Cystic fibrosis, CFTR gene, and male infertility

Abstract

An abnormality of cystic fibrosis transmembrane conductance regulator (CFTR) gene is known to be one of the etiologies of Male infertility. CFTR gene mutations are associated with cystic fibrosis (CF-severe phenotype) to congenital bilateral absence of the vas deferens (CBAVD-mild phenotype). CF is the most common autosomal recessive disorders in the Caucasians, characterized by chronic lung disease, pancreatic insufficiency, rise in sweat chloride, and obstructive azoospermia. The milder phenotype is classified as congenital absence of the vas deferens (bi- or unilateral) (CBAVD or CUAVD) or ejaculatory duct obstruction (EDO). Some of these CAVD cases are associated with unilateral renal anomalies (URA). The role of CFTR gene in this subtype of CBAVD-URA is still not understood clearly. The utility of advanced assisted reproductive technologies such as intracytoplasmic sperm injection (ICSI) helps CBAVD males to become biological fathers. If female partner is CF carrier, there is a risk of having a child with CF or CF-related disorders. The currently available CFTR mutation panels cover the most common mutations of Caucasians. Recent studies conducted in South Asian population suggested different spectrum of CFTR mutations than Caucasians. There is a need to develop population-specific CFTR gene mutation panels especially for South Asians where CF or CF-related disorders were once considered rare.