No association found between gr/gr deletions and infertility in Brazilian males

The Y chromosome carries several spermatogenesis genes distributed in three regions: AZFa, AZFb and AZFc. Microdeletions in these regions have been seen in 10 % of sterile males with azoospermia or oligozoospermia, the most frequent of them being char-acterized by a complete deletion of AZFc region. A partial AZFc deletion named gr/gr has been singled out as a risk factor for spermatogenic failure. However, other authors have diagnosed it as a polymorphic deletion with no clinical relevance. We decided to investigate the association of gr/gr deletion and infertility in Brazilian males. We analysed 350 individuals (110 azoospermic, 122 fertile and 118 presumably fertile) and observed 12 g/gr deletions: five in infertile men (4.5%), three among fertile males (2.5%) and four in probably fertile individuals (3.4%). These differences were not statistically significant. Then, we decided to ascertain whether the clinical impact of the gr/gr deletion was associated with the type of Y chromosome. We have identified Y-chromosome haplogroups using 22 unique event polymorphisms (UEPs). Among the individuals with the gr/gr deletion, we found haplogroups R, K*, F*, E1, E3b2 and E3b*, all of which are common in white Brazilian males, and none revealed a particular association with infertility. Taken together, these results show no evidence of association between the occurrence of gr/gr deletion and male infertility. Key words: AZFc/gr-gr deletion/male infertility/minisequencing/Y chromosom