Idiopathic persistent pulmonary hypertension in an infant with Smith-Lemli-Opitz syndrome.

Persistent pulmonary hypertension (PPHN) of the newborn remains a challenging condition to diagnose and treat. It has been reported in infants with Smith-Lemli-Opitz syndrome (SLOS), a rare defect in cholesterol synthesis. Typically, there is evidence of pulmonary hypoplasia. We report the first case of PPHN in the absence of pulmonary hypoplasia or other parenchymal diseases in an infant with SLOS. Perturbations in cholesterol metabolism interrupt key signaling pathways that participate in the normal maintenance of pulmonary vascular tone. We found that caveolae-dependent signaling may be involved in this process since our patient had altered expression of caveolin-1.