From OMIMGeneralized severe epidermolysis bullosa simplex-1A (EBS1A) is an autosomal dominant skin disorder characterized by generalized intraepidermal skin blistering from minimal mechanical trauma beginning at birth. A herpetiform (arcuate) pattern of blisters, a crusting-necrotic aspect of the lesions that is often associated with inflammatory plaques, and clumping of keratin intermediate filaments seen on electron microscopy define the severe subtype of EBS. Skin fragility is very prominent at birth, and large tense blisters can occur after minimal trauma or spontaneously; the disorder may be life-threatening in the first year of life. Congenital ulcerated areas on hands and feet as well as nail involvement are common. Blistering is exacerbated by heat, humidity, and sweating. Tendency to blistering diminishes in adolescence (summary by Has et al., 2020).
Epidermolysis bullosa simplex (EBS) comprises a group of clinically and genetically heterogeneous skin disorders characterized by recurrent blistering of the skin following minor physical trauma as a result of cytolysis within basal epidermal cells. Most forms show autosomal dominant inheritance. The severe subtype of EBS was previously known as the Dowling-Meara type. The other 2 main subtypes of EBS are the generalized intermediate, previously known as Koebner, type (see 131900) and the localized, previously known as Weber-Cockayne, type (see 131800) (Fine et al., 2008). All 3 of these main subtypes can be caused by mutation in either the KRT5 or the KRT14 gene. Rare EBS subtypes are clinically and genetically heterogeneous and include several syndromic types.
Other types of epidermis bullosa (EB), classified by the level of skin cleavage and other ultrastructural laboratory findings in addition to clinical features, are junctional EB (JEB; see 226700) and dystrophic EB (DEB; see 131750).
Genetic Heterogeneity of Epidermolysis Bullosa Simplex
Other forms of EBS that are caused by mutation in the KRT14 gene are generalized intermediate EBS1B (131900), previously known as the Koebner type; localized EBS1C (131800), previously known as the Weber-Cockayne type; and autosomal recessive generalized EBS1D (601001).
Forms of EBS caused by mutation in the KRT5 gene are generalized severe EBS2A (619555); generalized intermediate EBS2B (619588); localized EBS2C (619594); generalized autosomal recessive EBS2D (619599); EBS2E (609352), with migratory circinate erythema; and EBS2F (131960), with mottled pigmentation.
EBS3 (615425) is caused by mutation in the DST gene (113810). EBS4 (615028) is caused by mutation in the EXPH5 gene (612878).
Forms of EBS caused by mutation in the PLEC gene (601282) are EBS5A (131950), Ogna type; EBS5B (226670), with muscular dystrophy; EBS5C (612138), with pyloric atresia; and EBS5D (616487), autosomal recessive generalized intermediate.
EBS6 (617294), with scarring and hair loss, is caused by mutation in the KLHL24 gene (611295).
EBS7 (609057), with nephropathy and deafness, is caused by mutation in the CD151 gene (602243).
Reviews
Has et al. (2020) reviewed characteristic features and molecular bases of the subtypes of epidermolysis bullosa, and provided a consensus reclassification of disorders with skin fragility.
Fine et al. (2008) reviewed phenotypic features and molecular bases of all epidermolysis bullosa subtypes, and recommended revisions in the classification system.
http://www.omim.org/entry/131760