How to know if EDS mild classical or EDS hypermobility

My sisters and I all have EDS. Two of us were diagnosed and we know the other has it because her kids have it, but hasn't been diagnosed but has a ton of problems that would indicate having it.
The two of us who were diagnosed were diagnosed with hypermobility type, but I question if we have hypermobility type or mild classical. I ask this because we all scar badly and I get nodules under my skin and little tumors on scars as they develop. Also, my sisters skin is crazy stretchy. She can stretch her skin out about 4 or more inches from her arm. Because there is variable expressivity, how can you know which type it is unless there is a genetic test. In some places I have read that there is a genetic test for classical and other places I have read that there is not. I also read in one place that if you have the hypermobility, but also have the skin manifestations, then it is likely classical because hypermobility type doesn't cause all of those skin problems. Is there a test for mild classical type? Also, does it even matter which type it is as long as it isn't vascular?.

[Jordanna Joaquina, MS, CGC]

You are absolutely correct that it can sometime be difficult to differentiate between types of Ehler-Danlos syndrome (EDS) with very similar manifestations. Sometimes, a diagnosis will be modified if other features, such as significant skin manifestations, present. We recommend that you and your family meet with a medical geneticist, who can perform detailed physical exams and review the family history.  A medical geneticist can be found at the National College of Medical Genetics website.

As you already know, there are multiple types of EDS. Although there are many shared characteristics, the classic type is characterized by wounds that split open and develop wide scars called "cigarette paper" scars. The hypermobility type is characterized by a large range of hypermobility with an absence of significant skin findings (i.e. scarring, major hyperextensibility, and fragility) and soft tissue abnormalities. The skin is often soft or velvety and may be mildly hyperextensible.

There is available genetic testing for the classic type, which looks for mutations in two genes called COL5A1 and COL5A2. However, only 50% of people with the classic form have identifiable mutations in this gene. As such, 50% of people with this form have negative genetic testing.

Currently, there is no available genetic testing for the hypermobility type. Mutations in a gene called TNXB gene have been identified in only a small percentage of families with this form of EDS.

Good luck to you and your family.

[sofa weight]

Thank you for the response. My nephew, I think is going to get tested for marfans, and hopefully the genetecist will decide to test for the eds types. The variability in my family is pretty extreme. One sister you wouldn't think has it, I have fragile connective tissue that tears but my skin doesn't tear much (more than is normal though, I think), and my other sister has really rubbery skin and joints. So, it is hard to tell what is going on with us as to what type. Perhaps my nephew will get tested for classic eds. Otherwise i'll probably be the one to get tested because due to better health coverage.

It is pretty interesting that there is so much variability though just within my family.

I wasn't aware that only 50% of people with classic eds have positive tests.

When they do testing, do they only test for a single type or is there like an eds group of mutations that they look for?