Contributor: Gordon K. Klintworth
Ehlers-Danlos syndrome is a heterogeneous group of inherited diseases of the connective tissue (collagen, elastin, fibronectin, tenascin) with  abnormalities of the skin, joints, ligaments and blood vessels that are manifest as hyperelasticity, joint hypermobility, tissue fragility, a hemorrhagic diathesis, and bladder diverticula. In this syndrome the skin is stretchable and they may have Gorlin sign. Congenital anomalies of the pulmonary vascular system may occur in Ehlers-Danlos syndrome. Stenotic arterial lesions occur in several conditions (Down syndrome, Ehlers-Danlos syndrome, Alagille syndrome). Pulmonary collapse leading to atelectasis can occur in Ehlers-Danlos syndrome. Persons with Marfan syndrome and Ehlers-Danlos syndrome may develop diverticulosis of the colon at a younger age than usual. Numerous distinct types have been identified based on clinical, genetic and biochemical features: Ehlers-Danlos syndrome type I, Ehlers-Danlos syndrome type II,  Ehlers-Danlos syndrome type III, Ehlers-Danlos syndrome type IV, Ehlers-Danlos syndrome type V, Ehlers-Danlos syndrome type VI, Ehlers-Danlos syndrome type VII, Ehlers-Danlos syndrome type VIII, Ehlers-Danlos syndrome type IX, Ehlers-Danlos syndrome type X, Ehlers-Danlos syndrome type XI. Other examples of the syndrome with an apparent autosomal recessive orautosomal dominant mode of inheritance do not fit into the current classification, including Ehlers-Danlos syndrome - progerioid type, Ehlers-Danlos-like syndrome due to tenascin-X deficiency. Ophthalmologic manifestations are common in Ehlers-Danlos syndrome type VI. Some result from mutations in genes that encode for certain collagens cause Ehlers-Danlos syndrome type I  [COL5A1, COL5A2 or  COL1A1] and Ehlers-Danlos syndrome type III [COL3A1], Ehlers-Danlos syndrome type IV [COL3A1]. Ehlers-Danlos syndrome type X  is associated with a fibronectin abnormality. Mutations encoding the genes for α1 (I) procollagen, α2 (I) procollagen, α1 (III) procollagen, α1 (V) procollagen, α2(V) procollagen and lysyl hydroxylasehave been identified in different types of Ehlers-Danlos syndrome.