Infantile metabolic encephalopathy due to fumarase deficiency.

Fumarase deficiency is a very rare inborn error of metabolism caused by decreased activity of fumarate hydratase enzyme. We describe a fumarase-deficient infant who presented with encephalopathy, metabolic crisis, psychomotor retardation, hypotonia, seizures, and facial dysmorphism. To our knowledge, this is the first Indian child to be described with fumarase deficiency.