HERDA / hereditary equine regional dermal asthenia (PPIB-related) - Horse

What does this test examine?

This genetic test examines the PPIB c.115G>A variant in horses. The condition is known as HERDA, hereditary equine regional dermal asthenia, hyperelastosis cutis and collagen-related skin fragility.

What does this mean for the horse?

PPIB is involved in normal collagen folding and structure. Horses with two copies of the variant develop skin that is too stretchy and fragile. The skin can tear easily, especially over the back, withers and saddle area. Wounds often heal slowly and scarring can be marked. The condition often becomes obvious when young horses enter training or are started under saddle.

Practical value of this test

• The test identifies clear horses, carriers and genetically affected horses for HERDA.
• Breeders can avoid carrier-to-carrier matings and prevent affected foals.
• The result is especially useful in Quarter Horse-related lines where the variant occurs.

Inheritance

HERDA is inherited as an autosomal recessive trait. Carriers have one copy and generally do not develop the condition; horses with two copies develop HERDA.