4
7
DZ
49.19 37'52 33.40 49.70 32.84 152'34
A
0.35 0,004 0.33 0.006 0.006 0.32 1.113 81.67 0'010 0.85 0.023 0.64
3'039 2.569 2,407 2.367 1.454 5'445
0.402 0.278 0.361 0.245 0.358
0.510
0.179 0.224 0'193 0.176 0.126 0.383
S.E.
MZ
7
Means
7 -
(Moans ( B )standard , errors (s.E.) and mean squares ( B ,TY,T ) ,significnnce l w d of MZ-DZ differences in respect of total ( P T )and betwern h ( P B )mean squares, within-pair DZ/MZ variance ratio (P),MZ covar.isiree/variance ratio and G,, genetic variance for pattern intensities and som0 finger, palmar and sole dermatoglyphic measurements (left and riglit combined) in a sample of 60 MZ and 62 DZ male twin pairs.)
Table 1b.
f count
SOlc?S e count
Total Palms a-b distance b-c distance c-d distance a-6 count Minutiae ( E ) Minutiae (I)
V
IV
I1 111
I
Total ( P I P ) Ridge count
=radial
="I,
+
+
V (I 11) (I+ I1 + 111) (111+ IV + 1 7 ) (IV V)
117
I I1 I11
Fingers Pattern intensity
Characters
0.208
0.226 0.295
2.561 3.092 2.309 2'722 1.677 6.937
13.55 53.31
2.681 3.742
r-L-7
MZ ( P A - - ,
5'55 5'5 I 4.67 5.96 4'35 I I .06 15'74 14.98 10.31 4'03 4.08 13.02
2'329 3.638 2.628 I ,876 0.961 9.078 18.236 I I '040 3'927 4.821 3.810 8.449
87.008 0.005
0.016
18.000
0.004
0.018
131.647 0.005
0.019
0.010
0.018
32.810 193'771 110.750 485.849
0.001
0.001
0.001
352'301 686.077
0'001
0.001
0.001
0.001
0'001
0.001
0.006 0.005 1.346
59.670 256.070 51'730 336.182 49.710 256.601 48.010 243.505 10.970 117'418 83.590 1501.316
1'110
2.440 3.480 I '720 1.320 4.980 6.120
0.280
0.880 I 240 0.720 I ,040
0.005
12.59 2.009 3.181
58.02
0.40 0.24 0.37 85.31 0.84 0.71
7.280 4.468 9'493
5'220
2'738 0.904 I I '044 18.616 I 1'704
2'1 I 0
2'502 4268
321.364 468'430 261.184 2'252 363.101 1.564 137.783 5.593 2358.090
2.310 2.646 2.312
0.420
0.282
0.275 0.234 0.198 0.141 0.435 0.616 0.480 0.286 0.3 I 7
0'220
301.591 485.714
90.653 0.008 0.026
0.001
0.002
0.001
350.622 408.367 201'275 334.612 92.469 1529.255
0.694 I 2.408 19.469 8.653 3'959 6.663 6.959 8.163
2'123
3'755 4.000 1.918
(W)
Within pairs
DZ
3.382 5.508 2.830 3.778 1.184 13.484 22.096 13'424 6.540 I 2.260 10.588 10.603
MZ
0.002
0.05 0.14 0.09 0.15 0.16 0.39
0.40 0.75 0'93 0.06
0.10
0'02
0.14 0.03 0.79 0.13 0.04
0.01
4.267 3.226 2.664 2041 2'479
0.13 0.48 0808 0.29 0.06
0.22
0'29 0.34
0.08
5.876 7.894 4.049 6.970 8.429 18.295
1.338 1.137 7'354
0 . ~ 5 5.085 0.47 5'595 0.42 5.031 0.16 2'999
0.58
0.10
0.40 0.29 0.78
o.002
385.111 495.362 0.30 796.827 971.563 0.40
0.002
0-12
0.02
9.192 4.386
G,,
0.000
0.83 0'72
0.03
213.656 287.596
0.006
0.003
58.646
0.22
0.76 0.16
0'000
0.23 0.16
0'000
78.075 203,099 0.85 50.932 0.93 1151.2rg
0.68 0.77
178.123 0.80 244'44.3 0.69
var ratio
COV/
MZ
parameters
-
Significance Genetic level of ( - - . A - ~ MZ-DZ Within difference pair c--~-,variance PT PB ratio
0.40 0'73 1.000 0.04 0.76 2.000 0'002 0'002 0.95 0.15 1.000 149.647 177.661 0.47 0.08 5.036 0.009 0.013 0.04 0.41 2.000 0.042 0.61 0.23 1.444 0,037
0.002
606.692 744'549 457.876 578.117 209.887 3030.571
6.084 7.638 4.546 3'999 1.655 21.486 37'705 19.693 7.886 I I -484 10.415 16.612
