A Case of Cystic Fibrosis With a Rare Mutation (3849 + 10 kbC > T) and Normal Sweat Chloride Levels

Cystic Fibrosis is an autosomal recessive disorder, which is caused by mutations in CFTR gene on chromosome 7q31.2. The prevalence of CF is approximately 1 in 2500 in Caucasians. In other populations, it has been seen less frequently. Characteristic features include chronic pulmonary disease, pancreatic exocrine insufficiency and secretory systems such as gastro-intestinal and reproductive system function abnormalities. Current guidelines for the diagnosis of CF suggest that a patient must present one or more characteristic phenotypic features or a positive newborn screening test result and a positive sweat test or two CF-causing mutations (1). A screening for CFTR mutations is essential if the sweat test is not conclusive. Here we present a female who was diagnosed with CF at age 1-year with a rare homozygous mutation 3849 + 10 kb C > T and normal sweat chloride concentrations. The proband was a 1-year-old female born to consanguineous parents (Figure 1). She was born at 38 weeks of gestation with a birth weight of 3610 g, birth height of 51 cm and birth head circumference of 37 cm. She was admitted to the hospital at 2 months of age because of respiratory distress syndrome. Her weight was 4700 g (50th percentile), height: 56 cm (75th percentile) and head circumference was 37.5 cm (25th-50th percentile).