SHBG (sex hormone-binding globulin) is a transport protein specific for dihydrotestosterone, testosterone and estradiol. The missense mutation in exon 8 (GAC→AAC) causing the amino acid exchange D327N correlates accordingly to literature data with higher SHBG levels.
We studied the possible association of this polymorphism with polycystic ovary syndrome (PCOS) and its influence on anthropometric and biochemical parameters in 247 PCOS patients in comparison to 109 healthy control women.
The D327N polymorphism (wild-type a variant allele) was detected using PCR-RFLP method (restriction enzyme Bbs-I). Statistical evaluation: Chi2 test, ANOVA (Statgraphics Plus v.5.1, USA). There was no significant difference in genotype distribution between PCOS and controls (Chi2=0.30, P=0.58).
Biochemical parameters were evaluated in women without any medication i.e. in 73 control women and in 247 PCOS. We did not find any association of the variant allele with plasma SHBG level. SHBG was associated only with body mass index (P<0.0004). The variant allele carriers had significantly lower levels of testosterone (P<0.05) and 17-hydroxyprogesterone (P<0.05), but the significance was achieved only in the age group above 30 years.
Conclusion: The influence of adiposity on SHBG level was probably stronger than the contribution of D327N polymorphism. However, this polymorphism could influence the androgen levels.
Study was approved by local Ethical Committee, supported by grant GA CR 301/04/1085 and IGA MH CR NR/7809-5.