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Dr. DePace, MD, FACC
Within the system of Classical Ehlers-Danlos Syndrome (EDS), there were initially 6 subtypes. However, with the identification of additional genetic and biochemical markers, in 2017 the classification was revised to include 13 types. We previously discussed vascular EDS in greater detail in the last blog. In this blog, we will discuss classical EDS.
With classical EDS, the major diagnostic criteria include skin hyperextensibility, widened atrophic scars, and joint hypermobility. It should be noted that the severity varies even among family members.
Certain proteins called collagen, which provide strength and structure to the extracellular matrix of tissues and organs. The genes that are associated with classical EDS are passed on with autosomal dominant inheritance, which means you only need one parent to get the gene.
Classical Type Ehlers-Danlos Syndrome Criterion
The Major criteria include:
- Skin hyperextensibility and atrophic scarring.
- General hypermobility (a Beighton score of 5 or more)
Minor criteria include:
- Easy bruising
- Soft doughy skin
- Skin Fragility or traumatic splitting
- Mulluscoid pseudotumors, which are fleshy lesions associated with scars at pressure points.
- Subcutaneous spheroids, which are small round hard bodies that are mobile and commonly located on the forearms and chin.
- Hernia or history of hernia
- Epicanthal folds
- Complications of joint hypermobility such as sprains, subluxation, pain, or flexible flat foot.
- First degree relatives who meet clinical criteria.
Minimal criteria suggestive of classical EDS include skin hyperextensibility and atrophic scaring plus generalized joint hypermobility and 3 or more minor criteria.
Genetic confirmation is required for a definitive diagnosis. More than 90% of classical EDS patients labor a mutation of one of the genes that encode for type V collagen. A reduction in type V collagen is central to the pathogenesis of classical EDS.
While musculoskeletal joint hyper-mobility is present in classical EDS, the skin is the key to establishing the diagnosis of classical EDS. The skin is hyperextensible and soft with severe atrophic scarring and hemosiderin deposits, or brown areas over the shin and extensor surfaces, due to easy bruising. Poor wound healing is often seen in classical EDS.
A characteristic facial feature has been described. These are epicanthic folds, excess skin on the eyelids, a prematurely aged appearance, and scars on the forehead and chin. The absence of striae or stretch marks has also been noted in classical EDS patients.
Other problems are gastrointestinal problems, most commonly nausea, vomiting, and gastroesophageal reflux, followed by chronic constipation. Abnormalities in the cornea are also found in classical EDS with thin and steep and transparent corneas.