Ehlers-Danlos Syndrome is an inherited heterogeneous group of thirteen subtypes in which abnormal collagen synthesis affects connective tissue: skin, bones, ligaments, blood vessels, organs and tissue. Collagen is a major structural component of the body. Danish dermatologist Edvard Ehlers recognized the condition in 1901. In 1908, a French physician named Henri-Alexandre Danlos suggested the features of the syndrome. Weak and structurally abnormal collagen may result in flexible and loose joints, poor wound healing, fragile blood vessels, ruptured or prolapsed organs, dysautonomia and many other various health conditions.
The inheritance patterns vary based on each subtype. Autosomal dominant inheritance means that just one copy of an altered gene can produce the disorder. For other subtypes, the disorder can be inherited from one affected parent and some even develop new gene mutations that occur with no family history. The gene mutation for COL1A2 can be found on chromosome seven, altering the collagen found in most connective tissue. This particular gene is associated with cardiac-valvular EDS, atypical Marfan Syndrome and Osteogenesis Imperfecta. There currently is no known gene linked to the most common subtype, hEDS; however, recent testing and research has been launched to discover the gene associated.
The launch collaborated with Ehlers-Danlos Society will collect enough data to gain more knowledge of this rarely diagnosed disorder. Different genes are associated with different subtypes and symptoms can range from mild to life threatening.
For formal diagnosis, a referral to a geneticist is a start. There is test called the Beighton Scale, which has helped assess hypermobility since 1998. Medical history is also important for diagnosis. There is also a list of diagnosis criteria for each subtype that require a patient to meet a certain amount of history and symptoms. Vascular EDS can be potentially fatal, which makes proper diagnosis and subtype classification important.
Ehlers-Danlos Syndrome is not curable but symptoms may be managed with a team of specialists. It is a systemic disorder, meaning that multiple systems may be affected. Many patients see a range of specialists such as pulmonology, electrophysiology, cardiology, gastroenterology, neurology, pain management and so on. Specialists involved depend on the patient’s specific symptomatic issues that are a result of the connective tissue disorder.
The current statistics for the more common subtypes are 1 in 2,500 to 1 in 5,000. Some of the rarer types only have a handful of documented cases. However, recent clinical studies show that EDS is more common and not so much rare as it is rarely diagnosed. This makes awareness, education and advocacy so important, in order to better understand and diagnose this disorder.
References:
The Ehlers-Danlos Society. What Are The Ehlers-Danlos Syndromes? Retrieved from https://www.ehlers-danlos.com/what-is-eds/
National Library of Medicine. (April 2019). Genetics Home Reference: Ehlers-Danlos Syndrome. Retrieved from https://ghr.nlm.nih.gov/condition/ehlers-danlos-syndrome
