fumarate hydratase
fu·ma·rate hy·dra·tase
(fū'mă-rāt hī'dră-tās), [MIM*136850]fumarate hydratase
An enzyme encoded by FH on chromosome 1q42.1, which catalyses the reversible hydration of fumarate to S-malate. The mitochondrial isoform is involved in the Krebs (citric acid) cycle; the cytosol isoform is involved in amino-acid-reductive (carboxylation cycle—CO2 fixation) metabolism.Abnormal expression
FH mutations can cause fumarase deficiency and lead to progressive encephalopathy, see table.
Molecular defects
Fumarase deficiency in fetus
Polyhydramnios, brain defects.
Fumarase deficiency in neonate
Severe neurologic defects, poor feeding, failure to thrive, and hypotonia; attributed to defects in the mitochondrial and cytosol isoforms.
Fumarate hydratase germ-line mutations trigger an array of tumours: Uterine leiomyomatosis and renal-cell carcinoma (Reed’s syndrome).