CFTR and congenital bilateral aplasia of vas deferens from CFTR mutation: Pathogenic CFTR (cystic fibrosis transmembrane conduction regulator) gene variants are a cause of cystic fibrosis, CF (OMIM#219700), and CFTR-related disorders (CFTR-RD), particularly, congenital bilateral aplasia of vas deferens (CBAVD) [2,3,4,5].