Summary
A polymorphism in the coagulation factor XIII gene (FXIII Val34Leu) has been recently
described to confer protection for arterial and venous thrombosis and to predispose
to intracerebral hemorrhage. At present it is known that FXIII Val34Leu is prevalent
in Caucasians, but information upon its distribution in different ethnic groups is
scarce. We investigated the prevalence of FXIIIVal34Leu in 450 unrelated subjects
of four ethnic groups: 97 Caucasians (Brazilians of European descent and Portuguese),
149 Blacks (Brazilians, and Africans from Cameroon, Zaire and Angola), 40 Asians (Japanese
descendents) and 164 Amerindians from South America. PCR amplification of exon 2 of
FXIII gene followed by MseI restriction-digestion was employed to define the genotypes. FXIIIVal34Leu was detected
in 44.3% of the Caucasians, in 28.9% of the Blacks, in 2.5% of the Asians and in 51.2%
of the Amerindians. These data confirm that FXIII Val34Leu is highly prevalent in
Caucasians and indicate that it is rarer in populations of African origin. The very
high frequency among Amerindians indicates that FXIII Val34Leu is not absent among
Asians, and since it has a very low prevalence in Japanese, a heterogeneity in its
distribution in Asia may be inferred. Taken together, our data showed that FXIII Val34Leu
exhibits a significant ethnic heterogeneity, a finding that is relevant for studies
relating this polymorphism with thrombotic and bleeding disorders.
Key words
Factor XIII - ethnic groups - thrombosis - risk factor
