The Ehlers-Danlos syndrome is a heritable connective-tissue disorder caused by defects in fibrillar-collagen metabolism. Mutations in the type V collagen genes account for up to 50 percent of cases of classic Ehlers-Danlos syndrome, but many other cases are unexplained. We investigated whether the deficiency of the tenascins, extracellular-matrix proteins that are highly expressed in connective tissues, was associated with the Ehlers-Danlos syndrome. We screened serum samples from 151 patients with the classic, hypermobility, or vascular types of the Ehlers-Danlos syndrome; 75 patients with psoriasis; 93 patients with rheumatoid arthritis; and 21 healthy persons for the presence of tenascin-X and tenascin-C by enzyme-linked immunosorbent assay. We examined the expression of tenascins and type V collagen in skin by immunohistochemical methods and sequenced the tenascin-X gene. Tenascin-X was present in serum from all normal subjects, all patients with psoriasis, all patients with rheumatoid arthritis, and 146 of 151 patients with the Ehlers-Danlos syndrome. Tenascin-X was absent from the serum of the 5 remaining patients with Ehlers-Danlos syndrome, who were unrelated. Tenascin-X deficiency was confirmed in these patients by analysis of skin fibroblasts and by immunostaining of skin. The expression of tenascin-C and type V collagen was normal in these patients. All five of these patients had hypermobile joints, hyperelastic skin, and easy bruising, without atrophic scarring. Tenascin-X mutations were identified in all tenascin-X-deficient patients; one patient had a homozygous tenascin-X gene deletion, one was heterozygous for the deletion, and three others had homozygous truncating point mutations, confirming a causative role for tenascin-X and a recessive pattern of inheritance. Tenascin-X deficiency causes a clinically distinct, recessive form of the Ehlers-Danlos syndrome. This finding indicates that factors other than the collagens or collagen-processing enzymes can cause the syndrome and suggests a central role for tenascin-X in maintaining the integrity of collagenous matrix.
The Ehlers - Danlos syndrome is a heritable connective - tissue disorder caused by defects in fibrillar - collagen metabolism . Mutations in the type V collagen genes account for up to 50 percent of cases of classic Ehlers - Danlos syndrome , but many other cases are unexplained . We investigated whether the deficiency of the tenascins , extracellular - matrix proteins that are highly expressed in connective tissues , was associated with the Ehlers - Danlos syndrome . We screened serum samples from 151 patients with the classic , hypermobility , or vascular types of the Ehlers - Danlos syndrome ; 75 patients with psoriasis ; 93 patients with rheumatoid arthritis ; and 21 healthy persons for the presence of tenascin - X and tenascin - C by enzyme - linked immunosorbent assay . We examined the expression of tenascins and type V collagen in skin by immunohistochemical methods and sequenced the tenascin - X gene . Tenascin - X was present in serum from all normal subjects , all patients with psoriasis , all patients with rheumatoid arthritis , and 146 of 151 patients with the Ehlers - Danlos syndrome . Tenascin - X was absent from the serum of the 5 remaining patients with Ehlers - Danlos syndrome , who were unrelated . Tenascin - X deficiency was confirmed in these patients by analysis of skin fibroblasts and by immunostaining of skin . The expression of tenascin - C and type V collagen was normal in these patients . All five of these patients had hypermobile joints , hyperelastic skin , and easy bruising , without atrophic scarring . Tenascin - X mutations were identified in all tenascin - X - deficient patients ; one patient had a homozygous tenascin - X gene deletion , one was heterozygous for the deletion , and three others had homozygous truncating point mutations , confirming a causative role for tenascin - X and a recessive pattern of inheritance . Tenascin - X deficiency causes a clinically distinct , recessive form of the Ehlers - Danlos syndrome . This finding indicates that factors other than the collagens or collagen - processing enzymes can cause the syndrome and suggests a central role for tenascin - X in maintaining the integrity of collagenous matrix .
What tissue is most affected in Ehlers-Danlos syndromes?
What tissue is most affected in Ehlers - Danlos syndromes ?
connective tissue
connective-tissue connective tissue