Breeds Affected: Leonburger, Saint Bernard Dog
Samples Accepted: Blood, Buccal Swabs
Disease Information: LPN1 is a chronic, progressive disease that is usually diagnosed between the ages of 1 – 11 years of age; a younger age of onset is associated with more severe and rapid disease progression. Affected animals have degeneration of peripheral nerves, resulting in exercise intolerance, muscle atrophy, gait abnormalities, and laryngeal paralysis.
Inheritance Information: LPN1 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 dog is normal, and cannot produce affected offspring.
N/lpn1 The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/lpn1 carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
lpn1/lpn1 The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/lpn1 carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/lpn1 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/lpn1 x N/lpn1) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (lpn1/lpn1) should not be used for breeding.
Test Information: This mutation test identifies a 10 base pair deletion in the ARHGEF10 gene. This mutation is reported to be responsible for approximately 20 percent of LPN cases found in Leonbugers.
Ekenstedt, K.J., Becker, D., Minor, K.M., Shelton, G.D., Patterson, E.E., Bley, T., Oevermann, A., Bilzer, T., Leeb, T., Drögemüller, C., Mickelson, J.R.: An ARHGEF10 Deletion Is Highly Associated with a Juvenile-Onset Inherited Polyneuropathy in Leonberger and Saint Bernard Dogs. PLoS Genet 10:e1004635, 2014. Pubmed reference: 25275565. Doi: 10.1371/journal.pgen.1004635.
Further information is available at the Online Mendelian Inheritance in Animals website.