Y chromosome haplogroups may confer susceptibility to partial AZFc deletions and deletion effect on spermatogenesis impairment.

BACKGROUND Partial AZFc deletions related to testis-specific gene families are common mutations of the Y chromosome, but their contribution to spermatogenic impairment is still unresolved, and the risk factors for the formation of the deletions remain unknown. With this in mind, we investigated the possible association between Y chromosome haplogroups and predisposition to partial AZFc deletions and their effect on spermatogenesis in a Chinese population. METHODS The haplogrouping was carried out using 12 polymorphic loci on the Y chromosome in 269 non-AZFc-deleted controls with an unknown spermatogenic status and 214 men with a partial AZFc deletion defined by the absence of the sequence-tagged site and sequence family variant loss of the DAZ and CDY1 genes. In the latter group, 57 men had normozoospermia and 157 men had azoo/oligozoospermia. Among these, 122 had a de novo partial AZFc deletion. RESULTS Y haplogroup distribution differed significantly between men with a de novo partial AZFc deletion and the control group, and between men with a specific subtype of the partial AZFc deletions and the control group. Further, partial AZFc deletions gave rise to spermatogenesis impairment in some Y haplogroups. CONCLUSIONS The findings indicate that some monophyletic Y chromosomes may be associated with predisposition to specific subtypes of partial AZFc deletion and adverse effect on spermatogenesis. Although these deletions were not confirmed with gene dosage analysis, the results suggest that Y chromosome background is an important factor that affects partial AZFc deletion formation and its contribution to spermatogenic failure.