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Disease Profile

Multiple sclerosis

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)



Immune System Diseases


Multiple sclerosis (MS) is a degenerative disorder that affects the central nervous system, specifically the brain and the spinal cord. The disorder is characterized by destruction of the myelin, the fatty tissue that surrounds and protects the nerve fibers and promotes the transmission of nerve impulses, and damage to nerve cells. The symptoms vary widely from person to person, and may include sensory disturbances in the limbs, problems with muscle control, tremors, muscle stiffness (spasticity), exaggerated reflexes (hyperreflexia), weakness, difficulty walking, poor bladder control, and vision problems. Most patients have periods during which they have symptoms (clinical attacks). The clinical attacks are typically followed by periods without any symptoms (remission). After several years, the symptoms worsen continuously. Multiple sclerosis is considered an autoimmune disorder but the exact cause is unknown. Risk factors for developing multiple sclerosis include genetic factors like changes in the HLA-DRB1 gene and in the IL7R gene and environmental factors, such as exposure to the Epstein-Barr virus, low levels of vitamin D, and smoking. The goal of treatment of MS is to decrease attacks and the inflammation within the central nervous system.[1][2][3]


The peak age of onset is between ages 20 and 40, although it may develop in children and has also been identified in individuals over 60 years of age. The most common signs and symptoms include sensory disturbance of the limbs; partial or complete visual loss; acute and subacute motor dysfunction of the limbs; diplopia (double vision); and gait dysfunction. These signs and symptoms may occur alone or in combination, and have to be present for a minimum of 24 hours to be considered a "clinical attack." The signs and symptoms in individuals with MS are extremely variable, even among affected relatives within families.[2] Symptoms vary because the location and severity of each attack can be different. Episodes can last for days, weeks, or months. These episodes alternate with periods of reduced or no symptoms (remissions). While it is common for the disease to return (relapse), the disease may continue to get worse without periods of remission. Because nerves in any part of the brain or spinal cord may be damaged, patients with multiple sclerosis can have symptoms in many parts of the body.[4]

Muscle symptoms may include loss of balance, muscle spasms, numbness or abnormal sensation in any area, problems moving arms or legs, problems walking, problems with coordination and making small movements, and tremor or weakness in one or more arms or legs. Bowel and bladder symptoms may include constipation and stool leakage, difficulty beginning to urinate, frequent need or strong urge to urinate, and incontinence. Eye symptoms may include double vision, eye discomfort, uncontrollable rapid eye movements, and vision loss. There may be numbness, tingling, or pain in the face, muscles, arms or legs. Other brain and nerve symptoms may include decreased attention span, poor judgment, and memory loss; difficulty reasoning and solving problems; depression or feelings of sadness; dizziness and balance problems; and hearing loss. Individuals may also have slurred or difficult-to-understand speech, trouble chewing and swallowing, and sexual symptoms such as problems with erections or vaginal lubrication.[4]

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.

Medical Terms Other Names
Learn More:
Percent of people who have these symptoms is not available through HPO
CNS demyelination
Double vision
Emotional lability
Emotional instability
Difficulties in coordination
Incoordination of limb movements
Limb incoordination

[ more ]

Multifactorial inheritance
Muscle weakness
Muscular weakness
Pins and needles feeling

[ more ]

Involuntary muscle stiffness, contraction, or spasm
Urinary hesitancy
Difficulty with flow
Urinary incontinence
Loss of bladder control


Studies suggest that there are many factors that influence whether a person will develop multiple sclerosis (MS). The factors that contribute to its onset are multiple and may vary from person to person. The signs and symptoms of MS occur as a result of inflammation, loss of the protective nerve covering (myelin), and the breakdown of nerve cells.[5]

The most widely accepted theory is that MS begins as an autoimmune disorder, where white blood cells (lymphocytes) attack healthy tissues. Later, signs and symptoms occur as a result of abnormal activity of specific cells in the brain and spinal cord (microglial cells) and progressive injury and loss of brain and spinal cord cells.[5]

Additional theories regarding the cause of MS include chronic viral infections and genetic disease. Although many viruses, and particularly the Epstein-Barr virus, have been associated with MS, there is no specific evidence linking viruses directly to the development of MS. Still, Epstein-Barr virus infection is considered a risk factor for the disease.[6] Certain gene changes, including ones in HLA-DRB1 are associated with an increased risk for developing multiple sclerosis. However, it is unclear exactly what role these gene changes play in the development of MS.[5] Having a first-degree relative with MS, like a parent or sibling, does increase a persons risk for the condition (to around 2%). Learn more about gene changes and MS.