DZ
Total (T)
381.034 520.160 310.894 411'202 148.753 2441.680
Mean squares
Bctween Within Between = A 7 pairs pairs pairs A!f S.E. (B) (W ) (B)
DZ
46.28 35.43 31.40 44.67 26.57 141.95
0.39 0.004 0.26 0.005 0.36 0.005 84.18 1.639 0.86 0.010 0.76 0.020
40.67 31.73 29.83 42.05 25'75 136.35
0.236 0.136 0.475 0.616 0.489 10'02 0.326 4'52 0.385 3.46 0.302 12.55 0.440
5'24 5-18 4.64 5.68 4'34 10.42 I 5.06 14.66
%=
MZ
r - A - - 7
Means
7 -
(Means (%), standard errors ( s . E . ) and mean squares (B, W , T), significance level o f MZ-DZ differences in respect o f total ( P T )and between ( F B )mean squares, within-pair DZ/MZ variance ratio ( F ) ,MZ covariance/variance ratio and ,& , genetic variance for pattern interisit,ies and some finger, palrnar arid sole derniat,oglypliic ineasureinent,s (left and riglit combined) ill a sample of 50 MZ and 49 DZ female t,win pairs.)
Table l c . cp cp
Palmar and sole patterns in twirLd
45
(see Table 1 ) that, on finger-tips, both pattern intensities and ridge counts on individual fingers (exc.ept for finger V), as well as all their combinations may be strongly genetically determined, but genetic influence is much less appreciable if the ulnar and, especially, radial components are summed up over all ten fingers. B s concerns some other dermatoglyphic measurements presented in Table 1 the results indicate that, while the traits such as the e and f hallucal counts and the a-b ridge count may be strongly genetically influenced, the oppositt: is true for the intertriradial palmar distances and the minutiae counts ;particularly these last two measurements, E and I,appear t o be almost entirely determined by non-genetic influences, although generally low variability of these traits renders them inconvenient for the purpose of genetical analysis. Amongst the palmar and sole loops and triradii (see Table 2) the highest values of genetic parameters apparently concern all loops on soles, except for those in the area 11, and most of sole triradii, as well as all combinations of these Ioops. On palms, if loops are considered separately, consistently high values of genetic parameters are obtained only for the hypothenar distal loop €I and the axial t triradius, but they are also high for a majority of combinations of p l m a r loops; the same is true for the combination of all distally displaced triradii, t’, t” and t ~ It. is worthy of note that, as for finger patterns and ridge counts, presented in Table 1, these parameters are relatively higher for some combinations of loops, such as hypothenar loops and the s u m of interdigital loops than for the total pattern intensity on palms. This may be evidence that several pattern elements, or some combinations of pattern elements in any specified area (or in adjoining areas) are each influenced by a specific genetic system which modifies their phenotypic expression. It may also be of interest that genetic variance is not higher for anatomically intercorrelated loops (in brackets) as compared with combinations of independent pattern elements. The