Y-chromosome microdeletions and male infertility.

A genetic basis of infertility may exist in many men currently classified as having idiopathic infertility. Approximately 7% of infertile men harbour submicroscopic deletions of the Y chromosome that are not detectable on routine karyotype. Two candidate gene families, namely the RNA-binding motif-containing gene family, and the deleted-in-azoospermia gene family, have been cloned by deletion mapping of infertile men with Y microdeletions and proposed as candidates for the putative azoospermia factor. The precise function of these two gene families remains unclear. It is likely that additional Y-specific and autosomal genes will be implicated in other subsets of male infertility. Recognition of the association of Y deletions and other genetic defects with male infertility has implications for the diagnosis, treatment, and genetic counselling of infertile men, particularly those who are being considered for intracytoplasmic sperm injection.