A fourth case of fumarase deficiency

Fumarate hydratase (fumarase, EC 4.2.1.2) has a key role in cellular energy production: in the mitochondria it is a component of the tricarboxylic acid cycle; in the cytoplasm it is presumably a source of malate for the malate-aspartate shuttle, with an important source of fumarate being the urea cycle. Three cases of proven fumarase deficiency (McKusick 13686) have been reported