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Genetic and Rare Diseases Information Center (GARD)

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Fumarase deficiency

Other Names for this Disease
  • Fumarate hydratase deficiency
  • Fumaric aciduria
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What are the signs and symptoms of fumarase deficiency?

Most newborns with fumarase deficiency show severe neurologic abnormalities, including poor feeding, failure to thrive, and poor muscle tone (hypotonia). Early-onset infantile encephalopathy (altered brain structure or function), seizures, and severe developmental delay with microcephaly are also common. Other signs and symptoms may include infantile spasms, abnormal posturing of the limbs, and autistic features. Distinctive facial features have been reported in some affected individuals and have included an unusually prominent forehead (frontal bossing); low-set ears; a small jaw (micrognathia); widely-spaced eyes (ocular hypertelorism); depressed nasal bridge; and high-arched palate.[1]

Other findings in affected individuals can include neonatal polycythemia (an excess of red blood cells); leukopenia (deficiency of white blood cells); neutropenia; enlarged liver and spleen (hepatosplenomegaly); and pancreatitis.[1]

Many children with this condition do not survive infancy or childhood. Those surviving beyond childhood have severe psychomotor deficits.[1]
Last updated: 11/6/2012

  1. Vivian E Shih and Roseann Mandell. Fumarate Hydratase Deficiency. GeneReviews. June 2, 2009; Accessed 11/6/2012.