Frequencies of two CYP۲C۱۹ defective alleles (CYP۲C۱۹*۲, and *۳) among Iranian population in Mazandaran Province

Background: Cytochrome P۴۵۰ ۲C۱۹ (CYP۲C۱۹) is a polymorphically expressed enzyme that shows marked interindividual and interethnic variation. CYP۲C۱۹*۲ and CYP۲C۱۹*۳ are the most frequently identified defective alleles in Orientals and Caucasian poor metabolizers (PM). The aim of this study was to investigate the frequencies of CYP۲C۱۹*۱, CYP۲C۱۹*۲ and CYP۲C۱۹*۳ alleles and CYP۲C۱۹ genotypes in the Mazandarani ethnic group among Iranian Population.  Materials and Methods: The study was conducted in ۱۰۳ unrelated healthy volunteers. DNA was extracted from leucocytes and analyzed by the PCR-RFLP protocol. The PCR product was digested with restriction enzymes (SmaI and BamH۱) and then separated electrophoretically using polyacrylamide gel.. Results: Of the alleles tested, CYP۲C۱۹*۱, and CYP۲C۱۹*۲, but not CYP۲C۱۹*۳, were detected. The frequencies for CYP۲C۱۹ alleles *۱, *۲, and *۳ were ۹۱%, ۹.۰%, and ۰.۰%, respectively. The frequencies of CYP۲C۱۹ genotypes *۱/*۱, *۱/*۲, *۱/*۳, *۲/*۲, *۲/*۳ and *۳/*۳ were ۸۴%, ۱۴%, ۰.۰%, ۲.۰%, and ۰.۰%, respectively. Conclusion: The result of the present study showed that the two inactive alleles of CYP۲C۱۹ accounted for ۹.۰% of CYP۲C۱۹ alleles in our sample versus ۸.۸ - ۴۰.۱% reported in other populations. The frequencies of the studied alleles resulted significant differences between our sample and African and Eastern Asian populations.