In this issue of Thorax, Doan et al1 report the clinical and pathological findings from nine paediatric patients with severe acute and chronic lung disease caused by mutations in the ATP-binding cassette A3 protein (ABCA3), a lamellar body-associated transport protein expressed selectively in type II epithelial cells in the alveoli (see page 366). Previous reports regarding the mutations in ABCA3 were derived primarily from the analysis of term infants presenting with severe respiratory failure in the neonatal period.2 3 In the study by Doan et al, five of nine infants had respiratory symptoms at birth but only one died during the neonatal period. The others presented with chronic respiratory signs and symptoms at 3 months to 4 years of age, indicating the marked variability in age and severity of presentation of this genetic disease. These infants generally fail to thrive. Clinical, radiographic and pulmonary function testing were consistent with diffuse alveolar disease. Hypoxaemia and pulmonary function studies indicated severe restrictive lung …