O riginal Paper
Hum Hered 1992;42:264-268
J.L.B. Catiroa E. Parraa A. Gremoh J.M. Ruiz de ¡a Cuestab
Distribution of F13A Phenotypes in Spain: A Particularly High Frequency of the F13A*2 Allele
Departamento de Antropoloxía, Facultado de Bioloxía, Santiago de Compostela; Departamento de Medicina Legal, Facultad de Medicina, Universidad Complutense, Madrid, Spain
Key Words
Abstract
Coagulation Factor XIIIA Gene frequency Genetic marker Genetic polymorphism Plasma proteins Population genetics Spanish populations
The distribution of the phenotypes for coagulation factor XIIIA subunit (F13A) of autochthonous individuals from the following five Spanish populations was studied: Galicia, Cas tilla-León, Castilla-La Mancha, Extremadura and Western Andalusia. The frequency values obtained for F13A*2 ranged from 0.248 to 0.311. To date, these values are the highest re corded in the world.
Coagulation circulation factor XIIIA (F13A) corresponds to a tetrameric form com posed of 2 A and 2 B monomers. The B sub units probably represent the carrier fraction, whereas the A subunits catalyze the formation of y-glutamyl-e-lysil cross-links between the fibrin monomers [1], Application of agarose thin layer electro phoresis allowed Board [2] to report the exis tence of F13A polymorphism, using its trans glutaminase activity as a strategy for specific detection. This polymorphism is due to the oc currence of two autosomal codominant com
mon alleles (F13A*1 and F13A*2). Subsequent investigations have shown the existence of other rare variants and subtypes [3,4]. Reports on the distribution of F13A types in the major racial groups suggest that this is a valuable system in population genetic studies. To date, the literature regarding European populations is scarce, therefore this paper aims to evaluate five Spanish populations, in order to contribute to a better understanding of F13A allele distribution in this geographical location.
J.L.B. Caeiro Departamento de Antropoloxía Facultadc de Bioloxía Universidade dc Santiago dc Compostela Galicia (Spain)
© 1992 S. Kargcr AG, Basel 0001-5652/92/ 0424-0264 $ 2.75/0
Downloaded by: King's College London 137.73.144.138 - 1/13/2019 3:27:20 AM
Introduction
Fig. 1. F13A phenotypes after polyacrylamide gel isoelectric fo cusing (pH 3.5-10) and immunofixation. 1,3, 7.8.13 = FI3A 1-1; 2.4,6, 10,12,14 = FI3A 2-1; 5 . 9, 11 = F13A 2-2.
Only unrelated autochthonous (at least two gener ations) individuals representative of their respective regions have been studied. Blood samples were ob tained by vein puncture and treated with EDTA-Na, (10%, w/v) (0.05 ml/ml blood) as anticoagulant. Plasma was aliquoted and stored at —20 °C no longer than 3 years before analysis. Phenotyping of F13A was performed by isoelectric focusing on 0.5 x 230 x 115 mm polyacrylamide gels ac cording to the following concentrations: T = 5, C = 3, AmpholineK (Pharmacia-LKB. Uppsala. Sweden) pH 3.5-10 at 2% (w/v). Photopolymerization took place un der 360 nm light for 25-30 min using riboflavin at 0.00075% (w/v). 1 M phosphoric acid and 1 N sodium hydroxide were used as anolyte and catholyte, respec tively. Plasma samples were applied by soaking small pieces of 0.8 x 0.5 cm Whatman No. 1 paper. Focusing was conducted at a maximum of 1.200 V. 20 mA and 8 W. The pieces of paper were removed after 45 min, and focusing was prolonged for a further 45 min. Diluted anti-FXIHA (Behringwerkc, Marburg. FRG) 1:3 (v/v) in saline was uniformly spread on the gel surface (at 4-6 cm from the anode). After incuba
tion at 37 °C in a moist chamber for 2 h, the gel was ex tensively washed overnight in saline. Finally, visualiza tion of immunoprccipitatcs was achieved by means of simplified silver staining [5] with minor modifications.
Results and Discussion
Figure 1 shows the phenotype patterns of F13A under the above-mentioned conditions. The high sensitivity of silver staining enables an adequate detection of immunoprecipitates even from minimal amounts of sample (0.5 pi of plasma is sufficient for analysis). Table 1summarizes the distribution of phe notype and allele frequencies of F13A among the populations referred to in figure 2. No rare variants were observed in either case. The dis tribution of phenotype values observed in this study is in agreement with expectations as suming the Hardy-Weinberg equilibrium.
