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

Metachromatic leukodystrophy

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Other Names:
Leukodystrophy metachromatic; Metachromatic leukoencephalopathy; MLD; Leukodystrophy metachromatic; Metachromatic leukoencephalopathy; MLD; Sulfatide lipidosis; Arylsulfatase A deficiency; Cerebral sclerosis diffuse metachromatic form; Cerebroside sulfatase deficiency; ARSA deficiency See More
Categories:
This disease is grouped under:
Metachromatic leukodystrophy is an inherited condition characterized by the accumulation of fats called sulfatides in cells, especially cells of the nervous system. This accumulation results in progressive destruction of white matter of the brain, which consists of nerve fibers covered by myelin. Affected individuals experience progressive deterioration of intellectual functions and motor skills, such as the ability to walk. They also develop loss of sensation in the extremities, incontinence, seizures, paralysis, inability to speak, blindness, and hearing loss. Eventually they lose awareness of their surroundings and become unresponsive. This condition is inherited in an autosomal recessive pattern and is caused by mutations in the ARSA and PSAP genes.[1]

Last updated: 9/19/2014

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.

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Medical Terms Other Names
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HPO ID
80%-99% of people have these symptoms
Ataxia 0001251
Behavioral abnormality
Behavioral changes
Behavioral disorders
Behavioral disturbances
Behavioral problems
Behavioral/psychiatric abnormalities
Behavioural/Psychiatric abnormality
Psychiatric disorders
Psychiatric disturbances
[ more ] 		0000708
Coma 0001259
Decreased nerve conduction velocity 0000762
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood
[ more ] 		0002376
Gait disturbance
Abnormal gait
Abnormal walk
Impaired gait
[ more ] 		0001288
Genu recurvatum
Back knee
Knee hyperextension
[ more ] 		0002816
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Muscle weakness
Muscular weakness
0001324
Neurological speech impairment
Speech disorder
Speech impairment
Speech impediment
[ more ] 		0002167
Peripheral neuropathy 0009830
Seizure 0001250
30%-79% of people have these symptoms
Amaurosis fugax 0100576
Hyperreflexia
Increased reflexes
0001347
Joint stiffness
Stiff joint
Stiff joints
[ more ] 		0001387
Muscular hypotonia
Low or weak muscle tone
0001252
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
Optic atrophy 0000648
Reduced tendon reflexes 0001315
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
5%-29% of people have these symptoms
Aganglionic megacolon
Enlarged colon lacking nerve cells
0002251
Percent of people who have these symptoms is not available through HPO
Abnormality of the cerebral white matter 0002500
Autosomal recessive inheritance 0000007
Babinski sign 0003487
Bulbar palsy 0001283
Cholecystitis
Gallbladder inflammation
0001082
Chorea 0002072
Delusions 0000746
Dysarthria
Difficulty articulating speech
0001260
Dystonia 0001332
EMG: neuropathic changes 0003445
Emotional lability
Emotional instability
0000712
Gallbladder dysfunction 0005609
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ] 		0001290
Hallucinations
Hallucination
Sensory hallucination
[ more ] 		0000738
Hyporeflexia
Decreased reflex response
Decreased reflexes
[ more ] 		0001265
Increased CSF protein 0002922
Loss of speech 0002371
Mental deterioration
Cognitive decline
Cognitive decline, progressive
Intellectual deterioration
Progressive cognitive decline
[ more ] 		0001268
Peripheral demyelination 0011096
Progressive peripheral neuropathy 0007133
Spastic tetraplegia 0002510
Tetraplegia
Paralysis of all four limbs
0002445
Urinary incontinence
Loss of bladder control
0000020
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Last updated: 7/1/2020
Metachromatic leukodystrophy is inherited in an autosomal recessive manner. This means that both copies of the disease-causing gene in each cell must have a mutation for an individual to be affected. Individuals inherit two copies of each gene - one copy from each parent. Typically, an individual is affected because they inherited a mutated copy of the gene from each parent. Individuals with one mutated copy of the gene (such as an unaffected parent of an affected individual) are referred to as carriers; carriers typically do not have any signs or symptoms of the condition.

