Breeds Affected: Many breeds, including but not limited to: Burma, Rex (Cornish, Devon), Tonkinese, Singapura, and Sphynx
Samples Accepted: Blood, Buccal Swabs
Disease Information: Hyperkalemic Periodic Paralysis, also known as Burmese Periodic Polymyopathy (BHP) is normally first noticed in affected kittens between 2-6 months of age. Muscle weakness is common, and episodes may be triggered by exercise or stress, leading to muscle pain, tremors, head-bobbing, and a short, crouching gait. Some affected cats require life-long potassium supplementation.
Inheritance Information: BHP is autosomal recessive, meaning that animals with two copies of this allele will be affected. Animals with one copy of the gene will be clinically-normal carriers.
The possible genotypes are:
N/N The cat is normal, and cannot produce affected offspring.
N/bhp The cat is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/bhp carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
bhp/bhp The cat is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/bhp carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/bhp x N/N) without any risk of producing affected offspring. The offspring should be tested before breeding to determine if they are carriers or normal.
– Breeding two carriers (N/bhp x N/bhp) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (bhp/bhp) should not be used for breeding.
Test Information: This mutation test identifies a single base change in intron 50 of the WNK4 gene.
Gandolfi, B., Gruffydd-Jones, T.J., Malik, R., Cortes, A., Jones, B.R., Helps, C.R., Prinzenberg, E.M., Erhardt, G., Lyons, L.A.: First WNK4-Hypokalemia Animal Model Identified by Genome-Wide Association in Burmese Cats. PLoS One 7(12):e53173, 2012. Pubmed reference: 23285264. Doi: 10.1371/journal.pone.0053173.
Further information is available at the Online Mendelian Inheritance in Animals website.