A novel Y chromosome microdeletion potentially associated with defective spermatogenesis identified by custom array comparative genome hybridization

Male infertility is a major health problem worldwide. Oligospermia and azoospermia are the most common symptoms of this disorder. Despite recent advances, the aetiopathogenesis of defective spermatogenesis remains largely uncertain. The aim of this study is to discover unknown or novel chromosome aberrations associated with male reproductive failure. We developed a high-resolution custom array comparative genomic hybridization for initial screening of copy number variations in 10 patients with idiopathic oligozoospermia and azoospermia and eight normal fertile men. We found that deletions were mainly located in the deleted-in-azoospermia subregion and were confined to patients. More importantly, an interesting microdeletion of the Y chromosome designated as D01 was detected in four out of 10 patients with oligozoospermia and azoospermia. We validated this recurrent deletion in nine out of 100 additional infertile men using polymerase chain reaction assays, whereas, it was not present in 100 proven fertile controls(P = 0.002). Furthermore, a bioinformatics analysis demonstrated that the 5' terminal of D01 is situated proximal to several conserved transcription factor binding sites within the Y chromosome. Our study indicated that this newly identified Y chromosome deletion might be potentially associated with impaired spermatogenesis and it is worthy of further investigations in larger cohorts.