Distribution of CYP2C19☆2 and CYP2C19☆3 polymorphisms in Venezuelan populations with different admixture

Background: The conquest and colonization of Venezuela generated very heterogeneous populations as a product of admixture; for this reason, the distribution of polymorphisms of the CYP2C19 gene was studied in various Venezuelan populations. Methods: Two hundred and eighty-one individuals, from three Venezuelan populations with different admixtures, were genotyped for CYP2C19(star)2 and CYP2C19(star)3 polymorphisms. Differences between groups were analysed using a chi-square test of heterogeneity and association of allele frequencies with the level of genetic admixture was performed using a principal component analysis (PCA). No significant differences in distribution of alleles, genotypes and phenotypes were found between the populations studied. Results: In Venezuela, high frequencies of the alleles CYP2C19(star)2 and CYP2C19(star)3 were found compared with Europeans, Africans and Latin Americans, similar to those reported in Asia. PCA analysis suggested that the presence of alleles CYP2C19(star)2 and CYP2C19(star)3 is associated with the indigenous component in the Venezuelan populations studied. Conclusions: Future studies are needed to confirm this association. High frequencies of intermediate metabolizers (20-38%) and of poor metabolizers (2-7%) were observed, similar to values reported for Asians and higher than those reported for South Americans. This is the first study evaluating CYP2C19 polymorphisms in the Venezuelan general population.