Male Infertility: Genetics of Spermatogenic Failure

Spermatogenesis is a complex biological process that requires the coordination of thousands of genes. Perhaps because of the large number of genes involved, spermatogenic failure occurs frequently and affects approximately 1% of men. While environmental and genetic factors likely contribute to this disorder, it is thought that the majority of cases have an underlying genetic basis. The two most common genetic causes are deletions on the Y chromosome and cytogenetic abnormalities (/e.g./ Klinefelter syndrome, XXY), which each account for roughly 10-15% of cases of complete spermatogenic failure. Point mutations in several other genes have also been linked to spermatogenic failure, but their collective prevalence is very low. Thus, for approximately 70% of men with spermatogenic failure, the genetic cause remains unknown. We hypothesize that a disproportionate number of these remaining genetic variants reside on the sex chromosomes because they are hemizygous... (for more see dbGaP study page.)