Clinical and demographic characteristics of organic acidaemias in children in a tertiary care hospital in Sri Lanka: A 4-year experience in a single centre

Background: Organic acidaemias (OAs) are a biochemically heterogeneous group of inborn errors of metabolism. They are rare and infrequently reported worldwide. Most OAs are clinically apparent in the neonatal period or early infancy while some can present as a chronic progressive form or even an asymptomatic form. Objectives: To describe the clinical presentation, demographic characteristics and the incidence of OAs in Sri Lankan children. Method: A retrospective descriptive cross-sectional study was conducted over a 4-year period by reviewing records of children suspected of having OAs referred to the Department of Chemical Pathology, Lady Ridgeway Hospital. Demographic information, clinical manifestations, biochemical investigations and mutational results were recorded and analysed using descriptive statistics. Definitive diagnosis was established by gas chromatography and mass spectroscopy (GC-MS) of urine for organic acids. Results: Among the 458 patients suspected, 20 (4.3%) were confirmed to have an OA resulting in an incidence of 13/319,000 live births per year. The mean ages at onset of symptoms and diagnosis were 11.8 months (range; day 1 to 5 years) and 27.1 months (range; day 10 to 12 years) respectively. Among the 20 patients were 5 (25%) with propionic acidaemia and 4 (20%) with beta-ketothiolase deficiency. Nineteen (95%) presented acutely. Common manifestations were respiratory distress in 12 (60%) and persistent or recurrent vomiting in 10 (50%). Learning difficulty, dyskinesia and macrocephaly were some chronic manifestations. Biochemically, 15 (75%) had acidosis and 9 (45%) had ketosis. There were 13 (65%) deaths of which 6 were neonates with acute presentation. Conclusions: Propionic acidaemia and beta-ketothiolase deficiency were the common OAs identified. Common clinical presentations were respiratory distress and persistent or recurrent vomiting. Acidosis was a common biochemical finding.