CAG polymorphism in the androgen receptor gene in women may be associated with nodulocystic acne

Introduction
Acne vulgaris (AV) is a multifactorial, inflammatory disease of the pilosebaceous unit. Hormones play a major role in the pathogenesis of acne. In cases of hyperandrogenism; hirsutism, acne, seborrhoea and alopecia appear in women. However, severe acne can also be seen without evidence of hyperandrogenism. In this case, hypersensitivity of the androgen receptor gene (ARG) encoded in the X chromosome, which is the only receptor for androgens, can be considered. ARG contains a polymorphic CAG triple loop encoding the polyglutamine pathway at the 5’end of exon 1.

Aim
To investigate CAG repeat polymorphism in the ARG in nodulocystic acne patients in Turkish population.

Material and methods
This prospective clinical study was conducted between 2016 and 2017 in accordance with the tenets of the Declaration of Helsinki. DNA isolation from blood was performed using the RTA® Genomic DNA Isolation Kit. The fragment lengths obtained from the device to determine CAG repeat numbers were analysed based on –288 bp length 22 CAG repeat content.

Results
A total of 199 subjects; 100 patients (51 males, 49 females) and 99 controls (49 males, 50 females) were included in the study. The mean allele length in the patient group was 19.34; and 19.7 in the control group. There was a statistically significant difference between female patients and the control group, when the patients and control groups were compared by gender (p = 0.0059).

Conclusions
The CAG trinucleotide repeat count in the ARG may be associated with acne, without hirsutism findings.