Hereditary Nasal Parakeratosis

 

Gene: SUV39H2

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:

Labrador retriever mutation: Substitution, SUV39H2 gene; c.972 T>G, p.(N324K), exon4 (Labrador retriever)

Greyhound mutation: Deletion, SUV39H2 gene; c.996+3_996+6 delAAGT

Breed: American Staffordshire Terrier/Amstaff, Australian Cattle Dog, German Shepherd, Greyhound, Labrador Retriever, Saluki

Medical system: Skin

Age of onset of symptoms: 6 to 12 months

Hereditary Nasal Parakeratosis (HNPK) is a genetic condition that affects the skin on the nose of the Labrador retriever.  Due to a defect in the differentiation of the nasal epithelium (superficial layer of the skin), the nose becomes dry and rough with cracks and brownish crusts, resulting in pain, chronic irritation and inflammation.  This condition increases the risks of superficial infection and the nose can eventually lose its pigmentation.  The severity of symptoms varies during the life of the animal.  Apart from these clinical signs, the animal is healthy.  However, it is necessary to administer topical treatment continuously to avoid excessive dryness on the nose.

 

References:

OMIA link: [1373-9615]

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]

Bannoehr J, Balmer P, Stoffel MH, et al. (2020) Abnormal Keratinocyte Differentiation in the Nasal Planum of Labrador Retrievers With Hereditary Nasal Parakeratosis (HNPK)PLoS One 15(3):e0225901. [pubmed/32119674]

Bauer A, Nimmo J, Newman R, et al. (2018) A splice site variant in the SUV39H2 gene in Greyhounds with nasal parakeratosis.  Animal Genetics 49(2) :137-140. [pubmed/29423952]

Jagannathan V, Bannoehr J, Plattet P, et al. (2013) A mutation in the SUV39H2 gene in Labrador retrievers with hereditary nasal parakeratosis (HNPK) provides insights into the epigenetics of keratinocyte differentiation. PLoS Genet. 9(10):e1003848. [pubmed/24098150]

Pagé N, Paradis M, Lapointe JM, Dunstan RW. (2003) Hereditary nasal parakeratosis in Labrador Retrievers. Vet Dermatol. 14(2):103-10. [pubMed/12662268]