About Junctional EB

About Junctional EB

Junctional Epidermolysis Bullosa (JEB) is one of the major forms of epidermolysis bullosa, a group of genetic conditions that cause the skin to be very fragile. In individuals affected with JEB, the skin and mucous membranes blister and erode in response to minor injury or friction. This disease is typically classified into two main types: Junctional Herlitz Epidermolysis Bullosa (JEB-H) and Junctional non-Herlitz Epidermolysis Bullosa (JEB-nH). JEB-H is the more severe form of JEB, often leading to death in infancy due to overwhelming infection, malnutrition, electrolyte imbalance, or complications resulting from blistering in the respiratory, gastrointestinal, or genitourinary tract. JEB-nH is less severe, characterized by generalized blistering and mucosal involvement that may be evident at birth or soon after. Although the types differ in severity, their features overlap significantly, and can be caused by underlying mutations in the same gene(s).

The human laminin genes LAMA3, LAMB3, and LAMC2 each express a subunit of the large macromolecule Laminin-332, which plays an important role in strengthening and stabilizing the skin by helping attach the top layer of the skin (epidermis) to the underlying layers. A mutation to a gene encoding a subunit of Laminin-332 results in the production of a defective or non-functional variant of this macromolecule, leading to cells in the epidermis being fragile and easily damaged, causing the skin layers to separate after friction or other minor trauma. While JEB has been shown to result from mutations in any one of LAMA3, LAMB3, or LAMC2, LAMB3 mutations are the most common, causing about 70% of all JEB cases. Our third product, KB107, is in pre-clinical development for the treatment of JEB patients harboring LAMB3 mutations.

For more information on autosomal recessive congenital ichthyosis, visit:
Dystrophic Epidermolysis Research Association of America: http://www.debra.org/junctional