The estimated prevalence of EDS3 worldwide is 1 in 5,000 to 20,000 people. However, the prevalence of all EDS types are at least 1 in 5,000. EDS3 is the most common type. Other types of EDS are more rare, with an incidence of 1 in 40,000.
 

EDS3 is an inherited genetic condition. The exact cause is unknown. In a small percentage of cases, a mutation on the TNXB gene is observed. Mutations on the TNXB gene leads to a reduced level of protein tenascin-X. This changes the way collagen is deposited, and results in problems with the elastic fibers in the joints. Inheritance of the disease follows an autosomal dominant pattern. This means only one copy of the gene needs to be mutated to cause the disorder in an individual.
 

Some common symptoms experienced by patients with EDS3 include hyperextensible and soft skin, spontaneous full or partial dislocations that cause chronic pain, degenerative joint disease, bruising, bowel issues, cardiovascular autonomic dysfunction, and psychological issues. Joint hypermobility is more commonly observed in females and young children. Additional symptoms found in EDS include fatigue, functional gastrointestinal disorders, sleep disturbance, anxiety, depression, dysautonomia, and postural orthostatic tachycardia. However, it must be noted that these conditions are non-specific to EDS.

Many of the symptoms of described above are non-specific for EDS3, making it difficult to diagnose EDS3 based on symptoms. Diagnosis of EDS3 requires an evaluation of clinical characteristics and family history. Three of the following criterias specific to EDS3 must be met for diagnosis:

• Generalized joint hypermobility
• Evidence of syndromic features, musculoskeletal complications, and/or family history
• Exclusion of alternative diagnoses

The Beighton score is used to determine joint hypermobility. Scores of 5 or greater defines generalized joint hypermobility. The diagnostic score required is lower (4 or greater) for individuals aged 50+ and higher (6 or greater) for young children.  
 

Disorder treatments vary depending on the symptoms present. Physical therapy can be used to help strengthen muscles and help with joint stability. In some affected individuals with more severe joint instability, braces, wheelchairs, or other assistive devices may be required. Wheelchairs or scooters can help offload the stress on the lower-extremities. Chronic muscle and bone pain may be managed using pain medications. Lastly, counselling can be useful to help with the psychological and pain associated with the disease.

Depending on the severity of the symptoms experienced by the individual, the prognosis of EDS3 can vary. Life-expectancy is not usually affected. However, quality of life can be affected by chronic pain and joint instability. If symptoms are more severe, they can also impact daily function.

If you are searching for medical advice, specialists in EDS3 can be found through support and advocacy groups, or directories such as the EDS Medical Professionals Directory. Some support groups available to aid individuals and families affected by EDS3 such as:

• EDS Awareness
• Ehlers-Danlos Society
• Ehlers-Danlos Support UK

Hypermobile Ehlers-Danlos Syndrome

Howard P Levy, MD, PhD.

Initial Posting: October 22, 2004; Last Revision: June 21, 2018.

https://www.ncbi.nlm.nih.gov/books/NBK1279/

Hypermobility Syndrome (Joint Hypermobility Syndrome)

Medicine Net

https://www.medicinenet.com/hypermobility_syndrome/article.htm#what_causes_joint_hypermobility_syndrome

Hypermobile Ehlers-Danlos syndrome

National Center for Advancing Translational Sciences

Genetic and Rare Diseases Information Center

https://rarediseases.info.nih.gov/diseases/2081/hypermobile-ehlers-danlos-syndrome

Ehlers-Danlos syndrome, type 3

https://www.ncbi.nlm.nih.gov/gtr/conditions/C0268337/