What Your Test Results Mean:

Carriers typically show no symptoms of the disorder; however, carriers are at an increased risk of having a child with JEB. Risk for the current or future pregnancies is dependent on your partner’s carrier status. Carrier testing of your partner is recommended in addition to consultation with a genetic counselor.

Disease Explained:

JEB is an inherited condition in which a subunit of laminin-5 is defective. Laminin-5 is responsible for holding layers of skin together, and when it is non-functional, very fragile and blister easily. Affected individuals have blistering over large areas of their bodies from birth or infancy, including the skin, the mouth, and the digestive tract. Individuals with JEB are very susceptible to infections and may have difficulties with eating and digestion. There is no cure for JEB, and individuals with both the severe Herlitz JEB and more mild non-Herlitz JEB have shortened lifespans.

How the Genetics Works:

LAMB3-related JEB is an autosomal recessive skin disorder caused by pathogenic variants in the LAMB3 gene. In general, individuals have two copies of the LAMB3 gene. Carriers of JEB have a single variant in one copy of the LAMB3 gene while individuals with JEB have variants in both copies of their genes, one inherited from each parent. Risk for two carriers to have a child with the disorder is 25%.