Ehlers- Danlos syndrome (EDS) is a family of disorders that cause abnormalities in the synthesis and metabolism of the connective tissue components in skin, bones, blood vessels, joints, and other organs. As a result, the tensile strength and integrity of the affected organs will decrease. EDS is classified into many types according to the symptoms and mode of inheritance. The hypermobility (unusual range of joint movement) type, or type III, is the most common, but the least severe form of EDS that is characterized by musculoskeletal complications, degenerative joint disease, chronic pain, and soft skin. Type III EDS is found to affect 1 in 10,000 to 15,000 people worldwide. Diagnosis of this type of EDS depends mainly on clinical manifestations and family history.
Ehlers-Danlos syndrome (EDS) is inherited as an autosomal dominant disorder; therefore, family history is the most important diagnostic tool. Some people with EDS, hypermobility type have mutations in the Tenascin X (TNXB) gene. The normal product of the TNXB gene is a protein known as tenascin that is important for organizing and maintaining the supportive body tissues. Scientists believe that low tenascin-X levels in the body cause changes in collagen deposition as well as disruption the elastic fiber network in joint ligaments and tendons. A mutation in the COL3A1 gene was reported in a single family with hypermobility EDS.