Published by: The Ehlers-Danlos Society
The Ehlers-Danlos syndromes (EDS) are a group of hereditary disorders of connective tissue that are varied in the ways they affect the body and in their genetic causes. The underlying concern is the abnormal structure or function of collagen and certain allied connective tissue proteins.
They are generally characterized by joint hypermobility (joints that move further than normal range), joint instability (subluxation (partial separation of the articulating surfaces of a joint)) and dislocations (full separation of the surfaces of a joint), scoliosis, and other joint deformities, skin hyperextensibility (skin that can be stretched further than normal) and abnormal scarring, and other structural weakness such as hernias and organ prolapse through the pelvic floor. In the rarer types of EDS, there is also weakness of specific tissues that can lead, for example, to major gum and dental disease, eye disease, cardiac valve and aortic root disorders, and life-threatening abdominal organ, uterine, or blood vessel rupture.
The Ehlers-Danlos syndromes are currently classified into thirteen subtypes. In all but the hypermobile subtype (hEDS) genetics variants have been identified as the cause for the disorder and are part of the diagnostic criteria. Since the publication of the 2017 criteria for EDS a couple of other genes have been identified describing additional new subtypes. In particular, these include AEBP1-related EDS, and a COL1A1/A2 gene variant causing an overlap between EDS and Osteogenesis Imperfecta.
Each EDS subtype has a set of clinical criteria that help guide diagnosis; a patient’s physical signs and symptoms can be matched up to the major and minor criteria to identify the subtype that is the most complete fit. That said, there can be substantial overlap between the EDS subtypes.
Sometimes a “provisional clinical diagnosis” of an EDS subtype is made. This can occur when a person meets a minimal clinical requirement but has no access to molecular confirmation or whose genetic testing shows one or more gene variants of uncertain significance. These individuals should be followed clinically, and alternative diagnoses and expanded molecular testing, skin histology (microscope examination of a skin biopsy), and testing of possibly affected family members should be considered.
Please remember that an individual’s experience with EDS is their own and may not necessarily be the same as another person’s experience. Diagnostic criteria are meant. Click here to read the rest of the story