Hum. Genet. 37,319--328 (1977) © by Springer-Verlag 1977

Genetic Markers in Libyan Jews Batsheva Bonn6-Tamir, Sarah Ashbel, and Jehudit Modai Department of Human Genetics, Sackler School of Medicine, Tel-Aviv University, Ramat Aviv, Israel

Summary. Blood groups, serum proteins, and red-cell enzyme frequencies were determined on a random sample of 148 Libyan Jews now settled in Israel. Comparisons with data on Libyan non-Jews show significant differences in most systems, implying maintenance of a high degree of genetic isolation of the Jewish group from surrounding populations. The relative lack of the African component in their gene pool shows that they have interbred very little, if at all, with their negroid neighbours.

Introduction As part of a large series of genetic studies on similarities and differences among various Jewish communities now settled in Israel, a sample of Libyan Jews who migrated to Israel in the fifties has been investigated. One of the objectives of this series of studies is to obtain genetic data which will enable a fuller genetic characterization of those communities which today comprise the Israeli population. It was hoped that this characterization might throw light on the nature of the association of these markers with genetic and nongenetic diseases which differ in their ethnic distribution. Moreover, such data should also be of considerable historical and theoretical value in suggesting or even delineating relationships among the various Jewish communities, as well as between each of these and their respective 'host' population. The Jewish Libyan community has been known to harbor several diseases in unusually high frequencies, such as familial Mediterranean fever (FMF) (Adam, 1973), cystinuria (Weinberger et al., 1974), and the probably nongenetic disorder Creutzfeldt-Jakob disease (Kahanah et al., 1974). Therefore, a comprehensive study of Libyan Jews' gene pool seemed desirable. Recently a report on some genetic markers in Libyan non-Jews was published (Walter et al., 1975). A comparison of these data with our results may aid in assessing the extent to which there has been admixture between Jews and non-Jews in Libya. The purpose of this paper therefore, is to present the frequencies of certain genetic markers obtained on the Libyan Jews and compare these with those reported for Libya in general.

320

B. Bonn6-Tamir et al.

Historical Background In his account of travels in North Africa, Slouschz (1927) states that there have been Jews in the town of Tripoli from the earliest times, perhaps from the period of Phoenician colonization. After the destruction of the second temple in Jerusalem (70 A.D.) the number of Jews in North Africa and in Libya increased steadily as a result of migrations from Palestine, as well as from the proselyte movements (Hirshberg, 1960). According to literary documents, Roman road maps and various archeologic findings and inscriptions, several towns along the coast and inland were populated mainly by Jews (Hirshberg, 1969). The Moslem conquest of North Africa in the 7th century resulted in additional waves of Jews into Libya from Arabia and Syria, who brought with them the Arabic language (Zuaretz, 1960). There are also reports that during the l l t h century a large Jewish community flourished in the town of Tripoli (Zuaretz, 1960). During the expulsion from Spain (1492--1497) many Jews left for the African north coas~ and settled, among other Maghreb countries, in Libya. These settlers were later joined (during the 17th--18th centuries) by Jews from Leghorn (Italy), who themselves were descendants of Spanish exiles. A detailed demographic study of Libyan Jews during the 19th century was made by Goldberg (1971). He found a constant population growth of Tripolitanian Jewry (Western Libya) between 1853 and 1948 from 10000 Jews to about 29000, and of the latter 21000 lived in the city of Tripoli. Goldberg assumes that among factors contributing to the population growth of, specifically, the Jewish community of Tripoli itself, are natural increase and migration from the rural areas, since "there is no evidence of large-scale-in-migration to Tripoli from areas outside Tripolitania" (Goldberg, 1971, p. 255). A mass migration of Tripolitanian Jewry to Israel began in 1949; some 30000, almost the entire Jewish community, have left Libya since then.

M a t e r i a l and M e t h o d s During 1973/1974, weekly visits to settlements in Israel with predominantly Libyan inhabitants were made and 196 individuals were interviewed and examined. Efforts were made to include Jews who represented proportionately the entire Libyan Jewish population, rather than settlers of selected villages in which certain families or small isolated communities from Libya remained intact. In this sample, which comprises about 80% from the town of Tripoli, a total of 107 different Libyan families are represented. Blood specimens from each participant placed in two separate tubes were obtained and brought back to the laboratory on day of collection. Tests for red-cell antigens were performed either immediately or on the following day. Hemolysates were prepared, stored, and tested for the variants of red-cell enzyme polymorphisms by the standard starch gel electrophoretic methods described by Giblett (1970). A second tube was shipped by air to the Genetics Laboratory in Oxford for HLA typing and analysis (Bonn6-Tamir et al., 1977a).

