Association of DAZ1/DAZ2 deletion with spermatogenic impairment and male infertility in the South Chinese population.

PURPOSE

To investigate the effect of the deleted in azoospermia (DAZ) copy cluster deletion on spermatogenesis in the South Chinese population.

METHODS

In this study, the prevalence and characteristics of different DAZ copy cluster deletions and their association with spermatogenic failure were analyzed. A total of 186 infertile men with different spermatogenic impairments and 190 normozoospermic fertile men were studied. Three DAZ-specific single nucleotide variant loci and seven AZFc-specific sequence-tagged sites were examined using polymerase chain reaction (PCR)-restriction fragment length polymorphism and routine PCR.

RESULTS

Gr/gr deletions were observed in a total of 9 of the 190 normozoospermic fertile men, and 11 gr/gr deletions were found in 186 infertile men. In addition, 3 b2/b3 deletions were identified in the infertile, but not in the fertile men. DAZ-SNV loci analysis revealed 4 DAZ copies that had 8 gr/gr-DAZ3/DAZ4 deletions and 1 gr/gr-DAZ1/DAZ2 deletion in the fertile men (8/190 vs. 1/190, p = 0.037). Analysis of DAZ deletion copies in infertile men revealed 10 gr/gr-DAZ1/DAZ2 deletions, 1 gr/gr-DAZ3/DAZ4 deletion (10/186 vs. 1/186, p = 0.011) and 3 b2/b3-DAZ1/DAZ2 deletions (13/186 vs. 1/186, p = 0.002).

CONCLUSIONS

Analysis of DAZ gene copies in AZFc microdeletions suggests that the contribution of the different deletions to male infertility varies. Removing DAZ1/DAZ2 seems to be associated with spermatogenic impairment, whereas removing DAZ3/DAZ4 seems to have little or no effect on fertility in the South Chinese population.