Alpha-methylacyl-CoA racemase deficiency
(often shortened to AMACR deficiency)
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Reviewed December 2013
What is AMACR deficiency?
Alpha-methylacyl-CoA racemase (AMACR) deficiency is a disorder that causes a variety of neurological problems that begin in adulthood and slowly get worse. People with AMACR deficiency may have a gradual loss in intellectual functioning (cognitive decline), seizures, and migraines. They may also have acute episodes of brain dysfunction (encephalopathy) similar to stroke, involving altered consciousness and areas of damage (lesions) in the brain. Other features of AMACR deficiency may include weakness and loss of sensation in the limbs due to nerve damage (sensorimotor neuropathy), muscle stiffness (spasticity), and difficulty coordinating movements (ataxia). Vision problems caused by deterioration of the light-sensitive layer at the back of the eye (the retina) can also occur in this disorder.
How common is AMACR deficiency?
AMACR deficiency is a rare disorder. Its prevalence is unknown. At least 10 cases have been described in the medical literature.
What genes are related to AMACR deficiency?
AMACR deficiency is caused by mutations in the AMACR gene. This gene provides instructions for making an enzyme called alpha-methylacyl-CoA racemase (AMACR).
The AMACR 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.
Most individuals with AMACR deficiency have an AMACR gene mutation that 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.
Read more about the AMACR gene.
How do people inherit AMACR deficiency?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about diagnosis or management of AMACR deficiency?
These resources address the diagnosis or management of AMACR deficiency and may include treatment providers.
- Genetic Testing Registry: Alpha-methylacyl-CoA racemase
- Kennedy Krieger Institute: Peroxisomal
You might also find information on the diagnosis or management of AMACR deficiency in Educational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about AMACR deficiency?
You may find the following resources about AMACR deficiency helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What if I still have specific questions about AMACR deficiency?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
- What does it mean if a disorder seems to run in my family?
- What are the different ways in which a genetic condition can be inherited?
- If a genetic disorder runs in my family, what are the chances that my children will have the condition?
- Why are some genetic conditions more common in particular ethnic groups?
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding AMACR deficiency?
acids ; acute ; ataxia ; autosomal ; autosomal recessive ; cell ; CoA ; deficiency ; digestion ;encephalopathy ; enzyme ; fatty acids ; gene ; mitochondria ; mutation ; nervous system ; neurological ;neuropathy ; peroxisomes ; prevalence ; recessive ; retina ; spasticity ; synthesis ; toxic
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (5 links)
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? in the Handbook.