The Types of EDS

If you’ve read my page ‘What is EDS?‘ you’ll have learned that there are 7 main types of Ehlers-Danlos. Each type is a distinct disorder and can be traced to a slightly different mutation relating to the production or usage of collagen within the body with the exception of the Hypermobile Type for which the faulty gene has as yet has not been isolated. EDS types “run true” in a family. This means that an individual with Vascular EDS will not normally have a child with Classical Type EDS.
EDS types are defined according to the signs and symptoms that are manifested, in a set of major and minor diagnostic criteria for each type. I have included the table of criteria further down this post.

The seven main types are:

  • Classical (old types I & II)
    This type is distinguished by it’s extensive skin involvement. Marked skin hyperextensibility (stretchy skin), soft velvety texture with widened paper-like scars and joint hypermobility. When all diagnostic criteria are met this type is 90% due to a mutation in type 5 collagen. Some people however have a clinical diagnosis of Classical type and have an as yet unknown gene.
  • Hypermobile (old type III/3)
    The most common form of Ehlers-Danlos, most people with EDS have this type. It’s not actually all that rare but it is very much mis &under-diagnosed.
    Joint hypermobility is the dominant symptom in this type with recurring subluxations and dislocations being common. Skin may have some mild involvement eg. velvety texture and easy bruising but is rarely as stretchy as in the Classical Type. Many patients suffer chronic pain. This type when severe is frequently disabling and can produce milder forms of the symptoms more usually associated with other types.
    dnaNo genetic cause has been located as yet but the syndrome however a small sub-population of less than 10% have been shown to have Tenascin-X deficiency (TNXB gene). Hypermobile Type is inherited following a dominant pattern.
    There is some discussion in the medical community as to whether Joint Hypermobility Syndrome may be a milder form of Hypermobile EDS. I agree that some patients with a JHS diagnosis almost certainly do have EDS but others really do not. They have acquired or bio-mechanical hypermobility meaning the JHS diagnosis is still required. Doctors just need to learn to separate out those with connective tissue problems from those without.
  • Vascular (old type IV/4)
    This is generally regarded as the most serious form of EDS and is the only form of EDS that can affect life expectancy. Arterial/venous and organ fragility is the hallmark of this type and unfortunately many people do not discover that they have it until they suffer a serious rupture or worse. This type often has few outward signs other than extensive bruising after only minor traumas and thin skin which reveals the pattern of the vasculature. Clinicians used to think that Vascular type patients all had a particular look to them but as more people have been diagnosed this has turned out not to be true (information from Dr. Brad Tinkle). This type is caused by mutations on the gene for type 3 collagen.
  • Kyphoscoliosis (old type VI/6)
    This type is marked out by a progressive scoliosis, sufferers are hypermobile and often have extremely low muscle tone from birth which can affect gross motor skills.  This type is the result of a deficiency of lysylhydroxylase (caused by a mutation on the PLOD gene) which is a collagen-modifying enzyme and is inherited in a recessive pattern.
  • Arthrochalasia (old type VIIa&b/7a&b)
    This type is marked out by congenital (at birth) bilateral (both sides) hip dislocation and short stature. Generalised hypermobility with recurrent subluxations and dislocations, scoliosis and skin manifestations.Individuals with this type are very rare, there are less than 50 known cases worldwide, it is caused by mutations to type 1 collagen.
  • Dermatosparaxis (old type VIIc/7c)
    This type is characterised by sagging, redundant skin. The skin is very fragile but wounds heal normally unlike in the Classical Type. Patients bruise very easily. This is another very rare type with not many cases reported worldwide. It is caused by a mutation on the ADAMTS-2 gene which produces pro-collagen peptidase, an enzyme that aids in the processing of type I pro-collagen.
1997 Villefranche Criteria for EDS

Since the types were last classified at Villefranche in 1997 some more types have been described but their names are not yet official and there are no set diagnostic criteria to help doctors diagnose them.
Examples of these syndromes include progeroid type (B4GALT7 gene), musculocontractural type  (CHST14 gene) and spondylocheirodyplastic type.
Prior to 1997 the types were classified with numbers shown as roman numerals rather than names, some people and doctors still use these old classification numbers.