values of genetic parameters are generally higher for most of the characters, if sexes are combined, in spite of not always consistent results in this respect in the male as compared with the female samples, which may thus be related to a considerably modifying effect of a sample size. The estimates of genetic parameters obtained in this study for palmar, sole and finger patterns are generally in agreement with the values of the concordance rate in MZ and DZ twins and with several other ‘heritability’ estimates in the same sample of twins (Loesch & $wiqtl;owska, 1977). It is realized, however that they may all be considerably biased by the fact orb already discussed or demonstrated here. Moreover, the possibility of genetical differences bet\\rern the two members of the same pair of identical twins, which would be extremely tlifficult to distinguish from the non-genetical influences by means of traditional methods such as applied here, are believed to be an additional source of bias in the results concerning genetical pammeters (Kempthorne & Osborne, 1961; Allen, 1965; Kang et al. 1977). Although most of these may be eliminated by applying more sophisticated procedures of twin analysis such as those recently introduced and based on methods of biometrical genetics (Eaves, 1973; Eaves & Eysenck, 1975), some factors such as inequality of covariances may still influence the estimates of genetic parameters based on twins. It should not, therefore, be unexpected that the results of different twin studies, even if they are bascd on similar methodologies, are often inconsistent. Some of the data obtained in this study are not in good agreement with the GcT estimates by Reed et al. (1975),which particularly concerns the thenar loops, I+P,on palms, and sole loops in the areas 11, I11 and IV. I n both
MZ
0.089
0.079 0.094 0.048
0.038 0.069 0.079 0'057 0.059 0.03 I
0.082
0.05 I
0.136 0.083
0.1 32
0.87 I + I ' + I I + 111 1'94 Pattern intensity (PIP) 3.38 t' + t" + t" 0.98 Soles I I .78 f 0.76 I1 0'20 $1 0.60 111 1.41 If1 0.30 IV 0.35 I? 0.07 ? 0.99 P+P' 1.61 P" 0.26
+ +
0'100
0.28
0.79 1.63
0.08
I .78 0.77 0.19 0.61 I .46 0.34 0.36
0.83 1'99 1'35 0.87 2.07 3'30 0.94
I '04
0'20
0.52 0.04 1'35
0.5 I3
0.062 0.066
0'032
0'177 0'223 0'105
0'102
0.688 0.973 0'249
0 105
0.024 0.069 0.068 0.049
0.05I
0.360 0'375
0'077 0.114 0.118 0'255 0'105 0.114
0'200
0 ' 1 I8 0.3 I 8 0'414 0'377 0.382 0.359 0.814 0.664
0'513 0.269
0.522
0.419 0'477 0.272 0.285 0.062
0.136 0.449 0.076
0'390 0.078 0.535 0.400 0.481 0.554 0.473 0.710 0.628 1.562 1.914 0.556
0'277 0.064 0'200
0'220
0.033 0.438 0.526
1)tlIrs
0'100
0.064 0.246 0'359
(If.)
p~lll's
0.050
0.681
0.156
0.726
0.280
0.862 1 '903 2.004 0.745
I .080
0.766
0.807
0.080 0.472 0.496 0.326 0.429 0.062 0.662 0.31 I 0.641
(11)
p irs
0.026
0.035 0.064
0.017 0.063 0.069 0.045 0'059 0.027 0.070 0.060 0.066 0.07 I 0.066 0.080 0.076 0'119 0.132 0.071
0.08 0.96 0.95 0.31
0.027 0.066 0.067 0.055 0.063 0.024 0.078 0.053 0.077 0.086 0.084
I '27
2.15
0.79
1'01
0.15
0.08 I '24
0.52
0.26
0.08 0.93 I '14
S.K.
1 V
s ,133.
