Infertile males with testicular failure, particularly those with hypospermatogenesis, are more likely to have a longer androgen receptor polyglutamine tract than controls.
During recent years several studies have suggested that a slight increase in the number of CAG repeat sequences in exon 1 of the androgen receptor gene causes idiopathic oligozoospermia.
Remarkably, several AR mutations associated with oligospermia and androgen insensitivity syndrome map to Pro-390, the conserved proline downstream of the first SC motif in AR.
We found that azoospermic patients had higher mutation rates on exons 1 and 4 of the androgen receptor gene, when compared to other alterations that also lead to infertility, such as oligozoospermia and teratozoospermia.