National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Adrenomyeloneuropathy

Adrenomyeloneuropathy (AMN) is an inherited condition that affects the spinal cord. It is a form of X-linked adrenoleukodystrophy. On average, people with AMN begin to develop features in the late twenties. Signs and symptoms may include progressive stiffness and weakness of the legs; ataxia; speech difficulties; adrenal insufficiency; sexual dysfunction; and bladder control issues. Some people with AMN also have brain involvement which can lead to behavioral abnormalities, vision loss, hearing problems, and/or seizures.[1][2] AMN is caused by changes (mutations) in the ABCD1 gene and is inherited in an X-linked manner.[3][4] Treatment addresses the symptoms in each person and may include steroid replacement therapy for adrenal insufficiency.[2][4]
Last updated: 2/26/2015
Adrenomyeloneuropathy (AMN) is a form of X-linked adrenoleukodystrophy. On average, people with AMN begin to develop symptoms at age 28; however, the age of onset can range from the second to the fifth decade of life. There are two forms of AMN that vary in severity. The milder form of the condition (AMN without cerebral involvement) only affects the spinal cord, while the more severe form (AMN with cerebral involvement) affects both the brain and the spinal cord.[1]

Signs and symptoms of AMN vary, but may include:[1][2][3]
  • Difficulty walking
  • Changes in gait (style of walking)
  • Progressive stiffness and weakness of the legs
  • Ataxia
  • Hypertonia
  • Speech difficulties
  • Adrenal insufficiency
  • Sexual dysfunction and/or impotence
  • Problems with bladder control
  • Mild peripheral neuropathy
  • Weight loss
  • Nausea
In addition to the symptoms above, people with AMN with cerebral involvement may develop behavioral abnormalities, vision loss, hearing problems and/or seizures.[2]
Last updated: 2/25/2015

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing of 31 |
Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Abnormality of the cerebral white matter 0002500
Alopecia
Hair loss
0001596
Attention deficit hyperactivity disorder
Attention deficit
Attention deficit disorder
Attention deficit-hyperactivity disorder
Attention deficits
Childhood attention deficit/hyperactivity disorder
[ more ] 		0007018
Blindness 0000618
Bowel incontinence
Loss of bowel control
0002607
Bulbar palsy 0001283
Dementia
Dementia, progressive
Progressive dementia
[ more ] 		0000726
Elevated circulating long chain fatty acid concentration 0003455
Hearing impairment
Deafness
Hearing defect
[ more ] 		0000365
Hyperpigmentation of the skin
Patchy darkened skin
0000953
Hypogonadism
Decreased activity of gonads
0000135
Impaired vibration sensation at ankles
Decreased vibration sense at ankles
Decreased vibration sense in feet
[ more ] 		0006938
Impotence
Difficulty getting a full erection
Difficulty getting an erection
[ more ] 		0000802
Incoordination
Difficulties in coordination
Incoordination of limb movements
Limb incoordination
[ more ] 		0002311
Limb ataxia 0002070
Loss of speech 0002371
Lower limb muscle weakness
Lower extremity weakness
Lower limb weakness
Muscle weakness in lower limbs
[ more ] 		0007340
Neurodegeneration
Ongoing loss of nerve cells
0002180
Paraparesis
Partial paralysis of legs
0002385
Polyneuropathy
Peripheral nerve disease
0001271
Primary adrenal insufficiency 0008207
Progressive
Worsens with time
0003676
Psychosis 0000709
Seizure 0001250
Slurred speech 0001350
Spastic paraplegia 0001258
Truncal ataxia
Instability or lack of coordination of central trunk muscles
0002078
Urinary bladder sphincter dysfunction 0002839
Urinary incontinence
Loss of bladder control
0000020
Visual loss
Loss of vision
Vision loss
[ more ] 		0000572
X-linked recessive inheritance 0001419
Showing of 31 |
Last updated: 7/1/2020
Adrenomyeloneuropathy (AMN) is caused by changes (mutations) in the ABCD1 gene. This gene gives the body instructions to make the adrenoleukodystrophy protein (ALDP) which helps transport certain types of fats (called very long-chain fatty acids) into the peroxisomes. Peroxisomes are structures in cells that contain enzymes used to help break down fats and other substances. Mutations in the ABCD1 gene cause low levels of functional ALDP, which then causes high levels of very long-chain fatty acids to build up in the body. High levels of these fats in the nervous system, adrenal glands, and testes disrupt their normal function, resulting in the features of AMN.[3]
Last updated: 2/25/2015
Adrenomyeloneuropathy (AMN) is inherited in an X-linked manner.[4] A condition is considered X-linked if the responsible gene is located on the X chromosome, one of the two sex chromosomes. The Y chromosome is the other sex chromosome. Women have two X chromosomes and men have an X and a Y chromosome.

