Molecular characterization of the cystic fibrosis transmembrane conductance regulator gene in congenital absence of the vas deferens.

PURPOSE

Approximately 20% of patients with congenital absence of the vas deferens remain without two mutations identified. We applied a strategy of serial screening steps to 45 patients with congenital absence of the vas deferens and characterized cystic fibrosis transmembrane conductance regulator gene mutations in all cases.

METHODS

DNA samples of 45 patients with congenital absence of the vas deferens were screened by successive different molecular genetics approaches.

RESULTS

Initial screening for the 31 most frequent cystic fibrosis mutations, IVS8 poly(TG)m, poly(T)n, and M470V polymorphisms, identified 8 different mutations in 40 patients (88.9%). Extensive cystic fibrosis transmembrane conductance regulator gene analysis by denaturing gradient gel electrophoresis, denaturing high-performance liquid chromatography, and DNA sequencing detected 17 further mutations, of which three were novel. Cystic fibrosis transmembrane conductance regulator gene rearrangements were searched by semiquantitative fluorescent multiplex polymerase chain reaction, which detected a CFTRdele2,3 (21 kb) large deletion and confirmed two homozygous mutations. Overall, 42 patients (93.3%) had two mutations and 3 patients (6.7%) had one mutation detected.

CONCLUSIONS

The present screening strategy allowed a higher mutation detection rate than previous studies, with at least one cystic fibrosis transmembrane conductance regulator gene mutation found in all patients with congenital absence of the vas deferens.