Allele Frequency and Genotype Distribution of 9 SNPs in the Kazakh Population

Abstract

Background: Determining the allelic variants of xenobiotic biotransformation genes is important, especially for prescribing personalised drugs. Knowledge of the allele distribution in different populations may be considered when selecting the preferred medication regimen. The frequency of CYP2C9, VKORC1, CYP4F2, GGCX, CYP2D6 and CYP1A2 genes has been studied in many populations, but the populations in Central Asia have not yet been investigated. Methods and materials: Using real-time PCR and direct sequencing-based methods, the current study assessed the frequencies of 9 polymorphisms of genes encoding enzymes involved in drug metabolism in 450 healthy individuals from different regions of Kazakhstan and 575 healthy individuals from the West-Siberian region of Russia. Results: The allele frequencies in the Kazakh population were determined for CYP2C9*2 (0.02), CYP2C9*3 (0.03), VKORC1 c. 173+1369G>C, VKORC1 c. 173+1000C>T (0.72, СYP4F2 (0.31), GGCX (0.04), CYP2D6*4 (0.07), CYP2D6*3 (0.01) and CYP1A2*1F (0.35). All alleles were in Hardy–Weinberg equilibrium (p > 0.05). The allele frequencies in the Russian population were as follows: CYP2C9*2, 0.08; CYP2C9*3, 0.08; VKORC1 (c. 173+1000C>T), 0.40; VKORC1 (c. 173+1369G>C), 0.41; СYP4F2 (c. 1297G>A), 0.24; GGCX (c. 1913+45G>C), 0.08; CYP2D6*3, 0.15; CYP2D6*4, 0.22; and CYP1A2*1F (c. -9-154C>A), 0.31. All alleles were in Hardy–Weinberg equilibrium (p>0.05), except GGCX (p=0.04). Conclusion: The Kazakh population allele frequency was between the Caucasian and Asian populations for nearly all of the studied gene allele variants.