A to G transitions at 260, 386 and 437 in DAZL gene are not associated with spermatogenic failure in Indian population

Abstract

The autosomal DAZL (Deleted-in-Azoospermic-Like) gene, mapped to the short arm of the human chromosome 3, is the precursor for the Y-chromosomal DAZ cluster, which encodes for putative RNA-binding proteins. Mutations in the DAZL have been reported to be associated with spermatogenic failure in Taiwanese population but not in Caucasians. As there was no study on Indian populations, we have analysed the entire coding sequences of exons 2 and 3 of DAZL in a total of 1010 men from Indian subcontinent, including 660 infertile men with 598 non-obstructive azoospermia, 62 severe oligozoospermia and 350 normozoospermic fertile control men, to investigate whether mutation(s) in the DAZL is associated with male infertility. Interestingly, none of our samples (1010) showed A386G (T54A) mutation, which was found to be associated with spermatogenic failure in Taiwanese population. In contrast, A260G (T12A) mutation was observed in both infertile and normozoospermic fertile control men, without any significant association with infertile groups (χ²=0.342; p=0.556). Similarly, we have found a novel A437G (I71V) mutation, which is also present in both infertile and normozoospermic fertile control men without any significant difference (χ²=0.476; p=0.490). Our study clearly demonstrates the complete absence of the A386G (T54A) mutation in Indian subcontinent and the other two mutations- A260G (T12A) and A437G (I71V)- observed are polymorpic. Therefore, we conclude that these mutations in the DAZL gene are not associated with male infertility in Indian subcontinent.