Cystic fibrosis or not? Familial occurrence of a rare mutation in the CFTR gene.

Cystic fibrosis is a monogenic disease caused by a mutation in the CFTR gene. The classic presentation of the disease includes chronic bronchopulmonary symptoms. However, abnormalities in this gene may also be manifested by other phenotypes, so-called CFTR-related disorders. This is a group of entities including disseminated bronchiectasis, congenital bilateral absence of vas deferens, and chronic pancreatitis. In this article, we present a family with a rare F1052V mutation and a polymorphic variant of IVS-5T+11TG. No classical form of the disease was observed in any of the persons affected by the above changes. Results of special investigations are also not typical, which hinders unequivocal diagnosis.