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

ABSTRACT

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*2 and CYP2C19*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*2 and CYP2C19*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*2 and CYP2C19*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.