Necrotizing encephalopathy and macrocephaly with mitochondrial complex I deficiency.

A neonate presented in the first weeks after birth with vomiting. He was unresponsive, with hypotonia, macrocephaly, and lactic acidosis. The cranial computed tomographic scan revealed a hypodense brain, with increased brain volume and extensive cerebral edema. He died at 6 weeks of age; postmortem examination revealed necrotizing encephalopathy with marked brain edema, spongiosis, thalamic necrosis, and basal ganglia calcifications. Enzyme studies of the mitochondrial respiratory chain revealed complex I deficiency in both muscle and liver.