The frequencies of mutated alleles of CYP2D6 gene in a Turkish population

Allele and genotype frequency distribution of CYP2D6*3, *4, *5, *6 and *10 variants were analyzed in blood samples of 100 unrelated healthy individuals by Real-Time PCR. The allele frequencies of CYP2D6*3(A2549del), *4(G1846A), *6(T1707del) and *10(C100T) were 1%, 10%, 2.5% and 14.5% respectively, while allele frequency of CYP2D6*5 was 3% of the subjects tested. Extensive, poor and intermediate metabolizer (EM, PM, IM) genotype frequencies were 63%, 4% and 12%, respectively. CYP2D6 gene duplication was 4%. Our results show that the frequencies of the mutated alleles of CYP2D6 in Turkish populations are similar to some European populations. 4% of Turkish people who have two nonfunctional defective allele are a high risk group and 12.5% of Turkish people who have two decreased functional defective allele or one normal and one non functional defective allele were also in the risk group. Findings of this study demonstrate the importance of genetic variation in drug intoxicants.