Because men have one copy of the X chromosome, a mutated copy of the responsible gene in each cell is enough to cause signs or symptoms of the condition. A man with an X-linked condition will pass the mutation to all of his daughters and none of his sons.

Because women have two X chromosomes, the effect of the mutation may be masked by the other, normal copy of the gene, on the other X chromosome. Women with one mutation are often referred to as "carriers" of an X-linked condition. In most cases, carrier women have no symptoms or are mildly affected. However, some may be just as severely affected as males with the condition. Women who carry an X-linked condition have a 50% chance of passing the mutation on with each pregnancy.

In AMN approximately 20% of women who carry one ABCD1 mutation will develop progressive stiffness and weakness in their legs, often in middle age or later. These women typically have normal adrenal function.[4]
Last updated: 2/25/2015
A diagnosis of adrenomyeloneuropathy (AMN) is typically suspected based on the presence of characteristic signs and symptoms. A blood test that measures the levels of a specific type of fat (very long-chain fatty acids) and/or genetic testing for a mutation in the ABCD1 gene can be used to confirm the diagnosis. Once a diagnosis is made, an MRI of the brain may be recommended to determine if the person has AMN with cerebral involvement (brain and spinal cord affected) or AMN without cerebral involvement (only spinal cord affected).[4][1][2]
Last updated: 2/26/2015

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Treatment of adrenomyeloneuropathy (AMN) varies based on the signs and symptoms in each person. For example, steroid replacement therapy may be prescribed in people with adrenal insufficiency. Physical therapy may also be recommended to help build and maintain muscle strength.[1][2][4]
Last updated: 2/26/2015
The long-term outlook (prognosis) for people with adrenomyeloneuropathy (AMN) varies depending on the subtype. In general, AMN with cerebral involvement (both brain and spinal cord affected) has a worse prognosis than AMN without cerebral involvement (only spinal cord affected). Many people without cerebral involvement are able to maintain successful personal and professional lives with physical therapy, management of bladder control issues, and counseling.[1][4]

Approximately 40-45% of people affected by AMN show some degree of brain involvement on MRI. In some of these cases (around 10-20%), the brain involvement becomes severely progressive (worsening over time) and may lead to cognitive decline, behavioral abnormalities, physical disability, or even death.[1][4]
Last updated: 2/26/2015

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnoses include hereditary spastic paraplegias, primary lateral sclerosis, cerebrotendinous xanthomatosis, metachromatic leukodystrophy and Krabbe disease (see these terms) as well as difficiencies in vitamin B12, folic acid or copper. AI symptoms may ressemble Addison Disease (see this term).
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Adrenomyeloneuropathy. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Adrenomyeloneuropathy. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
  • The United Leukodystrophy Foundation has developed an information page on Adrenomyeloneuropathy. Click on the link above to view this information page.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Adrenomyeloneuropathy. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Adrenomyeloneuropathy (AMN). United Leukodystrophy Foundation. http://ulf.org/adrenomyeloneuropathy-amn.
  2. Alan K Percy, MD; Ronald JA Wanders, PhD. Adrenoleukodystrophy. UpToDate. February 2015;
  3. X-linked adrenoleukodystrophy. Genetics Home Reference. July 2013; http://ghr.nlm.nih.gov/condition/x-linked-adrenoleukodystrophy.
  4. Steven J Steinberg, PhD, Ann B Moser, BA, and Gerald V Raymond, MD. X-Linked Adrenoleukodystrophy. GeneReviews. April 2012; http://www.ncbi.nlm.nih.gov/books/NBK1315/.