-.A 7
-nf
0.347 0.523 0.329 0.3 I I 0.059 0.478 0.914 0.266
0.180
0.315 0.496
0.460 0.248 0.496 0.824 0.7 I 2 0.766 0.878 1.523 1.892 0.680
0.081
0.357 0.840 0.274 0.768 0.786 0.474 0.480 0.134 0.865 1.196 0.354
2.717 2.668 0.945
1'221
1.143 1.462
1'221
0.825
0.718 0.855 0.426 0.706 0.126 0.862 0.429 0.959
I '427 0.535
1'000
0'121
0.66
0'00
0'00
0.03 0.07 0.07 0 07 0'00
0'1 I
0.15
0'01 0'00
0'00
0.41 0.06
0.15
0.05
0'01
0'01
0.3 I 0.89 0.13 0.91 0.07 0.03
0'02
0.35 0.62
0'00
I'll
0.14 0.46 0.33 0.24
0'12 1'000
0.45 0.64 0'99
0'12
0.07
0'01
0.90 0,38 0.80 0.95 0.14 0'37
0'00
0.33
0.08
0.03 0.31 0.04 0.03 0.46
I'T
0.601 0.596
0.45 1 0.945 0.256 0.766
1.130 0.589 0.782 0'159 0.995 0.648 0.977 1.379 1.185 1.476 I ,506 3985 3.806 1.236
0.105
0'I44
DZ
0.387 0.604 0.369 0'392
MZ
0.072
( 117)
pairs
1.125
2.962 I444 2.701 4.099 2'533
2,886
4.091 4'35' 1.525 1.361 4.981
2.446 1.871 2449 3.400
2.005
1.888
1.560 1.990
2'IOI
2.300
3.690 1'415 I ,266
1.682
1.573
0.152
0'149
0.034 0.234 0.576 0.071 0.53 0.59 0.63 0.41
0.311
0.56
0.071 0.093
0.330
o.rgr
-7
0.34 0.73 0'52
0.57 0.73 0.14
0.58
0.50
0.54 0.45 0.34 0.32 0.34 0.48 0.41 0.40
0'01
0'21
0.32 0.16 0.53
0 ' 1I
var rntio
rev/
p iI' variaricc
ratio
MZ
\Vithiii
+
0.42 0.36 I -66 I .96 3'07
loops
loops
+ soles
'pmnimd
'distal
Palms
+ +
6.48 3'35
0.42 I -72
0.44 0'121
0.075 0.048 0.014 0.068 0.073 0.087 0.058 0.061 0.808 0.741 1.165 0.457 0.650 2.426 1.385 3.493 2.564
0.055
0.803 0'391
2'00
0.198 6-50 0.161 0.195 3'19 0.158
0.113
0.264 0.768
0.500
0.505
0.173 0.400 0.173 0.136 0.146 0.527 0.209
0.023
3.636
1.532
0.840 0.365 0.415 I .605 0.925 2'394 I .920
0.582
0.506
0'021
0.159 0.625 0.096 0.259
4.288 0-723 2'499 4-1-57 0.923 2'736
0.092 0.179 3-18 0.I 48 2.60 0.132 0.153 0.136 2.23 0.118 2.080 0.229 6.40 0.182 5.693
0.065 0.077 0.149
0.103
I 71
0.80 I -80
0.03 2.55
0.35
0.060 0'022
0.086 0.082
0.86
0.086
0.04 2.54 0.80
0.89 0.31
II+r^I+III+IiI* 2'5 I 2.13 (111+ If1 rv IV ) Pattern intensity (PIS) 6.48
(f + fI + 111) I1+ III+ IV (1+ fi+ I11+ 111)
(I1 I^I! (III+III) I V +I F (If1+ IV)
I+i
z"
' 2
z
Table 2a (cont.)
2.946 2.856
0.21
5.011 5.080
5.445 5'592
0.09
0.01
0.00 0.01
0.52
0'01
0.59
0.33
0.13
0.07 0.06
0'27 0.12
0'02 0'02
0.13
0'02
0'12
0.62 0.77
0.04
0'10
0.01
0.00
0.02
0'12
0.29 0.09 0.73 0.06
0.64
1.035
0.588 0.067 1'272 1.199 1.800 0'743 0.856 3'092
0'593 0.796 2.953 1.594 2'020 3'998 4745 3.064 3.875 2.344 2.978 6.461 7.514
1.338
0.962 0.487 0.078 0.981 1.142
0.30
0.67 0.61 0'42 0.65
4.075 3.094
0.71 0.64
0.74 0.54 0.63 0.64 2.822 5'239 0'73 4'6.55 0'75 3.910 0.67 5.477 0.77 5.049 0.76
2.579 3.427 1.961 4.428 1'543 5.549 2.779 3.021
(a),
+ +
+
+
z
P"
P+P'
e
1I1 I11 If1 I? IV
P
I
Sole patterns
l'+t"+t"
S.E.
