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

Abstract

Objective: To determine whether the size of CAG repeat in exon 1 of the androgen receptor (AR) gene is related to impaired spermatogenesis in older men.

Design: Study of two groups of older men: one with preserved spermatogenesis and the other with arrested spermatogenesis.

Setting: University 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.