Epidermolysis bullosa dystrophica

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Epidermolysis bullosa dystrophica
Classification and external resources
ICD-10 Q81.2
ICD-9 757.39
OMIM 131750
DiseasesDB 29580
MeSH D016108

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.

Classification[edit]

Name Locus & Gene OMIM
Dominant dystrophic epidermolysis bullosa (DDEB)
Also known as "Cockayne-Touraine disease", this variant is characterized by vesicles and bullae on the extensor surfaces of the extremities.[1]:558[2]:601
3p21.3 (COL7A1) 131750
Recessive dystrophic epidermolysis bullosa (RDEB)
Also known as "Hallopeau–Siemens variant of epidermolysis bullosa"[2] and "Hallopeau–Siemens disease",[3] this variant results from mutations in the gene encoding type VII collagen, COL7A1, characterized by debilitating oral lesions that produce pain, scarring, and microstomia.[1]:558–9[2]:601 It is named for François Henri Hallopeau and Hermann Werner Siemens.
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

Causes[edit]

DEB is caused by genetic defects (or mutations) within the human COL7A1 gene encoding the protein type VII collagen (collagen VII).[4] DEB-causing mutations can be either dominant or recessive.

Most families with family members with this condition have distinct mutations.[5]

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[edit]

The deficiency in anchoring fibrils impairs the adherence between the epidermis and the underlying dermis. The skin of DEB patients is thus highly susceptible to severe blistering.

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.

Pathophysiology[edit]

In the absence of mutations of the COL7A1 gene, an autoimmune response against type VII collagen can result in an acquired form of epidermolysis bullosa called epidermolysis bullosa acquisita.[6]

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.[7]

See also[edit]

References[edit]

  1. ^ a b James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0-7216-2921-0.
  2. ^ a b c Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0-07-138076-0.
  3. ^ Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. p. 458. ISBN 1-4160-2999-0. 
  4. ^ 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. 
  5. ^ 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. 
  6. ^ 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. 
  7. ^ 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. 

External links[edit]