Reduction in the DAZ gene copy number in two infertile men with impaired spermatogenesis

Microdeletions of Yq are associated with azoospermia and severe oligozoospe rmia. Recently, we described a new molecular genetic strategy based on the denaturing gradient gel electrophoresis (DGGE) to rapidly identify deletion s of the Y chromosome that include the DAZ locus. Using this approach, we h ave shown not a complete deletion but only a reduction in the number of cop ies of the DAZ gene by PCR-DGGE in two oligozoospermic patients. These resu lts have been confirmed by Southern blot analysis. This finding suggests th at partial deletion of the DAZ cluster could be cause of impaired spermatog enesis. (C) 2001 editions scientifiques et medicales Elsevier SAS.