SummaryWe present a three-year-old girl with respiratory failure due to hereditary pulmonary alveolar proteinosis caused by abnormal alpha chain of the granulocyte-macrophage colony-stimulating factor receptor. Both the patient and an asymptomatic seven-year-old sister were homozygous for the same mutation in CSF2RA. We speculate that the Mycoplasma pneumoniae pneumonia might have triggered the clinical presentation. While a good response to serial partial lung lavage was noticed, the ultimate outcome is uncertain
