Combination of short CAG and GGN repeats in the androgen receptor gene is associated with acne risk in North East China

Background: Acne vulgaris is one of the most common skin disorders, and androgen is known to play a key role in the development of acne. However, the exact genetic mechanism by which androgen receptor (AR) gene affects acne development is still unclear. Objective: Our study aimed to investigate whether CAG and GGN polymorphism of the AR gene are associated with acne risk. Patients and methods: Two hundred thirty-eight patients and 207 controls were included in the study. The repeat lengths of the AR gene were determined by GeneScan analysis. Results: Men with CAG < 23 and women with CAG < 24 had significant risk compared to those men with CAG ≥ 23 [odds ratio (OR), 2.07; 95% confidence interval (95% CI), 1.21-3.54] and women with CAG ≥ 24 (OR, 2.05; 95% CI, 1.18-3.56). In males, GGN repeats, considered independently of the CAG repeat, have no significant effect on the acne risk; however, when combined with CAG repeats, the acne patients exhibited significantly higher frequency of the haplotypes CAG < 23/GGN ≤ 23 (OR, 3.33; 95% CI, 1.10-10.07; P < 0.05) compared with the controls. Conclusion: Our results of this study strongly indicated that a shorter CAG repeat length and specific haplotypes of AR attributed to the risk of acne development and thus could serve as a susceptibility marker.