Ichthyose (type Great Dane)

Gene: SLC27A4

Transmission : Autosomal recessive

For an autosomal recessive genetic disease an animal must have two copies of the mutation in question to be at risk of developing the disease.  Both parents of an affected animal must be carriers of at least one copy of the mutation.  Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Substitution (splicing erreur), SLC27A4 gene; c.1250 G>A

Medical system: Skin

Breeds: Great Dane

Age of onset of symptoms: From birth.

Ichthyosis refers to a family of genetic diseases that disrupt normal skin structure and function, giving the skin a scaly appearance. “Ichthy-” refers to fish, as in fish scales. Ichthyosis is a widespread disease in the canine population, with both genetic and environmental factors. In the Great Dane, ichthyosis is a genetic disease caused by mutations within the SLC27A4 gene.  Affected individuals show signs of severe hyperkeratosis, with skin that is thickened, heavily wrinkled, inelastic, lichenified and scaly, particularly around the eyes, nose and distal extremities.  In addition, the scales of the skin lesions have a greasy, whitish to yellowish appearance, particularly on the head and legs. To date, treatment for congenital ichthyosis in Great Danes is symptomatic but not curative. The best treatment for the breed is prevention through genetic testing of breeding animals to identify carriers.

References: 

OMIA link: [1973-9615]

Donner J, Freyer J, Davison S, et al. (2023) Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs.  PLoS Genet. 19(2):e1010651. [pubmed/36848397]

Mauldin EA, Elias PM. (2021) Ichthyosis and hereditary cornification disorders in dogs. Vet Dermatol 32:567-e154. [pubmed/34796560]

Hoffmann A, Metzger J, Wöhlke A, et al. (2016) Congenital ichthyosis in 14 Great Dane puppies with a new presentation. Vet Pathol 53:614-20. [pubmed/26242581]

Metzger J, Wöhlke A, Mischke R, et al. (2015) A novel SLC27A4 splice acceptor site mutation in Great Danes with ichthyosis. PLoS One 10:e0141514. [pubmed/26506231]

Contributed by: Lena Marchand and Laurence Provost, class of 2027, Veterinary Medicine Faculty, University of Montreal.  (Translation: DWS).