Shorter CAG repeats in the androgen receptor gene may enhance hyperandrogenicity in polycystic ovary syndrome

Abstract

Background. The main goal of the present study was to assess the influence of the androgen receptor gene CAG repeat polymorphism on hyperandrogenism and its phenotypical features in patients with polycystic ovary syndrome (PCOS).

Methods. CAG repeat lengths were analyzed in 97 oligo-anovulatory women with ultrasound features of PCOS. All individuals were assessed for endocrine parameters and their phenotypical features were recorded. These parameters were correlated with the CAG repeat lengths.

Results. PCOS patients with a bi-allelic mean lower than 21 repeats had lower dihydrotestosterone levels (p = 0.007), lower androstenedione levels (p = 0.023), lower luteinizing hormone levels (p = 0.023), a lower luteinizing hormone/follicle-stimulating hormone ratio (p = 0.021) and the highest percentage of patients with acne and/or hirsutism (p = 0.021).

Conclusions. Our findings support the hypothesis that the PCOS phenotype may result from either elevated androgen levels or an enhanced sensitivity to androgens caused by a more active androgen receptor.

Keywords:

• Polycystic ovary syndrome
• CAG repeat
• androgen receptor
• hirsutism
• acne
• testosterone
• dihydrotestosterone
• androstenedione