Vitamin D is another area of interest. Those who are exposed to more sunlight tend to have higher levels of naturally-produced vitamin D, which is thought to support the immune function and may help protect against immune-mediated diseases like MS.[6]

Further information on the cause of MS is available at the National Multiple Sclerosis Society Web site.


Symptoms of multiple sclerosis (MS) may be similar to those of many other nervous system disorders. The disease is made based on the person's signs and symptoms and is typically diagnosed by ruling out other conditions.[2][4]

"Dissemination in time and space" are commonly-used criteria for diagnosing the relapsing-remitting form of MS (RR-MS). "Dissemination in time means" that there are at least two clinical attacks, each lasting at least 24 hours, separated by at least one month, or a slow, step-wise progressive course for at least six months. "Dissemination in space" means that there are lesions in more than one area of the brain or spinal cord. For primary progressive MS (PP-MS), there are currently no diagnostic criteria that are universally accepted.[2]

Physicians may do many tests to evaluate an individual suspected of having MS.

  • Neurological Exam: May show reduced nerve function in one area of the body or over many parts of the body. This may include abnormal nerve reflexes, decreased ability to move a part of the body, decreased or abnormal sensation, and other loss of nervous system functions.
  • Eye Exam: May show abnormal pupil responses, changes in the visual fields or eye movements, decreased visual acuity, problems with the inside parts of the eye, and rapid eye movements triggered when the eye moves.
  • Other Tests: Lumbar puncture (spinal tap) for cerebrospinal fluid tests, MRI scan of the brain, MRI scan of the spine; nerve function study; and several of blood tests.[4] The Revised McDonald Criteria, published In 2010 by the International Panel on the Diagnosis of Multiple Sclerosis, include specific guidelines for using MRI, visual evoked potentials (VEP) and cerebrospinal fluid analysis to speed the diagnostic process.[1]
  • Treatment

    FDA-Approved Treatments

    The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.


    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

        Learn more

        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

        • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
        • MedlinePlus Genetics contains information on Multiple sclerosis. This website is maintained by the National Library of Medicine.
        • The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers.
        • The National Institute of Neurological Disorders and Stroke (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on 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.

          In-Depth Information

          • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
          • 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. 
          • PubMed is a searchable database of medical literature and lists journal articles that discuss Multiple sclerosis. Click on the link to view a sample search on this topic.

            Press Releases

            • On August 13, 2007, The National Institutes of Health (NIH) posted an article titled Genes Linked to Multiple Sclerosis, which discusses 2 genes that influence the risk of developing multiple sclerosis. Click on the name of the article to read more.


              1. What is Multiple Sclerosis?. National MS Society Web site. https://www.nationalmssociety.org/What-is-MS. Accessed 11/20/2015.
              2. Stüve O, Oksenberg J. Multiple Sclerosis Overview. GeneReviews. May 11, 2010; https://www.ncbi.nlm.nih.gov/books/NBK1316/. Accessed 11/20/2015.
              3. Multiple Sclerosis. Genetics Home Reference. April 2013; https://ghr.nlm.nih.gov/condition/multiple-sclerosis.
              4. Zieve D. Multiple Sclerosis. PubMed Health. August 5, 2010; https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001747/. Accessed 3/30/2011.
              5. Olek MJ, Mowry E. Pathogenesis and epidemiology of multiple sclerosis. In: Gonzalez-Scarano F ed.,. UpToDate. Waltham, MA: UpToDate; Last updated June 2, 2015; Accessed 9/3/2015.
              6. What Causes MS?. National Multiple Sclerosis Society. https://www.nationalmssociety.org/What-is-MS/What-Causes-MS. Accessed 9/3/2015.

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