When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) chance to have the condition, a 50% (1 in 2) chance to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier.
Last updated: 6/28/2012

If someone has a family history of metachromatic leukodystrophy (MLD) or someone is known to be a carrier for MLD, individuals who are biologically related to the affected individual or carrier are at risk to be a carrier. Generally speaking, the more closely related an individual is to the affected individual or carrier, the greater the chance for that person to be a carrier. Prior to genetic testing, the chance to be a carrier for some biological relatives of an affected individual are as follows:

  • Parent of affected individual: assumed to be 100% (called an obligate carrier)
  • Unaffected sibling of affected individual: 2 in 3 (~66.6%)
  • Aunt or uncle of affected individual: 1 in 2 (50%)
  • First cousin of affected individual: 1 in 4 (25%)

If someone has carrier testing and is found to be negative (not a carrier), that person's children are typically assumed to be negative also.

More information about the use of genetic carrier testing is available on GeneTests' Web site and can be viewed by clicking here.

Individuals who are interested in learning about genetic testing and about their specific risk to be a carrier should speak with a genetics professional.

Last updated: 6/28/2012

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.
The prognosis for metachromatic leukodystrophy (MLD) is poor.[2] The late infantile form of the disorder, the most common type, usually appears in the second year of life. This form typically progresses over approximately 5 to 10 years.[3] Most children with the infantile form die by age 5.[2] The juvenile form, with onset between the age of 4 and adolescence, has a slower progression than the late infantile form and symptoms may develop over 10 to 20 years; death typically occurs 10 to 20 years following onset.[2][3] In the adult form, the first symptoms typically appear during the teenage years or later. This form may possibly progress over 20 to 30 years, although many individuals with the adult form die within 6 to 14 years following the onset of symptoms.[2][3] During the progression of this form there may be some periods of relative stability and other periods of more rapid decline.[3]
Last updated: 5/9/2012

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

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 Metachromatic leukodystrophy. 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.

Patient Registry

  • A registry supports research by collecting of information about patients that share something in common, such as being diagnosed with Metachromatic leukodystrophy. The type of data collected can vary from registry to registry and is based on the goals and purpose of that registry. Some registries collect contact information while others collect more detailed medical information. Learn more about registries.

    Registries for Metachromatic leukodystrophy:
    Myelin Disorders Bioregistry Project
    Metachromatic Leukodystrophy Foundation Patient-Powered Registry
     
  • The Lysosomal Disease Network is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with this condition through research. The Lysosomal Disease Network has a registry for patients who wish to be contacted about clinical research opportunities.

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

Organizations Providing General Support

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

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

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 Metachromatic leukodystrophy. 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. Submit a new question

  • My 2 year old grandson has MLD. So both parents are carriers. I have three other children and 2 of them have one child each. All 3 of my other children are planning to have another child. Who in the family needs to be tested for the carrier gene for MLD? Does a child of a carrier automatically become a carrier as well? Will that carrier gene continue to be passed on and should all my family be tested? See answer

  • We found out my cousin has metachromatic leukodystrophy about 8 months ago. He has the adult form. He was having some problems about a year before we found out. I was wondering how long he might have to live and how bad the disease will get over time. See answer


  1. Metachromatic leukodystrophy. Genetics Home Reference. February 2013; http://ghr.nlm.nih.gov/condition/metachromatic-leukodystrophy. Accessed 9/19/2014.
  2. Metachromatic Leukodystrophy Information Page. National Institute of Neurological Disorders and Stroke (NINDS). June 22, 2018; https://www.ninds.nih.gov/Disorders/All-Disorders/Metachromatic-Leukodystrophy-Information-Page.
  3. Metachromatic leukodystrophy. Genetics Home Reference. September 2007; http://ghr.nlm.nih.gov/condition/metachromatic-leukodystrophy. Accessed 5/9/2012.