Recessive dystrophic epidermolysis bullosa in Central Asian Shepherds

Dystrophic epidermolysis bullosa is an inherited skin disorder characterized by the formation of blisters, abrasions, and scars all over the body. The skin is fragile, cornified and hard in places, and very susceptible to damage. Symptoms appear in newborn or very young puppies.

In the Central Asian Shepherd, the disease is caused by a nonsense mutation (c.4579C>T) in the COL7A1 gene, which encodes for collagen type VII. This is normally found in the skin between the epidermis and dermis layers and has an important job in anchoring the two layers of the skin together.

The mode of inheritance of the mutation is probably autosomal recessive. This means that only individuals who inherit the mutated gene from both parents will develop the disease. Carriers of the mutated gene are clinically healthy but pass the mutation on to their offspring. In the case of a mating between two heterozygous individuals, theoretically 25% of the offspring will be completely healthy, 50% of the offspring will be carriers and 25% of the offspring will inherit the mutated gene from both parents and will therefore be affected by the disease.

.

Reference:

Niskanen, J., Dillard, K., Arumilli, M., Salmela, E., Anttila, M., Lohi, H., Hytönen, M.K. : Nonsense variant in COL7A1 causes recessive dystrophic epidermolysis bullosa in Central Asian Shepherd dogs. PLoS One 12:e0177527, 2017. Pubmed reference: 28493971