Serum testosterone in females exposed to natural sour gas with respect to polymorphisms of XRCC1, GSTM1, and GSTT1.

The present study was done to determine the modulation effect(s) of polymorphisms of XRCC1, GSTM1, and GSTT1 on concentration of serum testosterone in females exposed to natural sour gas. Also we examine whether chronic exposure to natural gas containing sulfur compounds act as natural selection force on XRCC1 polymorphisms. The present study was performed on 68 healthy unrelated female students living in polluted areas of MIS. Also for investigating the effect of natural selection on XRCC1 polymorphism, a study was performed on two groups of healthy individuals of MIS citizens. The first and second groups including 94 (age range 30-85 years) and 187 individuals (age range 5-20 years), respectively. First and second groups were born and were not born in contaminated areas of the MIS, respectively. There was no significant difference between genotypes of XRCC1 for concentration of serum testosterone. Although GSTT1-null genotype had higher level of serum testosterone in comparison with the present genotype (t=2.392, df=66, P=0.023), a borderline difference between genotypes of GSTM1 for serum testosterone was observed (t=1.928, df=66, P=0.058). Analysis of variance revealed significant difference between combination genotypes of GSTM1 and GSTT1 for serum testosterone (F=4.167; df=3, 64; P=0.009). The Duncan post hoc test indicated that the combination genotype of "present GSTM1/null GSTT1" had significant higher level of testosterone. There is no evidence that XRCC1 polymorphisms have advantage/disadvantage when population exposed to natural sour gas. The polymorphisms of GSTM1 and GSTT1 modulate serum testosterone concentration in young females exposed to natural sour gas.