Objective: To determine whether expansion of CAG repeats in exon 1 of the androgen receptor is correlated with impaired spermatogenesis in patients with male idiopathic infertility.
Design: A retrospective study.
Setting: Medical school in Besançon, France.
Participant(s): Thirty-seven infertile patients with azoospermia or oligospermia and 50 fertile controls.
Intervention(s): History, physical, hormonal assays, semen analysis, and collection of blood samples in order to study the androgen receptor's gene.
Main outcome measure(s): Blood samples were collected from each infertile patient and control. The length of the CAG repeat segment was evaluated by using polymerase chain reaction (PCR) electrophoresis in exon 1 and PCR single-strand conformation polymorphism in exons 2-8.
Result(s): The mean length of the CAG repeats was significantly different between infertile and fertile patients (23.91 +/- 0.5 vs. 22.20 +/- 0.4). No mutation was detected in exons 2-8 of the androgen receptor gene in infertile patients.
Conclusion(s): Expansion of the CAG repeat segment of the androgen receptor is correlated with male idiopathic infertility. The number of CAG repeats may therefore have a modulatory effect on normal androgen receptor function.