Epidermolysis bullosa dystrophica
|Epidermolysis bullosa dystrophica|
|Classification and external resources|
Epidermolysis bullosa dystrophica or Dystrophic EB (DEB) is an inherited disease affecting the skin and other organs. "Butterfly children" is the term given to those born with the disease, as their skin is seen to be as delicate and fragile as that of a butterfly.
|Name||Locus & Gene||OMIM|
|Dominant dystrophic epidermolysis bullosa (DDEB)||3p21.3 (COL7A1)||131750|
|Recessive dystrophic epidermolysis bullosa (RDEB)
||11q22-q23 (COL7A1), 3p21.3 (MMP1)||226600|
|Epidermolysis bullosa dystrophica, pretibial||3p21.3 (COL7A1)||131850|
|Epidermolysis bullosa pruriginosa||3p21.3 (COL7A1)||604129|
|Epidermolysis bullosa with congenital localized absence of skin and deformity of nails||3p21.3 (COL7A1)||132000|
|Transient bullous dermolysis of the newborn (TBDN)||3p21.3 (COL7A1)||131705|
Most families with family members with this condition have distinct mutations.
Collagen VII is a very large molecule (300 kDa) that dimerizes to form a semicircular looping structure: the anchoring fibril. Anchoring fibrils are thought to form a structural link between the epidermal basement membrane and the fibrillar collagens in the upper dermis.
Signs and symptoms
Collagen VII is also associated with the epithelium of the esophageal lining, and DEB patients may suffer from chronic scarring, webbing, and obstruction of the esophagus. Affected individuals are often severely malnourished due to trauma to the oral and esophageal mucosa and require feeding tubes for nutrition. They also suffer from iron-deficiency anemia of uncertain origin, which leads to chronic fatigue.
Open wounds on the skin heal slowly or not at all, often scarring extensively, and are particularly susceptible to infection. Many individuals bathe in a bleach and water mixture to fight off these infections.
The chronic inflammation leads to errors in the DNA of the affected skin cells, which in turn causes squamous cell carcinoma (SCC). The majority of these patients die before the age of 30, either of SCC or complications related to DEB.
There exist other types of inherited epidermolysis bullosa, junctional epidermolysis bullosa and epidermolysis bullosa simplex, which are not related to type VII collagen deficiency. These arise from mutations in the genes encoding other proteins of the epidermis or the basement membrane at the junction between the epidermis and the dermis.
- James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0-7216-2921-0.
- Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0-07-138076-0.
- Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. p. 458. ISBN 1-4160-2999-0.
- Varki R, Sadowski S, Uitto J, Pfendner E (March 2007). "Epidermolysis bullosa. II. Type VII collagen mutations and phenotype–genotype correlations in the dystrophic subtypes". J. Med. Genet. 44 (3): 181–92. doi:10.1136/jmg.2006.045302. PMC 2598021. PMID 16971478.
- Csikós M, Szocs HI, Lászik A et al. (May 2005). "High frequency of the 425A-->G splice-site mutation and novel mutations of the COL7A1 gene in central Europe: significance for future mutation detection strategies in dystrophic epidermolysis bullosa". Br. J. Dermatol. 152 (5): 879–86. doi:10.1111/j.1365-2133.2005.06542.x. PMID 15888141.
- Mihai S, Sitaru C (2007). "Immunopathology and molecular diagnosis of autoimmune bullous diseases". J. Cell. Mol. Med. 11 (3): 462–81. doi:10.1111/j.1582-4934.2007.00033.x. PMID 17521373.
- Fine JD, Eady RA, Bauer EA et al. (2008). "Report of the Third International Consensus Meeting on Diagnosis and Classification of EB". J. Am. Acad. Dermatol. 58 (6): 931–50. doi:10.1016/j.jaad.2008.02.004. PMID 18374450.