Clinical, cytogenomic, and molecular characterization of isodicentric Y-chromosome and prediction of testicular sperm retrieval outcomes in azoospermic and severe oligozoospermic infertile men.

Abstract

Sex chromosome abnormalities are associated with male infertility. The aim of this study was to characterize the clinical, cytogenetic, and molecular findings of 12 infertile men with isodicentric Y-chromosome [idic(Y)] abnormalities diagnosed over a period of 13years. Chromosomal analyses of peripheral blood samples were done using standard procedures. Fluorescence in situ hybridization (FISH) analysis was performed on metaphase spreads of the patients. Multiplex polymerase chain reaction (PCR) using several sequence-tagged site (STS) primer sets within the long arm of Y-chromosome was used to detect AZF deletions.The breakpoints and copy number variations (CNV) were identified by array comparative genomic hybridization analysis (aCGH) analysis.The short-stature homeobox (SHOX) gene deletions were verified using multiplex ligation-dependent probe amplification (MLPA) analysis. Twelve infertile men were diagnosed cytogenetically with idic(Y). The karyotypes of two of the patients were non-mosaic, and the remaining karyotypes showed various degrees of mosaicism. SHOX gene deletion was found in two of the four patients with short stature, and the remaining two patients had shown a 45,X dominant cell line (33.3%). The most common breakpoints for idic(Yq) and idic(Yp) were found to be in Yq11.222 and Yp11.32, respectively. Semen analysis of ten patients (83.3%) demonstrated azoospermia, and the remaining two patients (16.7%) showed severe oligoasthenoteratozoospermia (OAT). In total, 33% (4/12) of idic(Y) patients with or without microsurgical testicular sperm extraction (microTESE) had sperm retrieval. Twelve patients with idic(Y) and different breakpoints of Y-chromosome were characterized using multiple detection strategies. Sperm retrieval outcomes of patients either with idic(Yp) or idic(Yq) showed the possibility to find sperm by microTESE.