The red-cell antigen typing included the following groups: AB0, MNS, Rh, P, Kell, Duffy, Kidd and Lutheran. Red-cell enzymes: acid phosphatase, phosphoglucomutase, adenylate kinase, adenosine deaminase, 6-phosphogluconate dehydrogenase, glutamic pyruvic transaminase, peptidase, lactic dehydrogenase, phosphohexose isomerase. Serum proteins: haptoglobins and transferrins. Several related individuals were identified in the sample. However, the gene frequency analysis is based only on randomly chosen individuals. Thus, the results are of a total of 148 random Libyan Jews.

Genetic Markers in Libyan Jews

321

Results P h e n o t y p e s a n d gene frequencies o f the v a r i o u s p o l y m o r p h i c systems investigated are p r e s e n t e d in Tables 1--12. In all these systems, o b s e r v e d frequencies are in a g r e e m e n t with t h o s e expected on the basis o f H a r d y - W e i n b e r g p r o p o r t i o n s . T a b l e 5 s u m m a r i z e s p h e n o t y p e s a n d frequencies in f o u r b l o o d - g r o u p systems in wh i ch only one a n t i s e r u m was used to d e t e r m i n e presence or absence o f the antigen. Since no a n t i - K i d d b was available, an excess o f h o m o z y g o t e s as r e p o r t e d by W a l t e r et al., (1975) c o u ld n o t be ascertained. N o rare types or variants were e n c o u n t e r e d in any system except P G M . O n e case o f either partial or t o t al

Table 1. AB0 phenotype and gene frequencies Phenotype

Observed

%

Expected

A1 Az A1B A2B B 0

68 7 11 -18 44

45.95 4.73 7.43 -12.16 29.73

69.15 5.92 9.66 1.08 18.25 43.96

Total

148

100.00

148.02

Gene ~equencies: Pl = 0.3162 P2 = 0.0355 q = 0.1033 r = 0.5450

Table 2. MNSs phenotype and gene frequencies Phenotype

Observed

%

Expected

MMS MMss MNS MNss NNS NNss

35 13 42 32 10 16

23.65 8.78 28.38 21.62 6.76 10.81

36.24 12.59 43.89 28.49 10.71 16.10

Total

148

100.00

148.02

Gene frequencies: MS = 0.2826 Ms = 0.2917 NS = 0.0958 Ns = 0.3299

322

B. Bonn6-Tamir et al.

Table 3. Rh phenotype and gene frequencies Phenotype

Observed

%

Expected

ccddee Ccddee ccDee CcDee CCDee ccDEe CcDEe CCddee ccDEE

20 3 7 61 43 10 4 ---

13.51 2.03 4.73 41.22 29.05 6.76 2.70 ---

20.51 2.92 7.16 63.68 39.96 6.05 7.28 0.10 0.33

148

100.00

147.99

Total

Gene frequencies: cde =0.3723 Cde = 0.0265 CDe = 0.4938 c D e = 0.0601 CDE = 0.0000 cDE = 0.0473

Table 4. Duffy phenotype and gene frequencies Phenotype

Observed

%

Expected

Fy(a-b+) Fy(a+b+) Fy(a+b-)

51 62 35

34.46 41.89 23.65

45.44 73.16 29.44

148

i00.00

148.04

Total

Gene frequencies: Fya = 0.4460 Fyb = 0.5541

deficiency of the p h o s p h o g l u c o m u t a s e 1 gene was discovered in a n elderly L i b y a n male. No zones c o r r e s p o n d i n g to isozymes a, b, c, or d were visible in a starch gel electrophoretic assay, thus i n d i c a t i n g a PGM1 0 phenotype. His son was f o u n d to have the p a t t e r n of P G M I 2. U n f o r t u n a t e l y , a b l o o d specimen from the m o t h e r was u n a v a i l a b l e . Q u a n t i t a t i v e enzymatic assays of this p e r s o n ' s blood, a n d possibly of the b l o o d of other family members, are currently p l a n n e d in an a t t e m p t to verify a n d explain this p h e n o m e n o n . N o v a r i a n t forms were observed in 148 subjects tested for the following polym o r p h i s m s : L D H , PGM2, PHI, P E P A, PEP B, a n d transferrins. All were of the same c o m m o n type.

