The association of cytosine-adenine-guanine repeat polymorphism in the androgen receptor gene with nodulocystic acne in Egyptian patients


  • Nehal M. Zuelfakkar Department of Dermatology, Venereology and Andrology, Ain Shams University, Cairo, Egypt
  • Nader F. Ragab Department of Dermatology, Venereology and Andrology, Ain Shams University, Cairo, Egypt
  • Abeer Shehab Department of Clinical Pathology, Ain Shams University, Cairo, Egypt
  • Momena Nagy Faculty of Medicine, Ain Shams University, Cairo, Egypt



Androgen receptors, CAG repeat, Nodulocystic acne


Background: The role of androgens in acne pathophysiology has been supported by long-standing clinical and experimental observations.

Methods: Genotyping for the androgen receptor gene was performed by PCR-based fragment length analysis, aiming to investigate cytosine-adenine-guanine (CAG) repeat polymorphism in Egyptian nodulocystic acne patients to clarify its relevance to the pathogenesis. Detailed frequency of CAG repeats number in patients and control groups, in 25 males and 25 females and Comparison of CAG repeat number regarding demographic and clinical characteristics was performed.

Results: It was found that females had a higher frequency of longer CAG repeats compared to males, while in control group there was an even distribution of CAG number repeats in both females and males. Male and female acne patients had significantly lower number of CAG repeats compared to controls with statistically significant difference (p≤0.05). Comparison of CAG repeat number regarding demographic and clinical characteristics revealed no significant correlation or association with patients’ age, duration of acne, onset or course of the disease.

Conclusions: These findings support the hypothesis that CAG repeats number affects AR activity, therefore, acne development and severity. Moreover, analysis of CAG repeats number in acne patients can be of considerable importance in the treatment strategy, indicating the role of antiandrogen therapy in acne patients.


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