Y chromosome microdeletion screening in infertile men

Molecular analysis of Y-chromosomal microdeletions is routinely performed i n the work-up of male infertility, in order to establish a diagnosis and fo r genetic counseling of the couple, since such microdeletions are transmitt ed to the male offspring. The review of published data shows that microdele tions are relatively common in patients with azoospermia or severe oligozoo spermia, with wide variations in the reported deletion frequency depending mainly on the selection criteria. In general, patients with proximal deleti ons, involving the AZFa and/or the AZFb region show severe defects of sperm atogenesis with a high prevalence of Sertoli cell only syndrome, while dele tions of the distal AZFb and of the AZFc region can be compatible with resi dual spermatogenesis. Microdeletions have been only sporadically found in n ormozoospermic patients. For the time being the molecular analysis of micro deletions of the Y chromosome is indicated in infertile patients with sperm concentration <5x10(6)/ml and in men undergoing assisted reproduction tech niques, since the genetic defect and, most probably, the related infertilit y problem will be transmitted to the sons.