CFTR and cystic fibrosis: It is, therefore, possible that a fair number of subjects are actually CFTR-related disorder (CFTR-RD) (as male infertility in CF is because of Congenital Bilateral Absence of Vas Deferens (CBAVD)) incorrectly labeled as CF, as really the most frequently identified genotype in this group is F508del/5T; TG12.