The cystic fibrosis transmembrane regulator gene and male infertility

Congenital bilateral absence of the vas deferens (CBAVD) is a relatively fr equent cause of male infertility accounting for 1-2% of cases of male steri lity and at least 6% of cases of obstructive azoospermia. In the last decad e a genetic basis for CBAVD has been provided by its association with cysti c fibrosis (CF) and nowadays CBAVD is in most cases considered to be a mild or incomplete form of CF disease. Many individuals with CBAVD show usually mild CF-compatible clinical manifestations, but the long-term prognosis co uld possibly not be as innocuous as it presently looks: more data will be a vailable through medium or long-term follow-up studies. Once a correct diag nosis of CBAVD has been formulated and if the couple is planning a pregnanc y by artificial reproductive technology, it is crucial to test both the aff ected male and his partner for CFTR mutations. Such testing has a number of complex implications and should always be performed together with genetic counselling. Other issues are debated in this article including CF mutation s in non-CBAVD forms of male infertility, and the potentially misleading ro le of CF genetic analysis when used to rule out other possible causes of in fertility in azoospermic men. (C) 2000, Editrice Kurtis.