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.