Y chromosome microdeletion analysis reveals predominant azfc deletions and absence of germline specific deletions among idiopathic infertile males in a south Indian population

Y chromosome microdeletions in any of the three azoospermia factor loci AZFa, AZFb and AZFc affects spermatogenesis causing irreversible male infertility. In the present study Yq deletion frequency, deletion types and associated infertile conditions were analyzed among240 idiopathic infertile males (102 severe oligospermic and 138 azoospermic) and 100 fertile control individuals ofa south Indian population previously not assessed.Polymerase chain reaction analysis for Yq microdeletions was performed using genomic DNA employing eight sequencetagged sites markers. Germ line specific Yq deletions werealso assessed among 86 severe oligospermic males using sperm DNA. Apart from these, sperm sex chromosomal aneuploidies were analyzed among 20 severe oligospermic and oligoasthenospermic infertile individuals through fluorescence in situhybridization technique. Among 240 infertile individuals assessed 13 (5.4) men were identified to harbour interstitial Y chromosome microdeletions. AZFc region deletions involving DAZgene cluster was observed to be predominant (69.2) followed by AZFb deletions (15.4) and AZFbc deletions (15.4). Statistically significant difference was observed in the Yq deletion frequency between the severe oligospermic and azoospermic individuals (?2 = 4.13, df =1,p=0.042). Germ line specific deletions were observed to be completely lacking among severe oligospermic individuals. Insignificant difference was observed in sperm sex chromosomal aneuploidy rates between the oligospermic and control individuals. Influence of genetic and environmental factors, sampling and methodological differences can be attributed to the differences in Yq deletion frequency observed within Indian populations. Germ cell specific Yq deletions and sperm sex chromosome aneuploidy may not be always associated with severe infertility