+
0.045 0.089 1-19 0.094 0.083 0'35 0'43 0.078 0.13 0.041 I .28 0.099 0.23 0.094 1 . 1 3 0.109 0.78 0.118
--
-
0.092 0.086 0.050
0.103 0.130
0'10
0.83 I .78 0.36 0.98 0.118
0.074
0'100
0.049 0.093
0'1 I 2
I .80 0.80 0.19 0,64 1.57 0.41 0.47
1'01
0.86
0.28
1.78 0.77 0.19 0.61 I .46 0.34 0.36 0.08 0.79 I .63
0.141 1.35 0.I 26 0.87 0.193 2.07 0.207 3'30 0'110 0.94 0.065
0.123
I .48
0.83 1.99
0'20 I '04 0'250
0.891 1.170 0.935
0'995
0.596 0.495 0.441 0.148 0.631
0.509
0.743 0.I 42
0.252
2.526 0.712
2.192
0'101
0.820
0.326 0.098 0.150
0.217 0.529 0'250 0.491 0.142 0'303 0'175 0.622
0.444
0.903 0.218
0.081 0.436
0'290
0.321
0'125 0.050
0.323
0.091
0.447 0.438
0.092 0'275 0.067
0.540 0.218 0.355 0.460
0.331
0.457
0 ' 150
1.234
1.189 0.496
7
3.150 3.101
1.141 I .628 1.285
1.311
1.055
0.720 0.884 0.553 0.662 0'I99 0.787 0.671
0'220
MZ
0.876 0.234 0.784 0.663 0.621 0'591 0.198 0.848 I '245 0.468 0.995
0.302
PT
0'521 I .066
0.898 04344 0.616 0.179 0.965 1.394
0.802
0.481 0.997 0.309
0.57 0.74
0.5 I 0.58
0.54 0'1 5 0.91 0.16 0.87 0.83 0.59
0.03
2.ooy
2.584 1'933 I .620
6.866
6.620 4.060 2'370 1.291
2.752
2.146
I '204
3,612 0.39 1'535 0.14 2'537 0'00
0.25
0.06
0'12
0.05
0'1 2
0.04 0.3I
0.03
0'02
0.08
0'00
0'02
0'1 2
0'01
0'00
2'120
1.601 1.487 3.000 1.539 0.03 0'1 I
1'020
2.288 0.26
0.80 0.60 0.49 0.49 0.49 0.60 0.40 0.65
0.30
0'22
0.67 0.69
0.233
0.040 0.160 0.575 0.049
0.1 28
0.186
0.275
0.191 0'347 0.089 0.071
0.537 0.998 0'334
0,317
0.241
0.229 0.524 0.390
0.26 0.56 0.44 0.45 0.39 0.63 0.47
0.179 0.092
0'002
0.32
0.47 0.55
1.050
0.400 -0.01 0'00
0.05
GCT
0.041 0,093 0.19 0*182 0,46 0'193 0.09 -0.027 0.28
0.09
MZ cov/ var ratio
0.75
0'00
2'260
1.469 1.802 0.27
1.120
0'00
Within pair variance ratio
Genetic parameters
0.28
PB
Significance level of MZ-DZ difference
0.173 0'12 0.69 0'777 I *094 0.25 0.544 0.93 0.656 9'52 0.075 0'00 0.965 0-30 0.495 0.13 I .003 0.78 1.322 0.97 1.093 0.82 1.336 0.30 1.435 0.57 2.466 0.19 2.423 0'21 I .206 0.27
DZ
Total (2')
0.710 0.970
1.153
1.313
0.430 0.604 0.343 0.634 0.693
0.379 0.645 0.339 9.3I5 0.040 0.476 0.153 0.573 0.718 0.750 0.702 0'742
0.113
0.133
0.050
0.258
0.458 0.350 0.958 0.575
0.358 0.483
0.828
0.697
0.208 0'1 5 0
0.071 0.326
0.090
0.086 0.039 0.086 0.085 0.072 0.073 0.040 0'093
0.050
0.090
0'I47 0.I 40
0.I 07
0'102
0.300
0'342
0.431 0.035 0.489
0.150 0'100
0.205
0.358
0.050
0.398 0.449
0.258
0'100
0'521
0.462 0.526 0.403 0.362 0.099 0.579
0.081 0.086 0.058 0.084 0.024 0.089 0.075 0.084 0.099 0.075
0'1 20
0.029
0.96 0.95 0.3 I 0.52 0.04 1.35
r-h---,
DZ
Mean squares
Between Within Between Within pairs pairs pairs pairs S.E. (B) (W) (B) (W)
+ 7
MZ
0.08
iv
DZ
2.32
1'01
0'1 2
AT?
