Leigh's necrotizing encephalopathy with pyruvate carboxylase deficiency.

Infants with subacute necrotizing encephalopathy or Leigh's encephalopathy usually are first examined before the age of 2 years with degenerative neurologic disease with variable clinical appearance. Necrotizing lesions of the CNS occur with special predilection of the gray matter. Biochemical defects of thiamine triphosphate associated with an inhibitor of the enzyme thiamine pyrophosphate-adenosine triphosphate phosphoryltransferase and deficiency of the enzyme pyruvate carboxylase have been found. Progressive neurologic deterioration and death occurred in an infant with pyruvate carboxylase deficiency. Pathologic studies showed extensive necrotizing areas of the gray matter, mamillary bodies, and midbrain and basal ganglia. Biochemical studies on the liver confirmed a deficiency of pyruvate carboxylase.