Hypermobility Syndrome (thing)

Hypermobility Syndrome is not one illness, but rather a collection of genetic conditions which affect the body's connective tissue. Do not be confused by the obvious-looking name. People with HMS are not simply more active or faster moving. They mainly suffer from extremely lax joints and fragile connective tissue (such as tendons, ligaments and muscles). This combination is particularly nasty because an injury which stretches joints (a bad fall for example) will put more strain than normal on the connecting ligaments, tendons and muscles which support the joint. Sufferers of HMS will usually heal slowly (and painfully) following any physical injury or even excessive exertion.

The main Hypermobility Syndromes are...

• Marfan Syndrome
  This disorder is caused by an abnormality on chromosome 15 that inhibits fibrillin production. This causes not only hypermobility in joints, but can also affect all places in the body where fibrillin is important. This includes the skeleton, the cardiovascular system (with possible resulting weakness and leakage in the aorta) and the lungs (which can collapse) and the eyes (retinas often detach). All in all, Marfan Syndrome is pretty dangerous. It only affects 1 in 5000 people, with around ¾ of those affected being genetically prone and ¼ of cases the result of chromosome damage caused by mutation.

• Ehlers-Danlos Syndrome
  Ehlers-Danlos Syndrome, like HMS, is not one condition but actually a family of disorders. These types of EDS include symptoms of hypermobility:
  • Ehlers-Danlos Syndrome Vascular Type (formerly 'EDS Type IV') is a serious and life threatening condition. Similar to Marfan Syndrome in that it affects the cardiovascular system as well as joints. With Vascular EDS it is usually only the small joints (digits) which are affected.
  • EDS Classical Type has many symptoms, including joint hypermobility, limb pain and fatigue.
  • Ehlers-Danlos Syndrome Hypermobility Type (formerly 'EDS Type III') involves symptoms of hypermobility as well as severe musculoskeletal pain.

• Benign Joint Hypermobility Syndrome (BJHS)
  A 'benign' condition because only joints are affected, not the cardio-vascular system as with Marfan Syndrome and some of the types of EDS. According to some experts, BJHS is simply another name for the Hypermobile type of EDS. The debate regarding the differences will probably continue for some time.

All of these conditions are "autosomal dominant" disorders, meaning that if one parent carries the gene, each of their children has a 50% chance of inheriting the gene. Even with the gene, symptoms vary, and children do not always exhibit the same symptoms as their parents.

HMS sufferers are usually advised to take plenty of gentle exercise. With sufficiently good muscle tone the problems associated with HMS are lessened. Stronger muscles can support the lax joints and prevent them being stretched so far, thus lessening damage to the other connective tissues.

Resources

• HMSA (Hypermobility Syndrome Association)
  - http://www.hypermobility.org

• Hypermobility & Fibromyalgia Support Site
  - http://anaiis.tripod.com/hmedfm/id8.html

• Contact a Family - for families with disabled children
  - http://www.cafamily.org.uk/Direct/h56.html

• FocusOnArthritis.com (MedicineNet, Inc) - HMS
  - http://www.focusonarthritis.com/script/main/art.asp?articlekey=390&rd=1