265
Downloaded by: King's College London 137.73.144.138 - 1/13/2019 3:27:20 AM
Materials and Methods
Table 1. Phenotype distribution and allele frequencies of FI3A
Population
Galicia Castilla-Lcon Castilla-La Mancha Extremadura Western Andalusia
2
F13A*2 allele frequency ±s.e.
X"hw
p (1 d.f.)
32 (32.81) 19(17.44)
0.2476 ±0.013 0.2931 ±0.022
0.0306 0.2791
0.95-0.98 0.5-0.7
105 (101.98) 47 (48.88)
21 (22.51) 12 (11.05)
0.3062 ±0.021 0.3114 ±0.031
0.2104 0.1711
0.5-0.7 Ü.5-0.7
67 (69.63)
15 (13.67)
0.2819 ±0.024
0.2486
0.5-0.7
Number of individuals
FI 3A phenotypes 1-1
2-1
2-2
527 203
298 (296.83) 103 (101.44)
197 (197.36) 81 (84.12)
240 114
114 (115.51) 55 (54.04)
172
90 (88.67)
Expected values are put in parenthesis.
266
It should be emphasized that particularly high F13A frequencies were found in the Ibe rian peninsula populations. In fact, these fre quencies are the highest recorded not only for the European, but also for the world popula tions so far examined. Frequencies observed in Galicia were somewhat lower than in the rest of the Spanish populations studied, and were similar to those reported for northern Portugal [6]. Moreover, both fall within the midrange between the Iberian populations studied, and those of northern and central Eu rope. Further European population studies are required in order to clarify the genetic meaning of this distribution of frequencies.
Caeiro/Parra/Gremo/Ruiz de la Cuesta
Distribution of F13A Phenotypes in Spain
Downloaded by: King's College London 137.73.144.138 - 1/13/2019 3:27:20 AM
In our study the F13A*2 frequencies ranged from 0.248 (Galicia) to 0.311 (Extre madura). Statistical comparison of F13A al lele frequencies between both extreme pop ulations reveals significant differences (x2= 3.963,0.02 < p
Hum Hered 1992;42:264-268
J.L.B. Catiroa E. Parraa A. Gremoh J.M. Ruiz de ¡a Cuestab
Distribution of F13A Phenotypes in Spain: A Particularly High Frequency of the F13A*2 Allele
Departamento de Antropoloxía, Facultado de Bioloxía, Santiago de Compostela; Departamento de Medicina Legal, Facultad de Medicina, Universidad Complutense, Madrid, Spain
Key Words
Abstract
Coagulation Factor XIIIA Gene frequency Genetic marker Genetic polymorphism Plasma proteins Population genetics Spanish populations
The distribution of the phenotypes for coagulation factor XIIIA subunit (F13A) of autochthonous individuals from the following five Spanish populations was studied: Galicia, Cas tilla-León, Castilla-La Mancha, Extremadura and Western Andalusia. The frequency values obtained for F13A*2 ranged from 0.248 to 0.311. To date, these values are the highest re corded in the world.
Coagulation circulation factor XIIIA (F13A) corresponds to a tetrameric form com posed of 2 A and 2 B monomers. The B sub units probably represent the carrier fraction, whereas the A subunits catalyze the formation of y-glutamyl-e-lysil cross-links between the fibrin monomers [1], Application of agarose thin layer electro phoresis allowed Board [2] to report the exis tence of F13A polymorphism, using its trans glutaminase activity as a strategy for specific detection. This polymorphism is due to the oc currence of two autosomal codominant com
mon alleles (F13A*1 and F13A*2). Subsequent investigations have shown the existence of other rare variants and subtypes [3,4]. Reports on the distribution of F13A types in the major racial groups suggest that this is a valuable system in population genetic studies. To date, the literature regarding European populations is scarce, therefore this paper aims to evaluate five Spanish populations, in order to contribute to a better understanding of F13A allele distribution in this geographical location.
J.L.B. Caeiro Departamento de Antropoloxía Facultadc de Bioloxía Universidade dc Santiago dc Compostela Galicia (Spain)
© 1992 S. Kargcr AG, Basel 0001-5652/92/ 0424-0264 $ 2.75/0
Downloaded by: King's College London 137.73.144.138 - 1/13/2019 3:27:20 AM
Introduction
Fig. 1. F13A phenotypes after polyacrylamide gel isoelectric fo cusing (pH 3.5-10) and immunofixation. 1,3, 7.8.13 = FI3A 1-1; 2.4,6, 10,12,14 = FI3A 2-1; 5 . 9, 11 = F13A 2-2.
