Hereditary blistering disorders of the skin are found with varying severity in both humans and animals. A symptom typical of all disease types is fragile skin that is easily damaged, followed by blistering and abrasion of the skin. This is caused by a defect in or deficiency of the structural proteins of the skin.
“The project got its start when blistering in the skin and mucosal membranes was detected in different parts of the body in newborn littermates of Central Asian Shepherd dogs. This finding aroused suspicions of a hereditary blistering disorder of the skin,” says researcher Marjo Hytönen, a member of the research group led by Professor Hannes Lohi.
Pathological tests conducted by the Finnish Food Safety Authority Evira confirmed the diagnosis as epidermolysis bullosa. In genetic studies conducted by gene researchers at the University of Helsinki, the gene defect causing the disease was found in the COL7A1 gene. The gene is responsible for producing collagen, an important component in preserving the elasticity of the skin. This finding helped specify the diagnosis as the dystrophic form of the recessive blistering disorder of the skin known as epidermolysis bullosa. Four different structural types of the disease are known: simplex, junctional, dystrophic and Kindler syndrome.
“Immunostaining conducted with skin samples collected from dogs with the disorder proved that the functional form of the protein, or collagen, was absent from the skin of these dogs,” says Kati Dillard, a veterinarian at the Finnish Food Safety Authority Evira.
“Collagen has an important job in anchoring the two layers of the skin together. Due to the absence of the functioning protein, the skin layers are easily detached,” clarifies Julia Niskanen, a researcher at the University of Helsinki.
Identifying the gene defect enables the identification of those dogs used for breeding that carry the defect, which, in turn, makes it possible to effectively eradicate the disorder from the entire breed.
The research group responsible for the project, led by Professor Hannes Lohi, operates as part of the Faculties of Veterinary Medicine and Medicine at the University of Helsinki, as well as the Folkhälsan Research Center. The study was financed by the Academy of Finland, the Jane and Aatos Erkko Foundation, Biocentrum Helsinki, the Orion Research Foundation, the Morris Animal Foundation, as well as the Jenny and Antti Wihuri Foundation.
The study was published in the PLOS ONE journal on 11 May 2017:
Julia Niskanen, Kati Dillard, Meharji Arumilli, Elina Salmela, Marjukka Anttila, Hannes Lohi, Marjo K. Hytönen. (2017) Nonsense variant in COL7A1 causes recessive dystrophic epidermolysis bullosa in Central Asian Shepherd Dogs. PLOS ONE, https://doi.org/10.1371/journal.pone.0177527
Marjo Hytönen, firstname.lastname@example.org, puh. 02941 25779
Hannes Lohi, email@example.com, puh. 02941 25085