N1303K and IVS8-5T, clinical presentation within a family with atypical cystic fibrosis.

The CFTR genotype N1303K/IVS8-5T can cause very mild cystic fibrosis (CF) and congenital bilateral absence of the vas deferens (CBAVD). We report one family consisting of five affected patients in two generations, presenting minor symptoms of CF at different ages, segregating the CFTR mutations N1303K and IVS8-T5-TG13 in trans. Common features were chronic sinopulmonary symptoms and borderline or slightly elevated sweat chloride values. One patient had CBAVD.