Y-chromosome haplogroup architecture confers susceptibility to azoospermia factor c microrearrangements: a retrospective study

Y-chromosome haplogroups and Azoospermia Factor (AZF) analysis in Tunisian infertile male

The aim of the present study was to clarify the implication of Y chromosome genetic variations and haplogroups in Tunisian infertile men. A total of 27 Y-chromosomal binary markers partial microdeletions (gr/gr, b1/b3 and b2/b3) and copy number variation of DAZ and CDY genes in the AZFc region were analysed in 131 Tunisian infertile men with spermatogenic failure and severe reduced sperm concentrations and in 85 normospermic men as controls. Eleven different haplogroups in the overall population study (E3b2; J1J*, E1, E3b*, F, G, K, P/Q, R*, R1* and R1a1) were found. Interestingly, the J1J* haplogroup was significantly more frequent in azoo/oligospermic patients than in normospermic men (35.1% and 22.3%, respectively (p value = 0.04)). Results showed also that patients without DAZ/CDY1 copies loss and without partial microdeletions belonged to the R1 haplogroup. The relative high frequencies of two haplogroups, E3b2 (35.1%) and J (30%) was confirmed in Tunisia. We reported in the present study and for the first time, that J1J* haplogroup may confer a risk factor for infertility in the Tunisian population and we suggested that R1 haplogroup may ensure certain stability to Y-chromosome in Tunisian men.

Association of MSY haplotype background with nonobstructive azoospermia is AZF-dependent: A case-control study

Identifying causal genes of spermatogenic failure on the male-specific region of Y chromosome (MSY) has been a challenging process. Due to the nonrecombining nature of MSY, haplotype-based approaches have recently been shown to be promising in identifying associated MSY haplogroups. We conducted an MSY analysis of nonobstructive azoospermia (NOA) patients in a case-control setting (N = 278 and 105 respectively) to identify modal haplogroups strongly associated with NOA. Patients with AZF deletions (AZF+) and no AZF deletions (AZF-) were compared with the control group. Given the larger sample set of AZF- NOA patients, we further investigated the association based on histopathological severity, namely Sertoli cell-only syndrome and maturation arrest subtypes. We observed no significant enrichment of MSY haplogroups in AZF- azoospermic patients (or its subtypes). However, we observed a strongly significant association between haplogroup J2a* and AZF+ patients (FDR-corrected p = .0056; OR = 7.02, 95%CI 1.89 to 39.20), a haplogroup which also showed significant enrichment for AZFa/b deletions (p = 4x10^-4 ). We conclude that unlike AZF+ patients, AZF- NOA are less likely to have an MSY causative factor with large effect size, thus indicating that the aetiology of AZF- NOA, and to some extent AZFc NOA, is more likely to be based on non-MSY factors.