Mutation screening and CAG repeat length analysis of the androgen receptorgene in Klinefelter's syndrome patients with and without spermatogenesis

Mutations of the androgen receptor (AR) gene give rise to a wide array of p henotypic abnormalities. A systematic analysis of the AR gene in patients w ith 47,XXY has not previously been performed. METHODS: Mutations of the AR gene and expansion of the CAG repeats in exon 1 of the AR gene were studied in 13 patients with Klinefelter's syndrome either with (n = 1) or without (n = 12) spermatogenesis. RESULTS: No abnormalities in the AR gene were det ected by single strand conformational polymorphism analysis. The CAG length s ranged from 17 to 27 (mean +/- SD 22.8 +/- 3.3, median 23) for Klinefelte r patients or from 17 to 28 (mean +/- SD 23.2 +/- 2.6, median 23) for contr ol subjects. X-inactivation analysis for the methylation status of the AR g ene was performed in seven patients who were heterozygous for CAG repeats o f different length, showing that the longer CAG repeat alleles underwent ra ndom but more frequent inactivation in five patients and skewed inactivatio n in two. CONCLUSIONS: An AR gene abnormality does not constitute an import ant factor for impaired spermatogenesis in patients with Klinefelter's synd rome.