Y chromosome microdeletion in a father and his four infertile sons.

Microdeletions of Yq are associated with azoospermia and severe oligozoospermia. In general, men with deletions are infertile and therefore deletions are not transmitted to sons unless in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are performed. We report an unusual family characterized by multiple members with infertility and Yq microdeletion. Complete reproductive history, semen analyses and blood samples were elicited from relevant family members. DNA preparation and quantification were performed using commercial kits. A total of 27 pairs of sequence tagged sites based primer sets specific for the Y microdeletion region loci were used for screening. Southern blots using deleted in azoospermia (DAZ) and ribosomal binding motif (RBM) cDNAs were then analysed for confirmation. The proband, his three brothers and father were all found to be deleted for DAZ but not RBM. At the time of analysis, the proband's father was azoospermic whereas his four sons were either severely oligozoospermic or azoospermic. Unlike their father, the four sons are infertile and have no offspring, except for one of them who achieved a daughter only after IVF/ICSI treatment for infertility. Microdeletions of Yq involving the DAZ gene are associated with a variable phenotypic expression that can include evidently normal fertility.