CFTR gene mutations and male infertility

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are a relatively frequent cause of male infertility. Depending on the ir molecular consequences, CFTR mutations may either result in typical cyst ic fibrosis (CF), one of the most common autosomal recessive disorders, whi ch is characterized by chronic lung disease, pancreatic exocrine insufficie ncy, an increase in the concentration of sweat electrolytes and male infert ility, due to obstructive azoospermia, or in atypical (often monosymptomati c) forms of CF such as congenital absence of the vas deferens (bi- or unila teral), bilateral ejaculatory duct obstruction or bilateral obstructions wi thin the epididymides. All males with idiopathic obstructive azoospermia be ar an increased risk for CF offspring. Couples requesting microsurgical epi didymal sperm aspiration and in vitro fertilization, e.g. intracytoplasmic sperm injection, should be offered genetic counselling and molecular geneti c analysis of the CFTR gene, if male infertility due to obstructive azoospe rmia is the underlying cause.