CFTR and congenital bilateral aplasia of vas deferens from CFTR mutation: In most CBAVD cases, recessive mutations are identified in the cystic fibrosis transmembrane conductance regulator gene (CFTR), and CFTR analysis by sequencing and screening for large rearrangements allows for a mutation detection rate of about 87% in CBAVD patients (Ratbi et al. 2007).