Rapidly progressive pulmonary veno-occlusive disease in an infant with Down syndrome.

A 4-month-old girl with Down syndrome showed unexpected deterioration of pulmonary hypertension. Despite aggressive pulmonary vasodilation therapy, the patient died at 5 months of age. Lung autopsy showed that the pulmonary veins were obliterated by intimal fibrous thickening, and the media of the veins was arterialised with an increase in elastic fibres. Pulmonary veno-occlusive disease should be considered in the management of individuals with Down syndrome.