The CAG repeat length was investigated in 307 Iranian men, 104 infertile men with NOA and 203 fertile controls using primers flanking the CAG repeat region in exon 1 of the AR gene.
The most common allele in the patients and controls was 23 (18.39%) and 21 (19.70%) CAG repeats with the mean number of 21.97 ± 2.772 and 21.10 ± 2.674, respectively (P = 0.013).
Although our results indicate a significant negative correlation between the length of CAG repeat and male infertility, however, other genetic modifiers may be required in order to cause male infertility.