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

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