Shiva Sharestani - Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Seyed Mehdi Kalantar - Abortion Research Centre, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Science, Yazd, Iran. Department of Genetics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Nasrin Ghasemi - Abortion Research Centre, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Science, Yazd, Iran. Department of Genetics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Ehsan Farashahi Yazd - Stem Cell Biology Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

Background: Androgens play a role in the development of male phenotype and spermatogenesis during puberty, the function of which is regulated by the androgen receptor (AR) gene. There is a polymorphism site in exon ۱ of the gene encoding this receptor that can have different frequencies of CAG trinucleotide repeats and leads to the formation of polyglutamine chains of different lengths in the N-terminal domain of the AR protein and reduced sperm production by affecting spermatogenesis. Objective: To investigate whether the cause of a group of unexplained infertilities could be the increased frequency of CAG repeats in the AR gene of patients with oligozoospermia and azoospermia. Materials and Methods: In this case-control study, ۸۴ men including ۴۲ with unexplained infertility As a case group and ۴۲ fertile men as a control group were selected. The frequency of CAG repeats was determined by the polymerase chain reaction method and then the difference in the frequency of these repeats was determined based on the difference in band size on the agarose gel. Results: The mean CAG repeat length in the azoospermia and oligozoospermia group was ۱۷.۵ ± ۰.۶۳ and in the fertile group it was ۱۶.۱۱ ± ۰.۷۵ (p = ۰.۴۶). In addition, most men (۸۸.۱% in the case group and ۷۱.۴۱% in the control group) had ۱۳-۲۳ repeats. Conclusion: No significant correlation was found between CAG repeat length and the risk of male factor infertility in an ethnically defined population of Iranian men. The role of regulatory factors and epigenetic changes should be taken into account too.

Infertility, Azoospermia, Androgens, X chromosome, Spermatogenesis., ناباروری, آزواسپرمی, آندروژن ها, کروموزومX, اسپرماتوژنز.