Y Chromosome Microdeletions and Partial AZFc Deletions in Infertile Men from South India

Abstract

Aim: Yq microdeletions involving the azoospermia factor (AZF) region are the second most frequent genetic cause of spermatogenic failure next to Klinefelter syndrome. These deletions occur in about 10-15 percent of men with azoospermia and severe oligozoospermia. Molecular screening for AZF deletions has become mandatory in the work-up of infertile men. Further, partial AZFc deletions categorized as gr/gr, b2/b3, b1/b3 and b2/b4 deletions have also been known to affect spermatogenesis. This study aimed to screen for both classical AZF deletions in 250 karyotypically normal infertile men from south India and partial AZFc deletions as a case-control analysis involving 108 fertile men. Methods: PCR amplification involving two multiplex reactions was carried out using primers for six STSs sY84, sY86 (AZFa), sY127, sY134 (AZFb), and sY254, sY255 (AZFc) with two internal controls (SRY, ZFY). Further, those men who showed deletions with one or both STSs sY1291 and sY1191 were subsequently tested with sY1189 and sY1192 to detect partial AZFc deletions.  Results: One individual showed deletion of all the three AZF regions while two men had only AZFc deletion. Deletion of partial AZFb (sY127) was seen besides complete AZFc region in the fourth patient. The gr/gr, b2/b3 and b1/b3 deletions were detected in 24 (9.6%), one (0.4%) and nine (3.6%) infertile men in comparison with five, one and two fertile men respectively. The b2/b4 deletion was observed in a single azoospermic individual. Conclusion: Screening for AZF deletions would help in not only determining the cause for male infertility but also in its management and accurate genetic counselling.