CYSTIC-FIBROSIS MUTATION SCREENING IN HEALTHY-MEN WITH REDUCED SPERM QUALITY

The majority of men with cystic fibrosis (CF) are infertile due to a b ilateral congenital absence of the vas deferens (CBAVD). However, clin ically affected CF patients present a spectrum of genital phenotypes r anging from normal fertility to severely impaired spermatogenesis and CBAVD. Recently, it has become apparent that CF can manifest itself as isolated CBAVD in the absence of other clinical symptoms. The present study was undertaken to test the possible involvement of the CF gene in the aetiology of male infertility other than CBAVD. Semen specimens from 127 unrelated healthy males with various diagnoses of reduced sp erm quality were screened for a panel of 13 mutations in the cystic fi brosis transmembrane conductance regulator (CFTR) gene. Fourteen of 80 (17.5%) healthy men with infertility due to reduced sperm quality and 3 of 21 (14.3%) men with azoospermia had at least one CF mutation (on e azoospermic male was a compound heterozygote). The frequency of muta tions in our sample of infertile males was significantly higher than t he expected CF carrier frequency in the local population (P = 0.00139) . No mutations were found in a control group of 26 individuals with no rmal semen parameters. This increased frequency of CF mutations in hea lthy men with reduced sperm quality and in men with azoospermia withou t CBAVD suggests that the CFTR protein may be involved in the process of spermatogenesis or sperm maturation apart from playing a critical r ole in the development of the epididymal glands and the vas deferens.