Hereditary nasal parakeratosis is an inherited, recessive genetic defect that affects specialized cells of the canine nose, resulting in the formation of a crust with cracks over the nasal area of young dogs.
Phenotype: Hereditary nasal parakeratosis affects specialized cells of the nose, resulting in the formation of a crust with cracks over the nasal area of young dogs. Affected dogs are otherwise healthy, although leaked fluid tends to accumulate in the cracks.
Mode of Inheritance:Autosomal recessive
Alleles: N = Normal, H = Hereditary nasal parakeratosis
Breeds appropriate for testing: Labrador Retriever, Labradoodle, Australian Labradoodle, other Labrador crosses
Explanation of Results:
Dogs with N/N genotype will not have hereditary nasal parakeratosis and cannot transmit this hereditary nasal parakeratosis variant to their offspring.
Dogs with N/H genotype will not have hereditary nasal parakeratosis, but are carriers. They will transmit this hereditary nasal parakeratosis variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% hereditary nasal parakeratosis-affected puppies.
Dogs with H/H genotype will have hereditary nasal parakeratosis and will transmit this hereditary nasal parakeratosis variant to all of their offspring.
At least 15 business days; may be delayed beyond 15 business days if sample requires additional testing, or a new sample is requested.
Hereditary nasal parakeratosis (HNPK) is a genetic defect caused by a mutation in a gene that regulates differentiation of nose skin cells. The mutation affects specialized cells of the nose resulting in the formation of a crust with cracks over the nasal area of young dogs. Affected dogs are otherwise healthy, although leaked fluid tends to accumulate in the cracks.
HNPK is inherited in an autosomal recessive fashion with males and females being equally affected. Dogs with one normal and one affected gene (carriers) show no signs of the disease. Carrier dogs will pass on the affected gene to 50% of their offspring.
Genetic testing for the HNPK mutation is recommended for Labrador Retrievers. Labradoodles and other crosses with Labrador Retriever content may also be at risk. The test assists veterinarians with diagnosis of HNPK and helps breeders to identify carriers to avoid breeding these together. Mating of carriers is expected to produce 25% of affected puppies.
No copies of the HNPK mutation detected. Dog is normal.
1 copy of HNPK mutation detected. Dog is a carrier and unaffected. If bred to another carrier, 25% of offspring are predicted to be affected.
2 copies of HNPK mutation detected. Dog has or will develop nasal parakeratosis.
Jagannathan, V., Bannoehr, J., Plattet, P., Hauswirth, R., Drögemüller, C., Drögemüller, M., Wiener, D.J., Doherr, M.G., Owczarek-Lipska, M., Galichet, A., Welle, M.M., Tengvall, K., Bergvall, K.E., Lohi, H.T., Rüfenacht, S., Linek, M., Paradis, M.R., Müller, E.J., Roosje, P., & Leeb, T. (2013). A mutation in the SUV39H2 gene in Labrador Retrievers with hereditary nasal parakeratosis (HNPK) provides insights into the epigenetics of keratinocyte differentiation. PLoS Genetics. Oct 9(10) e1003848. doi: 10.1371/journal.pgen.1003848