Congenital absence of the vas deferens: Cystic fibrosis transmembrane regulatory gene mutations

The role of CFTR channel in female infertility

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-activated trans-membrane ATP gated anion channel present in most epithelia, which transports chloride and bicarbonate ions across the apical membrane. Mutations in the CFTR protein are known to result in defective expression or function, notably the inhibition of chloride and bicarbonate transport. This can result in cystic fibrosis (CF), a disorder characterised by thickness of the mucus lining of the epithelial cells of the alimentary and respiratory tracts, sweat ducts and reproductive organs. As a consequence, there is a reduction in fluid transport at the apical surface. While the most devastating effect of CF is mortality, about 98% of men with CF are infertile, consequent of early blockage of or failure to develop the mesonephrotic ducts as well as the vas deferens. The effect of CF of female fertility is less well-understood. This review highlights the genetics and pathophysiology as well as the mechanism of action of CF on female infertility.