Table 5. Lutheran, P, Kell, and Kidd phenotypes and gene frequencies Phenotype

Observed

%

Gene frequencies

Lu a+

14

10.77

La a -

116

89.23

Total

130

100.00

P+

108

72.97

P-

40

27.03

148

100.00

Total

Lu a = 0.0554

P~ =

0.4801

K+

9

6.08

K = 0.0309

K-

139

93.92

k = 0.9691

Total

148

100.00

JK"+

92

62.16

Jk a -

56

37.84

Total

148

100.00

Jk a = 0.3849

Table 6. Haptoglobin phenotype and gene frequencies Phenotype

Observed

%

Expected

Hp 1-1

8

5.41

8.52

Hp 1-2

55

37.16

53.98

Hp 2-2

85

57.43

85.51

148

100.00

148.01

Total

Gene frequencies: Hp I = 0.2399 Hp 2 = 0.7601 Table 7. Red-cell A.P. phenotype and gene frequencies Phenotype

Observed

%

Expected

AP A

12

8.11

10.29

AP AB

52

35.14

55.88

AP B

78

52.70

75.91

AP BC

4

2.70

4.31

AP AC

2

1.35

AP

C

Total

--

148

Gene frequencies: AP A = 0.2636 AP B = 0.7162 A P e = 0.0203

-100.00

1.58 0.06 148.03

324

B. Bonn&Tamir et al.

Table 8. Phosphoglucomutase phenotype and gene frequencies Phenotype

Observed

%

Expected

P G M 1-1

93

62.84

91.55

P G M 1-2

46

31.08

48.94

P G M 2-2

8

5.41

PGM 0

1

0.68

148

100.00

Total

6.54 -147.03

Gene frequencies: PGMI = 0.7892 P G M 2 = 0.2109

Table 9. Adenylate kinase phenotype and gene frequencies Phenotype

Observed

%

Expected

AK 1-1

141

95.27

141.10

AK 1-2

7

4.73

AK 2-2

--

Total

148

-100.00

6.85 0.09 148.04

Gene frequencies: AK 1 = 0.9764 AK 2 = 0.0237

Table 10. Adenosine deaminase phenotype and gene frequencies Phenotype

Observed

%

Expected

A D A 1-1 A D A 1-2

135 13

91.22 8.78

135.29 12.49

A D A 2-2

--

--

Total

148

100.00

0.28 147.99

Gene frequencies: A D A 1 = 0.9561 A D A 2 = 0.0439

Discussion T h e f r e q u e n c i e s o f t h e v a r i o u s b l o o d m a r k e r s i n L i b y a n J e w s fall w i t h i n t h e r a n g e of other Caucasian populations in which these genetic markers were investigated. Yet they do not however seem to resemble closely any one particular population;

Genetic Markers in Libyan Jews

325

Table 11.6-Phosphogluconate phenotype and gene frequencies Phenotype

Observed

%

Expected

6PG A 6PG AB 6PG B

122 24 2

82.43 16.22 1.35

121.32 25.35 1.32

Total

148

100.00

147.99

Gene frequencies: pgh= 0.9054 pgR= 0.0946

Table 12. Glutamic pyruvic transaminase. Phenotype and gene frequencies Phenotype

Observed

%

Expected

GPT 1-1 GPT 1-2 GPT 2-2

42 67 18

33.07 52.76 14.17

44.88 61.23 20.88

127

100.00

126.99

Total

Gene frequencies: GPT 1= 0.5945 GPT2 = 0.4055

rather, they exhibit a gene pool characteristic to themselves, i.e., high frequency of A in the AB0 group, low frequency o f c D E in the Rh system (see WorldPopulations in: Mourant, 1976). ,The haptoglobins in our sample are another system with a rather unique frequency of only 24% of the Hpa gene (for comparisons see: Wing-Patai, 1974). The question of similarities of the Libyan Jews to Europeans and other Jewish populations will be dealt with in a later overall analysis when estimates of genetic distances between various Jewish communities will be described from a comprehensive investigation in progress. In the present paper we shall focus on comparisons with the data reported for Tripolitanian non-Jews (Walter et al., 1975). When our results are compared with those cited by Walter et al. (1975) differences in phenotypes and gene frequencies are rather prominent in almost all systems. In seven groups a significant X2 value was obtained for these differences, as indicated in Table 13. Whether the people studied by us are descendants of the 'old-time' Libyan communities described in the historical section, or whether they descended from Spanish Jews driven out of Spain in the 15th century, little if any admixture