I hope this post has been helpful in explaining the wide variety of EDS types. Each type can be expressed on a spectrum from mild through to severe. Why some patients are more greatly affected than others is sometimes due to the form of their mutation as in the Vascular type but is usually unknown.

If you have any questions please do pop them in the comments and I’ll do my best to answer them but remember I am just a patient not a doctor or geneticist!

Bendy Investigates: What is Collagen?

investigates500We often hear skin creams and treatments making claims about collagen and claims are made about dietary collagen supplements. But what exactly is it?

Collagen is the most abundant protein in the body and is the substance that holds the whole body together. It is found in the bones, teeth, muscles, skin and tendons, and even our hair where it forms a scaffold to provide strength and structure. This is why when collagen production is disrupted in some way as it is in those with Ehlers-Danlos syndrome or Osteogenesis Imperfecta (more commonly known as brittle bone disease) it causes such wide ranging and disabling symptoms.

There are at least sixteen different types of collagen but types I-V make up the majority of the body. In the majority of collagen types, the molecules are packed together to form very similar long thin fibrils (very fine fibres). Type I collagen is particularly strong is found in the bones and teeth, this is the form affected in Osteogenesis Imperfecta.

Collagen in Skincare

In the middle layer of the skin – the dermis – collagen helps form a fibrous network, upon which new cells can grow. This collagen network naturally declines with age and is also thought to change shape, which reduces the structural integrity of the skin leading to sagging and the formation of lines and wrinkles.
mythMany brands have jumped on the collagen bandwagon and produced products containing collagen. Everything from gels to creams and powders, claim to rejuvenate skin and fill wrinkles. However, despite the glossy marketing of these products collagen molecules themselves are simply too big to be absorbed through the skin.If any benefits are derived from these lotions and potions it is most likely to be from the moisturising components of the formulation or perhaps something like hyaluronic acid.
You can look after your skin and protect it’s collagen by not smoking, consuming too much sugar, and being sure to wear your SPF when out in the sun.

factCollagen is however used successfully in more invasive cosmetic procedures such as dermal fillers. These are injections of collagen which can improve the contours of the skin and fill out any depressions. Light therapy at certain wavelengths is also thought to help stimulate collagen production and is used to treat scarring and stretch marks.
Collagen is also used in the medical field as a healing aid for burns and in reconstructive surgeries.

Can’t You Just Take Collagen Supplements?

This is something that gets asked a lot but there is a very simple reason why it won’t work. Collagen as a molecule is too large to be absorbed whole through the gut as well as through the skin, so in order for a supplement to be worthwhile taking the collagen must be broken down into smaller chunks at which point you are in fact supplementing the amino acids required for building collagen, not collagen its self. Since the bodies of those of us with collagen related syndromes can only make the collagens they have the ‘recipe’ for, this is what they will make from these amino acids. They are selling you extremely over-priced gelatin.
Trials have found no benefit to arthritis sufferers when taking these supplements and of course they don’t even have the problem of their body producing faulty collagen.

collagenI hope you’ve found this topic as interesting as I did, it was nice for me that there was some crossover between the beauty/skin care aspects here as well as the EDS related parts plus I got to do a bit of myth de-bunking. My favourite!

If you have any questions of additions do pop them in the comments, I’d love to read them.

It’s EDS Awareness Month!

Media Pack

May the 1st is the start of Ehlers-Danlos Syndrome awareness month!

Media Pack

Throughout May I’ll be doing posts about EDS. I’l be covering the different types of EDS, where the zebra comes from, fibromyalgia awareness day, the HMSA and their work with all of the hypermobility causing syndromes, and I hope to have a guest post from a friend with one of the rarer types of EDS for you too!

You know your condition needs more awareness when most doctors have never heard of it! I nearly always have to spell it for a new doctor and I’ve had doctors Google it on their iPhones in front of me.

If you have EDS, do you have anything planned for May awareness?