800 Mono-Symptomatic Cystic Fibrosis (CF): A Case Report

Abstract

Background: CF is a monogenic disorder with heterogeneous phenotypic presentation. In atypical cases, the sweat test may show border-line or normal values and the diagnosis involves the search for mutations in the CFTR gene, clinical features and follow-up. Aim and clinical Case: We present a case of an adolescent boy affected by recurrent acute pancreatitis (AP) started at puberty, with normal sweat values, carrier of compound heterozygosity (I507del+IVS8(5T)). Attending this result we performed other studies to exclude other possible CFTR-related signs, including respiratory infection and function or azoospermia. The chest radiography, spirometry, semen analysis and ultrasonography of the vas deferens and the seminal vesicles were normal. Tests for pancreatic endocrine and exocrine function were also normal. To complete the genetic evaluation, the siblings and both asymptomatic parents were tested because they are potentially at risk of similar disease. This genetic study showed that the father and the two siblings are carriers of the severe CFTR mutation (I507del) and the mother is carrier of the mutation IVS8 5T. Conclusion: The I507del mutation is a severe CFTR mutation. In contrast, the IVS8(5T) mutation is not associated with clinical cystic fibrosis but, in compound heterozigosity with a more severe mutation, can be causative of mono- or oligosymptomatic CFTR-related disorders. This is probably the first case report of an atypical CF in a patient with the compound heterozygosity I507del+IVS8 5T. It confirms the challenges and difficulties for diagnosing atypical CF and highlights the role of CFTR mutations in the pathogenesis of idiopathic pancreatitis.