New data regarding the molecular aspects of the heterogeneous group of epidermolysis bullosa has brought some important information about its pathogenesis. In epidermolysis bullosa simplex the majority of mutations are localized in the genes of the basal cytokeratin 5 (gene KRT5) and 14 (gene KRT14), cytolysis at this layer with intraepidermal blister is seen under light microscopy. Mutations of plectin (gene PLEC1), a protein found in the inner hemidesmosomal plaque, leads also to intraepidermal blisters. In junctional epidermolysis bullosa many proteins from the basal membrane zone are involved, such as laminin 5 (genes LAMA3, LAMB3 and LAMC2), integrin alpha6beta4 (genes ITGA6 and ITGB4) and collagen XVII (gene COL17A1), the dysfunction which leads to a subepidermal blister, at the level of the lamina lucida. In the third group, epidermolysis bullosa dystrophica, the mutations are localized in only one gene (gene COL7A1), where they alter the structure of collagen VII, the principal compound of anchoring fibrils, splitting the skin under the lamina densa. This information can also be used in the prenatal diagnosis of epidermolysis bullosa, with future perspectives of gene therapy.
prenatal diagnosis; epidermolysis bullosa; genetics; biochemical; mutation; polymerase chain reaction