MZ 7
7 7
0.92 I +I'+II+111 H + A 2.14 Pattern intensity (PIP) 3.64
H+A+H'
(I 1') (I1+ 111) (H A) I1+ 111+ IV (I1+ I11 H)
t
Iv H A H'
I1 I11
Characters Palmar and sole patterns
Means
r
(Means standard errors (s.E.) and niean squares ( B ,W , T), significance level of MZ-DZ differences in respect of total ( P T )and between ( P B )mean squares, within-pair DZ/MZ variance ratio ( F ) ,&I2covariancelvnriance ratio and G,, genetic variance for topologically significant pattern elements of palms and soles and pattern intensities in a sample of 60 MZ and 62 DZ male twin pairs (left and right combined).)
Table 2 b .
W P
M
0
m
P
+
l0WB
zproxima~loops
&.td
Palms + soles
+
(If1+ IV) (f 4-I? t 111) 11+ I,II IV (1+ I1 +I11 + 111) I1 + f I + 111 + IIIA (III+ 111 + IV + IV) Patt,ern intensity (PIS)
rv+Ik
I+f (I1 11) (111+ 111)
2"
d
7.02 3 '40
3'42 2.81 2'54 6.83
2.23
1.85
0.5 I
0.43 0.06 2.60 0.83 I -98 0.57 0.35
0.293 0.276
6.50 3'19
0.867 1'100
5.050
4'490
0.173 0.223
3.718
1.331
1'742
5'9x7 5'590
4.605 6.083
0'00
0.07
0'22
0.68
0.83
0.23
0-23
0.90 0.47
2.025
4'372 3'579 3 '05 5 7'711 4'243 3.076 2.369 6.73I 2.032
0.06 0.09 0.04 0.09 0.27 0.17
0.02
0.32
0.10
3.200 2.771
0.07 0.29 0.13
0.29 0.26 0.37 0.76 0.88
1'143
4'7331 1.916 4.226 1.935 2.857 2.614 4.804 3.584 3.667 3.892 4.551
0'00
0'00
2.669 0.02
0.85
3.152 I .670
3'255
0.674 0.071 1.336 1.130 1.383 1.345 1.697 0.696 0.826 1.104 I '042
0.649 0.126 0'974
1.524 1.081
0.500
0'379 0.048 0-790 0.734 0.879 0.387
1.831 2.774 3'035 3.048
0.070 0.507 0.142 0.295 0.03 0.019 0.084 0.042 0.023 2'55 0-095 0.807 0.167 0.546 0.80 0.103 0.747 0.383 0.649 0'112 1.137 0.208 0.818 0.139 I .80 0'1I5 0.092 0.44 0.085 0.496 0.200 0'439 0.126 0.42 0.094 0.929 0.175 0.542 1'72 0.168 2-569 0.583 1.731 02og 2 '00 0.124 0.151 1.345 0'22.5 0.943 3.18 0.196 3.676 0.567 2.340 0'250 2.60 0'1 74 2.601 0.475 1.837 0'210 0.185 2.23 0.168 2'027 0'342 1.724 5.914 0.817 3'993 0.317 6.40 0.256
0.093 0.038 0.117
Table 2 b (cont.)
