Recurrent Wheezing in a Child: Unraveling Atypical Presentations of Cystic Fibrosis and Polymorphisms: A Case Report

Background: Cystic Fibrosis (CF), is the most common, life-limiting, single-gene disease affecting the Caucasian population, with a reported incidence of1/3500 births. It is inherited in an autosomal recessive fashion and its diagnosis is notably challenging, since in several cases CF may not be detected by the newborn screening test and the sweat test, which are frequently reported negative of with doubtful results, especially in cases with atypical symptoms at onset or with uncommon mutations or polymorphisms. Case Presentation: In this case, we present a case of CF presented with recurrent wheezing, reporting multiple negative or borderline sweat tests. The genetic evaluation revealed delta F508 (CF- causing) and heterozygous poly T5 polymorphism TG11 (TG)11T5. Conclusion: The importance of this case lies in the recognition of wheezing as a symptom and not as a disease, thus many conditions such as CF have to be considered in its diagnostic process. Finally, it is of utmost importance to bear in mind that many mutations or polymorphisms might evade newborn screening and sweat tests.