Abstract Introduction Cystic Fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene, leading to respiratory infections, poor growth, and malabsorption. While it predominantly affects the white population, it can also occur in other races. There is a concerning trend of missing CF diagnoses in children with respiratory symptoms who have a negative newborn screening (NBS) result, especially in minoritised racial and ethnic groups due to limitations in genetic testing. We present a 3-year-old African American girl who was diagnosed with CF at 2.5 years of age. Case Presentation This case involves a three-year-old African American female who was diagnosed with CF at the age of 2.5 years after a positive sweat test. She was born at 38 weeks with an immunoreactive trypsinogen (IRT) level of 20 ng/ml (normal). She had a history of intermittent cough from seven weeks of age. She was diagnosed with asthma, starting preventive treatment with inhaled corticosteroids due to ongoing symptoms. Due to poorly controlled asthma, a sweat test was performed at 2 years old, revealing intermediate chloride levels of 39 and 45 mmol/L, respectively. Genetic testing for CFTR mutations by sequence analysis and deletion/duplication analysis yielded negative results. Despite treatment, she continued to experience respiratory symptoms, greasy stools, and difficulty gaining weight. A follow-up sweat test revealed positive results (58 and 64 mmol/L), and a fecal elastase test was abnormal (86 µg/g). These findings led to her CF diagnosis, for which she started pancreatic enzyme supplementation and airway clearance therapy, resulting in improved symptoms and weight gain. Additionally, subsequent in-depth CFTR genetic analysis, including intronic analysis, was also negative. Discussion This case highlights the delayed diagnosis of CF in an African American female child who displayed typical symptoms but have a normal NBS result. The implementation of universal NBS for CF in the USA since 2010 has improved diagnosis and outcomes. However, most state genetic panels predominantly reflect mutations in the white population, often overlooking non-white variants. This can lead to false negatives and health disparities, as observed in our patient, who was misdiagnosed with asthma and faced weight gain issues. This case underscores the importance of thorough clinical assessments and timely interventions for managing cystic fibrosis, especially in children. It highlights the need for awareness and improved screening practices that address racial disparities, ensuring equitable healthcare and timely treatment for better health outcomes. This abstract is funded by: NA
Jawaid et al. (Fri,) studied this question.