Only unrelated autochthonous (at least two gener ations) individuals representative of their respective regions have been studied. Blood samples were ob tained by vein puncture and treated with EDTA-Na, (10%, w/v) (0.05 ml/ml blood) as anticoagulant. Plasma was aliquoted and stored at —20 °C no longer than 3 years before analysis. Phenotyping of F13A was performed by isoelectric focusing on 0.5 x 230 x 115 mm polyacrylamide gels ac cording to the following concentrations: T = 5, C = 3, AmpholineK (Pharmacia-LKB. Uppsala. Sweden) pH 3.5-10 at 2% (w/v). Photopolymerization took place un der 360 nm light for 25-30 min using riboflavin at 0.00075% (w/v). 1 M phosphoric acid and 1 N sodium hydroxide were used as anolyte and catholyte, respec tively. Plasma samples were applied by soaking small pieces of 0.8 x 0.5 cm Whatman No. 1 paper. Focusing was conducted at a maximum of 1.200 V. 20 mA and 8 W. The pieces of paper were removed after 45 min, and focusing was prolonged for a further 45 min. Diluted anti-FXIHA (Behringwerkc, Marburg. FRG) 1:3 (v/v) in saline was uniformly spread on the gel surface (at 4-6 cm from the anode). After incuba
tion at 37 °C in a moist chamber for 2 h, the gel was ex tensively washed overnight in saline. Finally, visualiza tion of immunoprccipitatcs was achieved by means of simplified silver staining [5] with minor modifications.
Results and Discussion
Figure 1 shows the phenotype patterns of F13A under the above-mentioned conditions. The high sensitivity of silver staining enables an adequate detection of immunoprecipitates even from minimal amounts of sample (0.5 pi of plasma is sufficient for analysis). Table 1summarizes the distribution of phe notype and allele frequencies of F13A among the populations referred to in figure 2. No rare variants were observed in either case. The dis tribution of phenotype values observed in this study is in agreement with expectations as suming the Hardy-Weinberg equilibrium.
265
Downloaded by: King's College London 137.73.144.138 - 1/13/2019 3:27:20 AM
Materials and Methods
Table 1. Phenotype distribution and allele frequencies of FI3A
Population
Galicia Castilla-Lcon Castilla-La Mancha Extremadura Western Andalusia
2
F13A*2 allele frequency ±s.e.
X"hw
p (1 d.f.)
32 (32.81) 19(17.44)
0.2476 ±0.013 0.2931 ±0.022
0.0306 0.2791
0.95-0.98 0.5-0.7
105 (101.98) 47 (48.88)
21 (22.51) 12 (11.05)
0.3062 ±0.021 0.3114 ±0.031
0.2104 0.1711
0.5-0.7 Ü.5-0.7
67 (69.63)
15 (13.67)
0.2819 ±0.024
0.2486
0.5-0.7
Number of individuals
FI 3A phenotypes 1-1
2-1
2-2
527 203
298 (296.83) 103 (101.44)
197 (197.36) 81 (84.12)
240 114
114 (115.51) 55 (54.04)
172
90 (88.67)
Expected values are put in parenthesis.
266
It should be emphasized that particularly high F13A frequencies were found in the Ibe rian peninsula populations. In fact, these fre quencies are the highest recorded not only for the European, but also for the world popula tions so far examined. Frequencies observed in Galicia were somewhat lower than in the rest of the Spanish populations studied, and were similar to those reported for northern Portugal [6]. Moreover, both fall within the midrange between the Iberian populations studied, and those of northern and central Eu rope. Further European population studies are required in order to clarify the genetic meaning of this distribution of frequencies.
Caeiro/Parra/Gremo/Ruiz de la Cuesta
Distribution of F13A Phenotypes in Spain
Downloaded by: King's College London 137.73.144.138 - 1/13/2019 3:27:20 AM
In our study the F13A*2 frequencies ranged from 0.248 (Galicia) to 0.311 (Extre madura). Statistical comparison of F13A al lele frequencies between both extreme pop ulations reveals significant differences (x2= 3.963,0.02 < p
