A Missed Cystic Fibrosis Diagnosis in Childhood

We describe a suggestive case of cystic fibrosis (CF) with a CF transmembrane conductance regulator (CFTR) mutation compatible with survival in which the diagnosis was missed in childhood. A 46-year-old man presented to our pediatric hospital with infertility and chronic cough, which had been present since 7 years of age. History was notable for high transaminase levels, hepatic steatosis sinusitis, chronic bronchitis, and duodenal inflammation. A sweat test was performed in duplicate and revealed a near-abnormal chloride level for adult age (77 mEq/L; normal value <72 mEq/L). Significant findings of chronic bronchitis and bronchiectasis were found on x-ray film. A culture of sputum was positive for Pseudomonas aeruginosa. Spirometry showed a severe airflow limitation (FEV₁ 40%, and FVC, 61% of the predicted). CFTR mutation analysis showed the presence of homozygous 3849+10kbct mutation. Among CFTR mutations, 3849+10kbC>T has been reported frequently in adult patients with normal sweat tests and may cause a late diagnosis of CF. We conclude that because the diagnosis of CF might be missed during childhood, the diagnosis of CF in adults should be considered by practitioners, in subjects with chronic respiratory, gastrointestinal, and hepatic complaints.