Y-chromosome haplogroups and susceptibility to azoospermia factor c microdeletion in an Italian population

Abstract

Background: A limited number of studies aimed at investigating the possible association of Y-chromosome haplogroups with microdeletions of the azoospermia factors (AZFs) or with particular infertile phenotypes, but definitive conclusions have not been attained. The main confounding elements in these association studies are the small sample sizes and the lack of homogeneity in the geographical origin of studied populations, affecting, respectively, the statistical power and the haplogroup distribution. Materials and methods: To assess whether some Y-chromosome haplogroups are predisposing to, or protecting against, azoospermia factor c (AZFc; b2/b4) deletions, 31 north Italian patients carrying the AZFc b2/b4 microdeletion were characterised for 8 Y-chromosome haplogroups, and compared with the haplogroup frequency shown by a north Italian population without the microdeletion (n = 93). Results and discussion: A significant difference was observed between the two populations, patients with microdeletions showing a higher frequency of the E haplogroup (29.3% vs 9.7%, p,0.01). The geographical homogeneity of the microdeleted samples and of the control population, controlled at microgeographical level, allows the possibility that the geographical structure of the Y genetic variability has affected our results to be excluded. Conclusion: Thus, it is concluded that in the north Italian population Y-chromosome background affects the occurrence of AZFc b2/b4 deletions.

Y chromosome microdeletions in infertile men: prevalence, phenotypes and screening markers for the Indian population

“…An influence of Y chromosome background (e.g. haplogroups) has been suggested as a possible cause in propensity of the Yq deletions [4]. Whether Y chromosome haplogroups contribute to the lower microdeletion frequency observed in the Indian infertile men needs to be investigated.…”

Greater prevalence of Y chromosome Q1a3a haplogroup in Y-microdeleted Chilean men: a case–control study

“…In addition to Y chromosome microdeletions and other less frequent mutations [6,12,14], several studies have proposed that there may be other factors, possibly associated with the environment and/or specific genetic background, that may affect the susceptibility to suffer spermatogenic defects [1,14,32,33,39,44,45].…”

“…Regarding the Y chromosome, several studies have suggested that some lineages or haplogroups of the Y chromosome may confer susceptibility to complete-or partial-AZFc deletions [1,44,45]. There are various known binary markers whose low rate of mutation represent unique events in the evolutionary process, allowing to build hierarchical phylogenetic haplogroups of the Y chromosome [10,23].…”

“…Even though the genetic susceptibility to spermatogenic failure can be influenced by the AZFc-partial deletions, it also has been related to other structural changes not related to these AZFc deletions [45]. In fact another study from Northern Italy observed a higher prevalence of the E haplogroup among patients with complete AZFc deletions ("b2/b4") [1].…”

DAZ duplications confer the predisposition of Y chromosome haplogroup K* to non-obstructive azoospermia in Han Chinese populations

“…In addition, many Y-linked variations can be genetic markers to study the roles of Y chromosomal factors in spermatogenic impairment (Yang et al, 2008). The past several years have witnessed an explosion in identification of the Y chromosome haplogroups (Y-hgs) associated with increased risk of spermatogenic impairment (Kuroki et al, 1999;Previdere et al, 1999;Krausz et al, 2001;Carvalho et al, 2003;Arredi et al, 2007). In our previous study with a limited sample size, we suggested the susceptibility of a group of Y chromosomes to spermatogenic impairment in Han Chinese .…”