The CFTR gene mild variants poly-T, TG repeats and M470V detection in Indian men with congenital bilateral absence of vas deferens.

The aim of the study was to detect the frequency of the CFTR gene variants poly-T, TG repeats and c.1408A>G p.Met470Val (M470V) in Indian men with congenital bilateral absence of the vas deferens (CBAVD). Men diagnosed with CBAVD (n = 76), their female partners (n = 76) and healthy men from general population (n = 50) were recruited. Genomic DNA was isolated and the polymorphic regions of IVS9- c.1210-12T [5] and M470V were amplified using specific primers followed by Sanger's DNA sequencing. A statistically significant increase in the frequency of heterozygous IVS9- c.1210-12T [5] (39.4%) was observed in CBAVD men as compared to controls (14%). The allelic distribution of c.1210-12T [5], c.1210-12T [7] and c.1210-12T [9] in CBAVD men was 21%, 64.4% and 13% and that in healthy controls was 7%, 73% and 20% respectively. Longest TG repeat c.1210-34TG [13] was found in association with c.1210-12T [5] with an allelic frequency of 5.9% in CBAVD men. We found a significant association of c.1210-34TG [12]/c.1210-34TG [13] - c.1210-12[5] -V470 allele in CBAVD men. Twelve female partners harboured a heterozygous c.1210-12T [5] allele. The study emphasises the need to screen both partners for the polymorphisms M470V, poly-T, TG tract repeats in addition to population-specific known CFTR gene mutations.