Myopathic Ehlers-Danlos Syndrome (mEDS)

mEDS is a genetic connective tissue disorder that causes muscle weakness in infancy and childhood, proximal joint contractures, and distal joint hypermobility.

mEDS is an ultra-rare disorder that affects less than 1 in 1 million people.

mEDS is caused by differences in the genes called genetic variants. These genetic variants affect the connective tissue, which provides support, protection, and structure throughout the body.

mEDS is caused by genetic variants of the COL12A1 gene.

mEDS can be inherited in an autosomal dominant or an autosomal recessive pattern.

An autosomal dominant inheritance pattern means that a condition occurs if a person inherits a genetic variant from one of their parents. Each child of a parent with an autosomal dominant condition will have a 50% chance of having the condition themselves.

An autosomal recessive inheritance pattern means that a condition occurs if a person inherits a genetic variant from both of their parents. People with one copy of the genetic variant are carriers of the condition. Carriers do not have the condition themselves but may pass the genetic variant on to their children. Recessive forms of mEDS are typically more severe than dominant forms of mEDS.

mEDS may be suspected if a person has:

  • Muscle weakness in infancy or childhood
  • Proximal large joint contractures
  • Distal joint hypermobility
  • Delayed gross motor development
  • Congenital kyphosis

If a person meets the diagnostic criteria for mEDS, genetic testing should be done to confirm the diagnosis. Genetic testing is used to see if a person has the genetic variants that cause mEDS.

To meet the diagnostic criteria for mEDS, a person must meet:

  • Major criterion 1 AND at least one other major criterion


  • Major criterion 1 AND at least three minor criteria

Major Criteria 

  1. Congenital muscle hypotonia and/or muscle atrophy that improves with age
  2. Proximal joint contractures (knee, hip, and elbow)
  3. Hypermobility of distal joints

Minor Criteria 

  1. Soft, doughy skin
  2. Atrophic scarring
  3. Motor developmental delay
  4. Myopathy on muscle biopsy

mEDS is managed by addressing the symptoms a person is experiencing. mEDS can cause a variety of symptoms in many different areas of the body, so people with mEDS may require multiple providers in different specialties to manage their care. Key aspects of care include preventing injuries, doing physical therapy, and managing other symptoms. Each person should work with their care team to develop a care plan that meets their individual needs.

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