The (TAAAA)n microsatellite polymorphism in the SHBG gene influences serum SHBG levels in women with polycystic ovary syndrome

Hyperandrogenaemia is a common feature of polycystic ovary syndrome (PCOS). The sex hormone-binding globulin (SHBG) gene was proposed as being a PCOS candidate gene. A possible influence of the microsatellite polymorphism (TAAAA)(n) in the SHBG gene on serum SHBG levels in PCOS patients was investigated. METHODS: One hundred and twenty-three PCOS patients and 110 age-matched controls were included in the study. Peripheral blood samples were obtained. Genotyping of the (TAAAA)(n) polymorphism in the SHBG gene was performed. Serum LH, FSH, SHBG and total testosterone concentrations were determined. RESULTS: SHBG alleles with 6-11 TAAAA repeats were found. None of the SHBG alleles or genotypes were present at a significantly more frequent rate in PCOS patients compared with controls. Serum SHBG levels were significantly lower (P < 0.001) in PCOS patients compared with controls and were found to be strongly influenced by the (TAAAA)(n) SHBG polymorphism, in both the PCOS (55.3 %) and control (33.1 %) groups of patients. CONCLUSIONS: The (TAAAA)(n) SHBG gene polymorphism might be an important predictor for serum SHBG levels and, consequently, for hyperandrogenaemic clinical presentation of PCOS.