The cystic fibrosis transmembrane conductance regulator (CFTR) was first identified by positional cloning in 1989, and its mutation was subsequently associated with CF and CAVD (Riordan et al., 1989; Dumur et al., 1990; Anguiano et al., 1992). Here, CFTR is linked to congenital bilateral aplasia of vas deferens from CFTR mutation.