Y-haplotypes and idiopathic male infertility in an Indian population

Kiran Singh,Rajiva Raman

doi:10.4103/0971-6866.50865

Abstract

Infertility being a multifactorial disorder, both genetic and environmental factors contribute to the etiology of infertile phenotype. Chromosomal anomalies and Y-microdeletion are the established genetic risk factors of male infertility. Y-haplotypes has been found as risk factor for male infertility in certain populations, though in certain others no association has been reported, suggesting a population-specific association of these variations with male infertility. In a case-control study, 165 azoo-/oligospermic patients and 200 controls were haplotyped for certain Y-haplogroups for a possible association with idiopathic male infertility in an Indian population. Analysed Y-haplogroups showed no association with infertile phenotype. Thus this genetic factor is not a risk for infertility in the studied Indian population but that does not rule out the possibility of any of them, to be a risk in other populations.

Highlights

The human Y chromosome contains over 60 million nucleotides, and act as a genetic determinant of the male characteristic features
A few studies have shown an association of certain Y-haplogroups with low sperm count and azoospermia in certain populations which fortifies the idea that selection processes are still active on the Y-chromosome.[1,6]
Et al.: Y-haplotype and male infertility idiopathic azoospermic/oligospermic (157 azoospermic and 8 severe oligospermic with sperm count less than 1 million,mL) and 200 fertile control individuals of comparable age group (30, SD +3), belonging to same geographical region were haplotyped for the binary alleles on the Y-chromosome

Summary

Introduction

The human Y chromosome contains over 60 million nucleotides, and act as a genetic determinant of the male characteristic features. Though rearrangement or sequence variation in these genes is expected to lead to impaired spermatogenesis and reduced sperm count,[1,2] seldom has a mutation in a single gene been associated with nonobstructive male infertility. The genetic cause of idiopathic azoospermia and oligospermia is predominantly associated with chromosomal aneuploidy, rearrangements, and microdeletions in the AZF region of the Y-chromosome.[3,4] The lack of inter-chromosomal recombination in larger part of the Y-chromosome facilitates accumulation of a variety of slow mutating binary markers such as SNPs. On the other hand, the genetic cause of idiopathic azoospermia and oligospermia is predominantly associated with chromosomal aneuploidy, rearrangements, and microdeletions in the AZF region of the Y-chromosome.[3,4] The lack of inter-chromosomal recombination in larger part of the Y-chromosome facilitates accumulation of a variety of slow mutating binary markers such as SNPs Variation in their relative frequency in different populations gives rise to diverse chromosomal haplotypes.[5] A few studies have shown an association of certain Y-haplogroups with low sperm count and azoospermia in certain populations which fortifies the idea that selection processes are still active on the Y-chromosome.[1,6]

Methods

Results

Conclusion