EDS: Description by Natl Org for Rare Disorders (NORD)

Ehlers Danlos Syndromes – NORD (National Organization for Rare Disorders)

This article, explaining why EDS leads to various kinds of pain, could help your doctor understand why you need such potent pain relievers.

Sometimes, doctors think only about us being extra-flexible (which many of us certainly are not anymore as our joints deteriorate with age) and forget about the wider implications of defective collagen.

The Ehlers-Danlos syndromes (EDS) are a group of related disorders caused by different genetic defects in collagen. Collagen is one of the major structural components of the body.  

Collagen is a tough, fibrous, protein, and serves as a building block essential in both strengthening connective tissue (e.g. bones) and providing flexibility where needed (e.g. cartilage).

The problems seen in patients with EDS can be due to either the poor strength of collagen or to the absence of sufficient amounts of structurally normal collagen.

The primary complications seen in EDS involve the skin, muscles, skeleton, and blood vessels. Patients with EDS often have skin that can be describes as “velvety”, “loose”. This skin characteristic predisposes patients to problems with wound healing. Patients will often note that they develop “paper-thin” scars.

Patients also have excessively flexible, loose joints. These ‘hypermobile’ joints can be easily and frequently dislocated.

Finally, fragile blood vessels leave patients experiencing easy bruising, even an increased tendency to serious episodes of bleeding.

Each subtype of EDS results from a distinct genetic change. Patients within a given, specific subtype share characteristics of disease beyond the primary problems described above, and are covered in detail below.

Signs & Symptoms

Hypermobility type (hEDS)

hEDS (formerly EDSIII) comes with a defined set of complications to be managed but is generally a less severe form of the syndrome. For example, aortic root dilation is usually minimal and does not significantly increase the risk for dissections.

The major complications to patients with hEDS are musculoskeletal in nature.

Frequent joint dislocation and degenerative joint disease are common and associated with a baseline chronic pain, which affects both physical and psychological wellbeing.

Problems with the autonomic nervous system, responsible for regulating body functions and the fight-or-flight response, are common. For example, patients often experience orthostatic intolerance, significant lightheadedness on standing, due to a slowed response by their circulatory system to compensation against blood pressure and flow changes with shifts in body position.

Bowel disorders are also more common with this condition, especially functional dyspepsia (indigestion), and irritable bowel syndrome. Patients with EDS hypermobility type have also frequently reported psychological impairment and mood problems.

Causes

In some individuals, the disorder is due to a spontaneous (de novo) genetic mutation that occurs in the egg or sperm cell. In such situations, the disorder is not inherited from the parents.

So it is possible to have EDS even if no one else in your family does.

Some of the genes associated with EDS provide the instructions on the synthesis of (encode) different subtypes of collagen (COL1A1, COL1A2, COL1A3, COL5A1, and COL5A2). Other genes (ADAMTS2, PLOD1, and TNXB) encode proteins associated with processing collagen or otherwise interacting with collagen. Defects in these genes have been associated with different EDS subtypes.

Hypermobility type (hEDS)

hEDS follows an autosomal dominant inheritance pattern but the causal genes have not yet been identified.

A small number of affected individuals have been found to have a deficiency of tenascin-x, a protein encoded by the gene TNXB. This gene product is found outside the cell and serves in maintaining the integrity of the scaffold in which the collagen lays down. Tenascin-x also functions to regulate the stability of the body’s elastic fibers.

2 thoughts on “EDS: Description by Natl Org for Rare Disorders (NORD)

  1. Rick Cph

    Have you ever considered TNXB for yourself, if you don’t mind me asking? It seems we have very similar histories in terms of onset and problems, and does it matter you think, to know I mean? Hope I’m not being to direct here. And again thank you for the time and effort with the blog.

    Liked by 1 person

    Reply
    1. Zyp Czyk Post author

      I have even blogged about this, but never thought about whether I might have it. I’ll have to look into this more – thanks for the suggestion!

      Like

      Reply

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