0.61
0.71
0.56 0.34 0.66 0.32 0.69 0.42 0.68 0.63 0.71 0.73 0.69 0.71 0.76
& &
O1
Q
.Y q
1'702
2.563
E'
3 3'
0.356 0.890 0.629 ?2 1.401 1.015 0.646 2.411
0.122
0.495
0.225
0.225
0.034 0.442
2
0'112
0.07I 0.083
1.22
0.33 0.65
I8 0.433 0.054 0.352 0.488
0'1
0.296 0.439
0.55 I '23 0.16
0'21
0'121
0'102
0.059
0'1 I
0.27
0'442 0.791
0.190
1.053
0.054 0.826
0.3 I I
0.414 0.871 0.187 0.689 I .090 0'542 0.569 0.045 I '041 I .396 0.552
1.301
0.14 4.085 0'02 4489 0.97 5'450 0'00
0'22
3.000 0'00
0'32
0'01
0.41
1'465 4.013 3'370 6.740 0'00
0'10
0.72 0.33
2.691 4478 0.887
3.109 3'539 4.946
0.48 0.77 0.06 0.38 0.66 0.24 0.68 0.63 0.68 0.64 0.37
0.71
0'22
0.64 0.35 0.38 2.841
0'01
1.251
0.40 2.921
0.33
1'474 2.906
0.09 0.78 0.34
0'00
0'01
0.05
0'00
0.23
0.92 0-69
0.05
0'52
0.34 0.71 1.641 0'1 I 0.39 1.559 0.14 0.08 3.865 0'00 0.81 5'490 0'00 0.99 I ,265 0.16 0'21
1.111
1'00
0.48
0'00
1.073 1'154 1.139 2.090 1.970 0.913
I '00
0.14 0.83
035 0.84 0.65 0.09 0'00
0.62
0'00
0.08
I', 0'00
0.997 0.836 0.926 1.438
0.258
I', 0.03
0.949 0'1 I8 0.808
0.030
0.030
0.743 0.872 0.264
0.701 0.090 0.171 0'1 50
0.095 0.033 0.086
0'1 I 0
0.313
0.050
1.990 2.725 0.643
1'05 I
1)Z
0.048 0.696 0.880 0.814 1'159 0'254 0.648 0.738 0.819
MZ
0.38 0.230 0.337 0'513 0.602 0.722 0.150 1.19 0'101 0.058 0.26 0.065 0.164 0'I 0 0 0.205 0.337 0'21 0.050 0.232 0.337 0.073 0.32 0.069 0.261 0.03 0.030 0.03 0.017 0.044 0'010 0.014 0.03 I 1.17 0.119 0.86 0.103 0.696 0'130 0.5 I 0 0.531 1.28 0.099 0.863 0.190 0.470 0.929 1'39 0.133 0.14 0.052 0.29 0.068 0.130 0.060 0.225 0.327
I .83 0.66
1'200
0.783
I
0.408 0.490 0.1 33 0.439 0.367 0.398 0'9.59 0.663 0.847
0.551
0.398
0'020
(It')
J)tlil.R
0.321
0'120
0.080
0'1 25
0.190 0.558 0.080 0.469 0.270 0.528 0.330 0'479 0'530 0.638 0.290 0.794 0.370 0.508 0.640 1.875 0'770 2.765 0.130 0.623
0.250
0.488
0'759 0.038 0.538 0.781 0.543 0.864 0.769 1 '450
0.360 0.040 0'020
0'230
0.466 0'454 0.214
0.028 0.482 0.608 0.240 0.329
(J4
Iniw
0'010
0'020
(It')
p 1 II's
0'010
(14
1 I i L I 1's
0'133
1'75 0.71
0'02
0.014 0.15 0.05I 0.108 I '09 1.19 0.124 0.04 0.028 0.27 0.099 0.87 0.105 0.87 0.105 0'79 0.126 0.98 0'100 1'99 0'1 I 5 1'95 0'105 I '03 1.19 0.129 0'133 0.81 1.13 0'I 03 0.1 25 I '70 0.172 2.13 0.198 3'07 0.156 3.64 0.240 0.95 0.126 I '07 0.114
0'I 0 0
0'I00
0.85
0.83 I .08 0.16 0-63
0.014
.
0'02
h .l',
7
0.024 0.098 0.096 0.066
,
0.04
r--
rl I
-
s.1.:.
i
A1
