Androgen receptor cytosine, adenine, and guanine trinucleotide repeat polymorphism in Korean patients with endometriosis: A case-control study.

Study Objective: To investigate the association between the androgen receptor (AR) cytosine, adenine, and guanine (CAG) repeat polymorphisms and endometriosis.

Study Design: A prospective case-control, genetic association study was performed on women with surgically proven endometriosis (n=421) and controls free of endometriosis (n=349). AR CAG repeat lengths were determined from peripheral blood samples. The difference in the frequency of each alleles were compared in patients with endometriosis and controls using Chi-square test.

Main Results: No significant difference in biallelic length mean between patients and controls was observed. Alleles containing 24 CAG repeats were significantly more frequent in stage I-II (mild) endometriosis than in the control samples (19.8% and 13.3%, respectively; OR 1.60, 95% CI 1.04-2.47). Additionally, a higher frequency of both alleles with 24 or more CAG repeats was observed in individuals with mild endometriosis, in comparison with the controls (25.6% and 15.2%, respectively; OR 1.92, 95% CI 1.09-3.38).

Conclusions: AR gene CAG repeat polymorphisms are associated with the increased risk of mild endometriosis.