Junctional Epidermolysis Bullosa (COL17A1)

Junctional epidermolysis bullosa (COL17A1-related) is an autosomal recessive, pan-ethnic disease that is caused by pathogenic variants in the gene COL17A1. This disease can be divided into two forms, known as the Herlitz and non-Herlitz types. The Herlitz type is more severe and is lethal in infancy. Clinical features of both types include fragile skin and mucous membranes that are prone to blistering. In the Herlitz types, blisters may be present at birth, and affected individuals may have frequent infections, electrolyte imbalances, and blood loss. Blisters also occur in the mouth, airway, eyes, and bladder. Recurrent cycles of blistering and healing lead to narrowing of the airway, which may be fatal. In the non-Herlitz type, blistering is more mild and may be localized to certain parts of the body. Some patients do not experience blistering after the newborn period. Some patients may have abnormalities of the nails and hair. Life expectancy is reduced to the first year of life for infants with Herlitz junctional epidermolysis bullosa, but is usually normal in affected individuals with the non-Herlitz type. Most pathogenic variants in the gene COL17A1 cause the non-Herlitz type. Several specific variants in COL17A1 have been reported to cause epithelial recurrent erosion dystrophy, a severe autosomal dominant disorder. No clear genotype-phenotype correlation has been established.

For information about carrier frequency and residual risk, please see the residual risk table.

This gene is included on the following panel(s):