Frequencies of four genetic polymorphisms in the CYP1A2 gene in Turkish population.

Cytochrome P450 (CYP) 1A2 gene is involved in the metabolic activation of several carcinogens and altered metabolization of some clinically used drugs. We aimed to investigate the distributions of genetic polymorphisms -3860 (G/A)(CYP1A21C) and -2467 (T/del)(CYP1A21D) in the 5'-flanking region and -739 (T/G)(CYP1A21E) and -163(C/A)(CYP1A21F) in the first intron of the CYP1A2 gene in 110 unrelated healthy Turkish volunteers by PCR-RFLP technique. The frequencies of each polymorphism in Turkish population were found as 0.04, 0.92, 0.01, 0.27 for CYP1A21C, CYP1A21D, CYP1A21E, CYP1A21F, respectively. Compared with other populations, CYP1A21D has been found to be significantly increased in Turkish population. On the other hand, in general, the frequencies of the other polymorphisms were concordant with those in the Egyptian and Caucasian populations, and were different from those in the Japanese, Chinese and Ethiopian populations. Our results suggest that due to increased frequency of CYP1A21D in Turkish population, functional significance of CYP1A21D should be evaluated. It might be screened to determine the relationship between CYP1A21D and CYP1A2 related drug metabolisms in associated groups.