Junctional Epidermolysis Bullosa in Belgian Draft Horses

The mutation responsible for Junctional Epidermolysis Bullosa (JEB) in Belgian draft horses in North America and other draft breeds in Europe has been identified. The mutation, a cytosine insertion (1368 insC) in the LAMC2 gene, results in absent expression of the laminin γ2 polypeptide chain of laminin 5. JEB is inherited as an autosomal recessive trait. A polymerase chain reaction (PCR) test has been developed to identify carriers of the mutation using mane and tail hairs. Since October 2002, this test has been available to breeders of Belgian horses in the United States and Canada through their breed associations.