Frequency Evaluation of GSTM1 and GSTT1 Null Genotypes in a Healthy Population in Mazandaran Province

Background and Glutathion S-transferase (GSTs) are a family of detoxification phase II enzymes that catalyze the conjugation of carcinogenic and cytotoxic componds with glutathion. GSTs are polymorphic and deletion of GSTM1 and GSTT1 polymorphism is caused by lack of enzyme production that lead to loss of antioxidant activity. In this study, we examined the frequency of GSTM1 and GSTT1 polymorphisms in a healthy population in Mazandaran province. In this experimental study, 250 non-relative healthy subjects in Mazandaran province enrolled. They were residing in Sari and attended Sari Blood Transfusion Center for blood donation. A total of 5 ml peripheral blood was taken from individuals. Genomic DNA was extracted using DNGTM Plus Blood DNA kit. The Multiplex- PCR method was used for the detection of genotypes in each subject. The subjects consisted of 210 men (84%) and 40 women (16%).The frequencies of the GSTM1 and GSTT1-null genotypes were 54 and 30%, respectively. For GSTM1 null genotype, the frequencies in women and men were 60% and 52.85%, respectively. While the frequencies of GSTT1 null genotype in women and men were 42.5% and 27.6%, respectively. In both regions, the frequency of null genotype was significantly higher in women (p<0.05). The genotype frequencies of null GSTM1 and GSTT1 were found to be relatively high in Mazandaran province and this could possibly have a role in increasing the susceptibility to some cancers.