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Genetics Home Reference: your guide to understanding genetic conditions
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AMACR

Reviewed December 2013

What is the official name of the AMACR gene?

The official name of this gene is “alpha-methylacyl-CoA racemase.”

AMACR is the gene's official symbol. The AMACR gene is also known by other names, listed below.

What is the normal function of the AMACR gene?

The AMACR gene provides instructions for making an enzyme called alpha-methylacyl-CoA racemase (AMACR). This enzyme is found in the energy-producing centers in cells (mitochondria) and in cell structures called peroxisomes. Peroxisomes contain a variety of enzymes that break down many different substances, including fatty acids and certain toxic compounds. They are also important for the production (synthesis) of fats (lipids) used in digestion and in the nervous system.

In peroxisomes, the AMACR enzyme plays a role in the breakdown of a fatty acid called pristanic acid, which comes from meat and dairy foods in the diet. In mitochondria, AMACR is thought to help further break down the molecules derived from pristanic acid.

How are changes in the AMACR gene related to health conditions?

alpha-methylacyl-CoA racemase deficiency - caused by mutations in the AMACR gene

Alpha-methylacyl-CoA racemase (AMACR) deficiency is caused by mutations in the AMACR gene. This disorder leads to a variety of neurological problems that begin in adulthood, including gradual loss in intellectual functioning (cognitive decline), seizures, and weakness and loss of sensation in the limbs due to nerve damage (sensorimotor neuropathy). Most individuals with AMACR deficiency have an AMACR gene mutation that replaces a protein building block (amino acid) called serine with an amino acid called proline at position 52 in the enzyme sequence, written as Ser52Pro or S52P. This mutation results in a lack (deficiency) of functional enzyme. The enzyme deficiency leads to accumulation of pristanic acid in the blood. However, it is unclear how this accumulation is related to the specific signs and symptoms of AMACR deficiency.

other disorders - caused by mutations in the AMACR gene

AMACR gene mutations that result in a lack of functional AMACR enzyme have also been identified in infants with a life-threatening disorder called congenital bile acid synthesis defect type 4. Babies with this disorder have cholestasis, which is a reduced ability to produce and release a digestive fluid called bile. Cholestasis leads to an enlarged liver (hepatomegaly) and irreversible liver disease (cirrhosis) in the first few months of life.

Some researchers consider congenital bile acid synthesis defect type 4 and AMACR deficiency (see above) to be variations of the same disorder. Because most individuals with congenital bile acid synthesis defect type 4 do not survive infancy, it is unclear whether they would have later developed the neurological symptoms seen in adults with AMACR deficiency.

Where is the AMACR gene located?

Cytogenetic Location: 5p13

Molecular Location on chromosome 5: base pairs 33,986,985 to 34,008,114

The AMACR gene is located on the short (p) arm of chromosome 5 at position 13.

The AMACR gene is located on the short (p) arm of chromosome 5 at position 13.

More precisely, the AMACR gene is located from base pair 33,986,985 to base pair 34,008,114 on chromosome 5.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about AMACR?

You and your healthcare professional may find the following resources about AMACR helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the AMACR gene or gene products?

  • 2-methylacyl-CoA racemase
  • AMACRD
  • AMACR_HUMAN
  • CBAS4
  • RACE
  • RM

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding AMACR?

acids ; amino acid ; bile ; breakdown ; cell ; cirrhosis ; CoA ; congenital ; deficiency ; digestion ; digestive ; enzyme ; fatty acids ; gene ; mitochondria ; mutation ; nervous system ; neurological ; neuropathy ; peroxisomes ; proline ; protein ; serine ; synthesis ; toxic

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • OMIM: ALPHA-METHYLACYL-CoA RACEMASE (http://omim.org/entry/604489)
  • Dick D, Horvath R, Chinnery PF. AMACR mutations cause late-onset autosomal recessive cerebellar ataxia. Neurology. 2011 May 17;76(20):1768-70. doi: 10.1212/WNL.0b013e31821a4484. (http://www.ncbi.nlm.nih.gov/pubmed/21576695?dopt=Abstract)
  • Ferdinandusse S, Denis S, Clayton PT, Graham A, Rees JE, Allen JT, McLean BN, Brown AY, Vreken P, Waterham HR, Wanders RJ. Mutations in the gene encoding peroxisomal alpha-methylacyl-CoA racemase cause adult-onset sensory motor neuropathy. Nat Genet. 2000 Feb;24(2):188-91. (http://www.ncbi.nlm.nih.gov/pubmed/10655068?dopt=Abstract)
  • Ferdinandusse S, Denis S, IJlst L, Dacremont G, Waterham HR, Wanders RJ. Subcellular localization and physiological role of alpha-methylacyl-CoA racemase. J Lipid Res. 2000 Nov;41(11):1890-6. (http://www.ncbi.nlm.nih.gov/pubmed/11060359?dopt=Abstract)
  • Haugarvoll K, Johansson S, Tzoulis C, Haukanes BI, Bredrup C, Neckelmann G, Boman H, Knappskog PM, Bindoff LA. MRI characterisation of adult onset alpha-methylacyl-coA racemase deficiency diagnosed by exome sequencing. Orphanet J Rare Dis. 2013 Jan 3;8:1. doi: 10.1186/1750-1172-8-1. (http://www.ncbi.nlm.nih.gov/pubmed/23286897?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/23600)
  • Wierzbicki AS. Peroxisomal disorders affecting phytanic acid alpha-oxidation: a review. Biochem Soc Trans. 2007 Nov;35(Pt 5):881-6. Review. (http://www.ncbi.nlm.nih.gov/pubmed/17956237?dopt=Abstract)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: December 2013
Published: December 22, 2014