Objective: Sex hormone binding globulin (SHBG) levels are often low in women with polycystic ovary syndrome (PCOS). In addition to metabolic and nutritional factors, SHBG levels are determined by genetic polymorphisms in SHBG gene. The aim of this study was to investigate the association of polymorphisms in exon 8 of SHBG gene with anthropometric and biochemical features of women with PCOS.
Design: Prospective, observational study.
Patients: One hundred and ninety-four women with PCOS.
Main outcome measure(s): Genotype analysis of exon 8 in SHBG gene was performed. Serum SHBG, total testosterone, free testosterone, 17-α-hydroxyprogesterone, TSH, PRL, glucose and insulin levels were determined. MAIN FINDING(S): Single nucleotide polymorphism (SNP) E326K located at codon 326 in exon 8 of SHBG gene was identified. Serum SHBG levels decreased significantly with increasing copy number of the variant allele for SNP E326K after adjustment for BMI, androgenic and insulin-related traits. Genotype analysis also revealed SNP, rs6259, located at codon 327 in exon 8 of SHBG gene, which is not associated with SHBG levels.
Conclusion: SNP, E326K, in exon 8 of SHBG gene may influence the metabolism of SHBG independently of BMI, androgenic and insulin-related features in women with PCOS.