Ehlers-Danlos Syndromes are a collection of heritable connective tissue disorders. Either directly or indirectly, EDS is known or thought to alter the biology of collagen in the body (the most abundant protein), which can lead to multi-systemic symptoms or co-morbidities. Each type has certain physical traits and with notable exception to the most common form, hEDS, most types have a known genetic mutatio

Hypermobility Spectrum Disorders are a group of conditions related to joint hypermobiity.  HSD is intended to be diagnosed after other possible answers are excluded, such as EDS, including hypermobile EDS (hEDS).  Information on HSD can be found at  “About HSD”.

There are physical characteristics that are common to all EDS types, including hypermobile joints (joints that move in greater amounts than expected) and skin involvement, such as any of the following: soft, stretchy, saggy, too thin, easy bruising, easy wounding, poor wound healing and/or atrophic scarring.

Each type is a distinct entity and may have very specific and unique features. It is highly improbable to have more than one type of Ehlers-Danlos syndrome, but as they have features and ‘biology’ in common, each type may appear to have variable features of other types.

Ehlers-Danlos Syndromes are classified in a system of 14 subtypes (see below for the 2017 criteria for 13 subtypes). Each EDS subtype has a set of clinical criteria that help guide diagnosis; a patient’s physical signs and symptoms will be matched up to the major and minor criteria to identify the subtype that is the most complete fit.  The 14th type involving unusual variations in the AEBP1 gene was discovered in 2018.

There is substantial symptom overlap between the EDS subtypes and the other connective tissue disorders including hypermobility spectrum disorders, as well as a lot of variability, so a definitive diagnosis for all the EDS subtypes—except for hEDS—also calls for confirmation by testing to identify the responsible variant for the gene affected in each subtype.  Diagnostic criteria are meant solely to distinguish an EDS from other connective tissue disorders, and there are many more possible symptoms for each EDS than there are criteria.  Hypermobile EDS is diagnosed clinically and a checklist of criteria has been developed to assist practitioners, though research is underway to discover hEDS genetic mutations.

For more information, please visit the Ehlers-Danlos Society for additional information on the new classifications, including a useful Q and A handout.