Cytogenic and molecular studies of male infertility in cases of Y chromosome balanced reciprocal translocation.

Y-autosomal translocation has been previously reported in association with male infertility; however, the mechanisms of Y-autosomal translocation and nonobstructive azoospermia or severe oligospermia remain unclear. G-banding and fluorescence in situ hybridization (FISH) were performed to analyze the translocation of chromosomes, and a single nucleotide polymorphism (SNP) genotyping assay was used to test mutations. The present study describes three new cases with a de novo balanced translocation t(Y; 13), t(Y; 9) and t(Y; 6). To further explore the genotype-phenotype correlation, G-banding and FISH were performed and indicated the presence of a derivative chromosome. The SNP genotyping assay using a microarray revealed no abnormality, especially in the Y chromosome. Molecular deletion analysis demonstrated that no microdeletion was detected in the azoospermia factor region of the Y chromosome in the examined, infertile men. Based on these observations, the authors proposed the hypothesis that a position effect involving unknown spermatogenesis regulatory gene(s) serves a key role in male infertility.