Natural transmission of a partial AZFb deletion of the Y chromosome over three generations: case report.

The natural transmission of microdeletions of the Y chromosome is occasionally reported in the literature. Here we describe the natural transmission of a partial AZFb deletion over three generations. PCR amplification of several sequence tagged site markers in the three AZF regions of the Y chromosome was carried out in a patient with oligoasthenoteratozoospermia, his father and his naturally conceived son. The deletion was confirmed by Southern blotting. The propositum, his father and his son showed a probably identical, partial deletion of the distal part of the AZFb region, involving sY130 and sY143. The deletion was confirmed by Southern blotting using the sY130 probe. Partial AZFb microdeletions can be associated with moderate oligozoospermia allowing natural conception and therefore natural transmission of this genetic anomaly. Further studies are needed to define the pathogenetic significance of microdeletions involving sY130 and sY143.