Impact of null genotypes of GSTT1 and GSTM1 with uterine leiomyoma risk in Iranian population.

Aim: Few studies have investigated the role of the GSTM1 and GSTT1 genes in uterine leiomyoma. Therefore, in the current study the distribution of these genotypes in Iranian women and susceptibility to uterine leiomyoma was investigated.

Methods: Blood samples of 50 patients with uterine leiomyoma and 50 healthy individual controls were collected in this cross-sectional study. Genomic DNA was extracted, and subsequently GSTM1 and GSTT1 null genotypes were detected by the Gap-polymerase chain reaction method.

Results: A total of 42% of patients appeared to lack GSTM1 enzyme activity due to the presence of an extended deletion (GSTM1 0/0 genotype), compared with 18% in a control group (odds ratio [OR], 3.56; 95% confidence interval [CI], 1.35-9.37; P < 0.010). In addition, the prevalence of the GSTT1 null genotype in patients was higher than that in the control group (42% to 14%, P < 0.009). Also, it was shown that individuals with both null genotypes (-/-) had a 19.23-fold higher risk of developing the disease in comparison to people who showed both present genotypes (+/+). (P = 0.007; 95%CI, 2.20-167.41). Besides, it was observed that at least one null genotype increases the risk of myoma to 2.6 compared to the both present genotype (P-value < 0.03, 95%CI, 1.05-6.82).

Conclusion: To our knowledge, this is first significant correlation between risk of uterine leiomyoma and null GSTM1 and GSTT1 genotypes among Iranian patients. Our data support the involvement of GSTM1 and GSTT1 in uterine leiomyoma liability, and especially its role as a genetic factor in the occurrence of this disease.