Male infertility: Y-chromosome deletion and testicular aetiology in cases of azoo-/oligospermia.

ABSTRACT

The spermatogenesis locus azoospermia factor (AZF) in Yq11 has been delineated into three microdeletion intervals designated as AZFa, AZFb andAZFc. AZFc is the most frequently deleted region. We have studied 270 male infertile patients for various genetic disorders associated with infertile phenotype. In this study, we have presented results of our studies on Y-chromosome deletions, chromosomal abnormalities (Klinefelter syndrome) and histology of testis with the objective of seeing whether there were cases of gonosomic mosaicism and a causal correlation between the genetic disorder; and testicular aetiology could be drawn. In all the 13 cases of Y-chromosome microdeletion, AZFc region and DAZ gene were deleted, while no case of AZFa deletion was detected. This result was at variance with other reports from India, where a considerable fraction of cases showed deletion in AZFa region of the Y-chromosome. Both Y-deleted and non-Y-deleted cases revealed heterogeneous testicular phenotype with comparable severity. This disparity among testicular phenotype in cases with known genetic aetiology and even in cases of unknown aetiology can be attributed to different genetic backgrounds and effect of modifiers. Since male infertility is a multifactorial disorder, the contributions of environmental and occupational insults may not be underestimated.