Androgen receptor gene CAG repeat polymorphism in women with polycystic ovary syndrome

Objective: To evaluate the role of the androgen receptor (AR) gene CAG repeat in women with polycystic ovary syndrome (PCOS). Design: Case control study. Setting: University department of obstetrics and gynecology. Patient(s): Women with (n = 114) or without (n = 205) PCOS. Intervention(s): Peripheral blood sampling was done for DNA analysis and serum hormone measurements. Main Outcome Measure(s): CAG repeat length and serum androgen levels. Result(s): No statistically significant CAG repeat length differences were found between patients and controls. We conducted a detailed analysis after dividing PCOS patients according to their free testosterone levels. The high free testosterone group had a statistically significantly longer mean biallelic average (24.0 ± 2.0 vs. 23.0 ± 1.5), short (22.5 ± 1.8 vs. 21.7 ± 1.9), and long (25.5 ± 2.9 vs. 24.4 ± 1.9) allelic lengths than the normal free testosterone group. In PCOS patients, a statistically significant correlation was found between biallelic average length and free testosterone concentration, either unadjusted or after adjustment. Conclusion(s): The AR gene CAG repeat polymorphism may contribute to the serum concentration of free testosterone in PCOS patients. A subset of PCOS patients with relatively longer CAG repeats (less AR activity) tended to show a higher serum androgen concentration.