Insight into Genetic × Epidemiological factors in male infertility: synergistic effect of AZFc partial deletions and habits of smokeless-chewing tobacco

Abstract The Y chromosome AZF partial deletions exhibit variations in its association with male infertility across the population divides, and intriguing. Here we have analysed distinct partial deletions (gr/gr, b1/b3 and b2/b3) of the AZFc region among the 728 Bengali-speaking men and compared them with 264 age-matched proven-fertile control subjects. The gr/gr deletion was found to be frequent among azoospermic (P = 0.001) and oligozoospermic (P = 0.03) subjects, and b1/b3 deletions were detected to be significant among severe-oligozoospermic men (P = 0.0405). Furthermore, we analysed the interactions of these deletions with the habits of smokeless chewing tobacco among the participating subjects, taking opportunity of large epidemiological data of the participating subjects. The logistic regression model revealed that the infertile subjects bearing any type of microdeletion and also SCT users had an elevated risk of infertility (P = 0.002). Our work helps to get more insight into the cause of male infertility in the light of gene-environment interaction (G × E) and brings us a significant step closer towards understanding the aetiology of spermatogenesis failure in men.