However, Yuan et al. in 2019 showed that two CFTR gene mutations in 58.33% (42/72) of Congenital absence of vas deferens (CAVD) patients, only one mutation in 18.06% (13/72) and no mutation in 23.61% (17/72). The gene discussed is CFTR; the disease is congenital bilateral aplasia of vas deferens from CFTR mutation.