The FA2H gene provides instructions for making an enzyme called fatty acid 2-hydroxylase. This enzyme modifies fatty acids, which are building blocks used to make fats (lipids). Specifically, fatty acid 2-hydroxylase adds a single oxygen atom to a hydrogen atom at a particular point on a fatty acid to create a 2-hydroxylated fatty acid. Certain 2-hydroxylated fatty acids are important in forming normal myelin; myelin is the protective covering that insulates nerves and ensures the rapid transmission of nerve impulses. The part of the brain and spinal cord that contains myelin is called white matter.
Health Conditions Related to Genetic Changes
Fatty acid hydroxylase-associated neurodegeneration
At least nine mutations in the FA2H gene have been identified in people with fatty acid hydroxylase-associated neurodegeneration (FAHN). FAHN is a progressive disorder of the nervous system characterized by problems with movement and vision that begin during childhood or adolescence and worsen with age. Brain scans of affected individuals show abnormal accumulation of iron in the brain, especially in a region that is involved in movement.
The FA2H gene mutations that cause FAHN reduce or eliminate the function of the fatty acid 2-hydroxylase enzyme. Reduction of this enzyme's function may result in abnormal myelin that is prone to deterioration (demyelination), leading to a loss of white matter (leukodystrophy). Leukodystrophy is likely involved in the development of the movement problems and other neurological abnormalities that occur in FAHN. Iron accumulation in the brain is probably also involved, although it is unclear how FA2H gene mutations lead to the buildup of iron.
People with FA2H gene mutations and some of the movement problems seen in FAHN were once classified as having a separate disorder called spastic paraplegia 35. People with mutations in this gene resulting in intellectual decline and optic nerve atrophy were said to have a disorder called FA2H-related leukodystrophy. However, these conditions are now generally considered to be forms of FAHN.More About This Health Condition
Other Names for This Gene
- fatty acid alpha-hydroxylase
- fatty acid hydroxylase domain containing 1
- spastic paraplegia 35 (autosomal recessive)
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
- Alderson NL, Rembiesa BM, Walla MD, Bielawska A, Bielawski J, Hama H. The human FA2H gene encodes a fatty acid 2-hydroxylase. J Biol Chem. 2004 Nov 19;279(47):48562-8. Epub 2004 Aug 27. Citation on PubMed
- Dick KJ, Eckhardt M, Paisán-Ruiz C, Alshehhi AA, Proukakis C, Sibtain NA, Maier H, Sharifi R, Patton MA, Bashir W, Koul R, Raeburn S, Gieselmann V, Houlden H, Crosby AH. Mutation of FA2H underlies a complicated form of hereditary spastic paraplegia (SPG35). Hum Mutat. 2010 Apr;31(4):E1251-60. doi: 10.1002/humu.21205. Citation on PubMed
- Edvardson S, Hama H, Shaag A, Gomori JM, Berger I, Soffer D, Korman SH, Taustein I, Saada A, Elpeleg O. Mutations in the fatty acid 2-hydroxylase gene are associated with leukodystrophy with spastic paraparesis and dystonia. Am J Hum Genet. 2008 Nov;83(5):643-8. doi: 10.1016/j.ajhg.2008.10.010. Citation on PubMed or Free article on PubMed Central
- Gregory A, Hayflick SJ. Genetics of neurodegeneration with brain iron accumulation. Curr Neurol Neurosci Rep. 2011 Jun;11(3):254-61. doi: 10.1007/s11910-011-0181-3. Review. Citation on PubMed
- Gregory A, Venkateswaran S, Hayflick SJ. Fatty Acid Hydroxylase-Associated Neurodegeneration. 2011 Jun 28 [updated 2018 Sep 27]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Mirzaa G, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2021. Available from http://www.ncbi.nlm.nih.gov/books/NBK56080/ Citation on PubMed
- Kruer MC, Paisán-Ruiz C, Boddaert N, Yoon MY, Hama H, Gregory A, Malandrini A, Woltjer RL, Munnich A, Gobin S, Polster BJ, Palmeri S, Edvardson S, Hardy J, Houlden H, Hayflick SJ. Defective FA2H leads to a novel form of neurodegeneration with brain iron accumulation (NBIA). Ann Neurol. 2010 Nov;68(5):611-8. doi: 10.1002/ana.22122. Citation on PubMed
- Schneider SA, Bhatia KP. Three faces of the same gene: FA2H links neurodegeneration with brain iron accumulation, leukodystrophies, and hereditary spastic paraplegias. Ann Neurol. 2010 Nov;68(5):575-7. doi: 10.1002/ana.22211. Erratum in: Ann Neurol. 2011 Jul;70(1):187. Citation on PubMed