Junctional epidermolysis bullosa / JEB2 (LAMA3-related) - Horse

What does this test examine?

This genetic test examines the LAMA3 variant that causes JEB2 / junctional epidermolysis bullosa type 2 in horses. The condition is also known as JEB, junctional epidermolysis bullosa, epidermolysis bullosa and a blistering disease of the skin and mucous membranes.

What does junctional epidermolysis bullosa mean?

In JEB, the attachment between layers of the skin is not strong enough. Affected foals can develop blisters, open skin lesions, skin sloughing, painful mucosal lesions and problems around the mouth, coronet band or hooves from birth or shortly after. Lesions can become severe quickly because normal pressure or friction damages the skin.

Practical value of this test

• The test detects the known LAMA3 variant for this form of JEB.
• Carriers are usually healthy themselves, but can pass the variant on.
• Breeders can avoid carrier x carrier matings and prevent affected foals.
• In a suspect foal, the test provides rapid genetic clarity for this specific JEB form.

Inheritance and result

This condition is inherited as an autosomal recessive disorder. A horse with one copy is a carrier. A foal with two copies develops this severe skin and mucous membrane disorder.