326

B. Bonn6-Tamir et al.

Table 13. A comparison of seven systems in Libyan Jews and non-Jews Libyan Jews (this study)

No. 148

Libyan non-Jews (Walter et al., 1975) No. 165

p2 q r

0.316 0.036 0.103 0.545

0.147 0.078 0.132 0.643

22.09

P < 0.005

CDE CDe Cde cDE cDe cde cdE

0 0.494 0.027 0.047 0.060 0.372 0

0 0.412 0.008 0.133 0.110 0.329 0.008

20.00

P < 0.005

Fya Fyb Fy~

0.446 0.554 0

0.390 0.299 0.311

29.20

P < 0.005

Lutheran

Lua+ Lua-

0.055 0.945

0.006 0.994

25.23

P < 0.005

P

P+ P-

0.480 0.520

0.578 0.422

4.5

P < 0.05

Hp

Hp 1 Hp 2

0.239 0.761

0.438 0.562

25.23

P < 0.005

Acid phosphatase

Ap a Ap b Apc

0.264 0.716 0.020

0.140 0.845 0.015

15.89

P < 0.005

AB0

Rh

Fy

p1

Significant differences Value of Z2

Probability

b e t w e e n Jews a n d n o n - J e w s in L i b y a in the last c e n t u r y seems likely in the light o f the dissimilarities n o t e d in m o r e t h a n one genetic m a r k e r . M o r e o v e r , in the d a t a o f W a l t e r et al. (1975) there is evidence o f some n e g r o i d a d m i x t u r e , s h o w n b y the presence o f A f r i c a n genes such as F y c in the D u f f y system a n d elevated frequencies in those systems in which the highest frequencies are f o u n d a m o n g A f r i c a n p o p u l a t i o n s , genes such as Hp~ a n d A p b. There is no evidence o f A f r i c a n genes in the L i b y a n Jews: n o t a single type o f F y ( a - b - ) o c c u r r e d in o u r sample; the f r e q u e n c y o f c D e in the R h is also n o t very high (6%, as c o m p a r e d to a b o u t 4% in C a u c a s o i d s , b u t 11% in n o n - J e w i s h Libyans). The frequencies o f K i d d a a n d h a p t o g l o b i n 1 are lower t h a n q u o t e d for m o s t Caucasoid populations. A d m i t t e d l y , o u r s a m p l e o f 148 individuals is small. But similar b l o o d g r o u p frequencies a n d in the s a m e d i r e c t i o n were also o b t a i n e d b y two o t h e r Israeli

Genetic Markers in Libyan Jews

327

investigators on two independent samples of Libyan Jews (Levin, personal communication; Bar-Shani, personal communication). This supporting evidence, as well as the lack of a negroid component in their samples, would seem to indicate that the results here presented are valid for Libyan Jews in general. The G P T system has not been determined in the Libyan non-Jews, but the frequencies obtained for the Libyan Jews (Table 12) are close to Caucasoid populations and show no similarity to those reported for African populations (Seth, 1974). Two additional points of interest are worth mentioning in this context, albeit not directly relevant to the comparison within Libya: 1. In a study of the H L A polymorphism, Libyan Jews were found to be very close to the Armenians (Bonnr-Tamir et al., 1977b). The late Dr. Sheba suggested, on the basis of F M F frequencies and distribution, a relationship between these two communities (Sheba, 1968). High frequency of the A antigen in the AB0, of cde in Rh, and of Fy" in Duffy, as found in Libyan Jews (Tables 1, 3 and 4), were also discovered in the Armenians (Bonnr-Tamir, 1972, unpublished). 2. Often, Jews from the four Maghreb countries in North Africa are considered as a single whole in discussions of genetic characteristics. Our own studies of blood markers (Bonnr-Tamir et al., 1977b) and others on the distribution of various genetic diseases (Ben-Bassat, 1969; Shani, 1970; Adam, 1973), point to variations in frequencies which suggest that even in the same geographic areas the different Jewish communities maintained a rather high degree of genetic isolation. In the literature one encounters statements that blood group data show that Jews of any given area tend to resemble the non-Jews of that area, or that genetic similarities between Jews and non-Jews of the same region are probably due to interbreeding, coupled with environmental effects (Patai, 1975). We would like to suggest, on the basis of the data presented, that the question of genetic similarities between Jews and non-Jews of the same region must be carefully examined in each instance before general statements on Jewish mixture with surrounding populations are made.

