Vascular perfusion abnormalities in infants with spinal muscular atrophy.

Spinal muscular atrophy (SMA) is an important cause of death in children and SMA type I, also known as Werdnig-Hoffman disease, is the most severe form of this disease. We report 2 cases of infants with SMA I in whom a distal necrosis developed, a feature not previously reported. Poor perfusion, autonomic dysfunction, and position-dependent factors may all play a role in the development of this complication.