Fumarase (FH) is an enzyme that catalyzes the reversible hydration/dehydration of fumarate to malate in the mitochondria. Fumarase deficiency is caused by a mutation in the fumarase gene in humans. Fumarase deficiency is one of the few known deficiencies of the Krebs cycle or tricarboxylic acid cycle, the main enzymatic pathway of cellular aerobic respiration.