Acknowledgments. We are grateful to Dr. R. Konfino, Head Physician of the Labour-Sick Fund in Jaffa, and his staff in the clinics of Bat-Yam and Hazav for permission, arrangements, and valuable help in the field work. This study was supported by a grant from the American Joint Distribution Committee and in part by a grant from the Chief Scientific Office of the Ministry of Health (No. 219-Dr. B. Bonnr-Tamir).

References Adam, A.: Genetic diseases among Jews. Israel J. reed. Sci. 9, 1383--1392 (1973) Ben-Bassatt, Is., Feinstein, A., Ramot, B.: Selective vitamin B~2malabsorption with proteinuria in Israel: Clinical and genetic aspects. Israel J. reed. Sci. 5, 62--68 (1969) Bonn6-Tamir, B., Bodmer, J. G., Modai, J.: HLA polymorphism in Israel. VI Nort African Jews from Lybia. Tissue Antigens (in press, 1977a) Bonnr-Tamir, B., Bodmer, J. G., Bodmer, W. F., Pickford, P., Gazit, E., Brautbar, C., Nevo, S., Zamir, R.: HLA polymorphism in Israel. IX An overall comparative analysis. Tissue Antigens (in press, 1977b)

328

B. Bonn6-Tamir et al.

Giblett, E. R.: Genetic markers in human blood. Oxford-Edinburgh: Blackwell 1970 Goldberg, H.: Ecologic and demographic aspects of rural tripolitanian Jewry: 1853--1949. Int. J. Middle East Stud. 2, 245--265 (1971) Heller, H.: Ethnic differences in the prevalence of FMF and their historical and anthropological meaning from the viewpoint of population genetics (in Hebrew). Tel-Hashomer Hosp. 8, 23 (1968) Hirshberg, Ch. Z.: North African Jewry (in Hebrew). Chief Educational Office Israel 1960 Hirshberg, Ch. Z.: Libya-Jews. In: Encyclopedia Hebraica (in Hebrew) 21,281. Encyclopedia Publishing Co. Ltd. Israel 1969 Kahana, E., Alter, M., Braham, J., Dov Sofer: Creutzfeld-Jakob Diseases, focus among Libyan Jews in Israel. Science 183, 90--91 (1974) Mourant, E. A., Kopec, A. C., Domaniewska-Sobczak, K.: The distribution of the human blood groups. London: Oxford Univ. Press 1976 Patai, R., Patai-Wing, J.: The myth of the Jewish race. New York: Charles Scribner 1975 Seth, Swadesh: Population genetics of soluble glutamic-pyruvic-transaminasein North Germans (Liabeck). Humangenetik 23, 223--226 (1974) Shani, M., Seligsohn, V., Gilon, E., Sheba, C., Adam, A.: Dubin-Johnson syndrome in Israel. I. Clinical laboratory and genetic aspects of 101 cases. Quart. J. Med. 39, 549 (1970) Sheba, Ch.: The genetics of Israel's tribes (in Hebrew). Madah 13, 94--99 (1968) Slouchz, N.: Travels in North Africa, p. 11. Philadelphia Jewish publication Society of America, 1927 Walter, H., Arndt-Hanser, A., Raffa, M. A., Gumbel, B.: On the distribution of some genetic markers in Lybia. Humangenetik 27, 129--136 (1975) Weinberger, A., Sperling, O., Rabinovitz, M., Brosh, S., Adam, A., De Vries, A.: High frequency of cystinuria among Jews of Libyan origin. Hum. Hered. 24, 568--572 (1974) Wing-Patai, J.: Blood protein polymorphisms in Jewish populations. Hum. Hered. 24, 323--344 (1974) Zuaretz, F.: Libyan Jews (ed. in Hebrew). Council of Libyan Communities in Israel. Tel-Aviv 1960

Received March 16, 1977

Genetic markers in Libyan Jews.

Hum. Genet. 37,319--328 (1977) © by Springer-Verlag 1977 Genetic Markers in Libyan Jews Batsheva Bonn6-Tamir, Sarah Ashbel, and Jehudit Modai Departm...
419KB Sizes 0 Downloads 0 Views