Detecting the OPRK1 rs963549 and rs997917 Polymorphisms by Novel PCR-RFLP Methods and Determining Their Genotype/Allele Frequencies in a Turkish Population

Opioid receptor kappa (KOR) is one of three endogenous opioid receptors which has critical roles in rewarding systems by promoting anti-reward effects and causes dysphoria and relapse. KOR is encoded by the OPRK1 gene and the polymorphisms of OPRK1 gene have been reported to be associated with various diseases. OPRK1 rs963549 and rs997917 are two polymorphisms of the OPRK1 gene. They are shown to have potential to affect addiction and alter the response to pharmacotherapy leading to individual differences, therefore they are accepted as marker polymorphisms. Hence, in the current study, it is aimed to develop PCR-RFLP assays to genotype OPRK1 rs963549 and rs997917 polymorphisms. The PCR-RFLP methods were developed for the detection of OPRK1 rs963549 and rs997917 polymorphisms and were tested in 100 healthy Turkish controls. Allele frequencies of rs963549 in the Turkish population were 0.81 for allele C and 0.19 for allele T, and the genotype frequencies were 66% for CC, 31% for CT, and 3% for TT. For rs997917 polymorphism, 32% of studied subjects had TT genotype, 56 and 12% of them had TC and CC genotypes, respectively and allele frequencies were 0.60 for allele T and 0.40 for allele C. Novel PCR-RFLP methods were successfully developed for the detection of OPRK1 rs963549 and rs997917 polymorphisms, which could be preferred and easily applied in the laboratories aiming to genotype OPRK1 rs963549 and rs997917 polymorphisms. Moreover, obtained allele frequencies may provide a perspective to pharmacogenetics and individualized therapy.