Association between androgen receptor gene CAG trinucleotide repeat length and testicular histology in older men

ObjectiveTo determine whether the size of CAG repeat in exon 1 of the androgen receptor (AR) gene is related to impaired spermatogenesis in older men.DesignStudy of two groups of older men: one with preserved spermatogenesis and the other with arrested spermatogenesis.SettingUniversity teaching hospital.Patient(s)Twenty-eight men aged from 53 to 102 years.Intervention(s)The DNA fragment encoding the AR polyglutamine tract was amplified from DNA of testis tissue.Main Outcome Measure(s)The size of the CAG repeat was evaluated by using fluorescent-labeled polymerase chain reaction performed on an ABI Prism 377 DNA sequencer followed by automated analysis with Genscan 3.1.2 software.Result(s)Mean CAG repeat length was 22.76 ± 3 in the group of 13 aged men with preserved spermatogenesis and 21.86 ± 2.23 in the group of 15 aged men with arrested spermatogenesis.Conclusion(s)Impaired spermatogenesis in elderly men does not seem to be correlated with the AR gene CAG repeat length, which therefore does not appear to be a risk factor for impaired spermatogenesis in older men.