Classic Ehlers-Danlos syndrome is a heritable connective tissue disorder characterized by skin hyperextensibility, fragile and soft skin, delayed wound healing with formation of atrophic scars, easy bruising, and generalized joint hypermobility. It comprises Ehlers-Danlos syndrome type I and Ehlers-Danlos syndrome type II, but it is now apparent that these form a continuum of clinical findings and differ only in phenotypic severity. It is currently estimated that approximately 50% of patients with a clinical diagnosis of classic Ehlers-Danlos syndrome harbor mutations in the COL5A1 and the COL5A2 gene, encoding the α1 and the α2-chain of type V collagen, respectively. However, because no prospective molecular studies of COL5A1 and COL5A2 have been performed in a clinically well-defined patient group, this number may underestimate the real proportion of patients with classic Ehlers-Danlos syndrome harboring a mutation in one of these genes. In the majority of patients with molecularly characterized classic Ehlers-Danlos syndrome, the disease is caused by a mutation leading to a nonfunctional COL5A1 allele and resulting in haploinsufficiency of type V collagen. A smaller proportion of patients harbor a structural mutation in COL5A1 or COL5A2, causing the production of a functionally defective type V collagen protein. Most mutations identified so far result in a reduced amount of type V collagen in the connective tissues available for collagen fibrillogenesis. Inter- and intrafamilial phenotypic variability is observed, but no genotype-phenotype correlations have been observed. No treatment for the underlying defect is presently available for Ehlers-Danlos syndrome. However, a series of preventive guidelines are applicable.
Classic Ehlers - Danlos syndrome is a heritable connective tissue disorder characterized by skin hyperextensibility , fragile and soft skin , delayed wound healing with formation of atrophic scars , easy bruising , and generalized joint hypermobility . It comprises Ehlers - Danlos syndrome type I and Ehlers - Danlos syndrome type II , but it is now apparent that these form a continuum of clinical findings and differ only in phenotypic severity . It is currently estimated that approximately 50 % of patients with a clinical diagnosis of classic Ehlers - Danlos syndrome harbor mutations in the COL5A1 and the COL5A2 gene , encoding the α1 and the α2-chain of type V collagen , respectively . However , because no prospective molecular studies of COL5A1 and COL5A2 have been performed in a clinically well - defined patient group , this number may underestimate the real proportion of patients with classic Ehlers - Danlos syndrome harboring a mutation in one of these genes . In the majority of patients with molecularly characterized classic Ehlers - Danlos syndrome , the disease is caused by a mutation leading to a nonfunctional COL5A1 allele and resulting in haploinsufficiency of type V collagen . A smaller proportion of patients harbor a structural mutation in COL5A1 or COL5A2 , causing the production of a functionally defective type V collagen protein . Most mutations identified so far result in a reduced amount of type V collagen in the connective tissues available for collagen fibrillogenesis . Inter- and intrafamilial phenotypic variability is observed , but no genotype - phenotype correlations have been observed . No treatment for the underlying defect is presently available for Ehlers - Danlos syndrome . However , a series of preventive guidelines are applicable .
What tissue is most affected in Ehlers-Danlos syndromes?
What tissue is most affected in Ehlers - Danlos syndromes ?
connective tissue
connective tissue