Breeds Affected: Newfoundland Dog, Landseer
Samples Accepted: Blood, Buccal Swabs
Disease Information: Thrombopathia in the dog may result in prolonged bleeding times. Small petechia (microhemorrhages) under the skin and in mucus membranes also leads to occasional bleeding from the gums or nose.
Inheritance Information: Thrombopathia 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/t The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/t carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
t/t The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/t carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/t 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/t x N/t) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (t/t) should not be used for breeding.
Test Information: This mutation test identifies a single base change in exon 8 of RASGRP1.
Boudreaux, MK., Catalfamo, JL., Klok, M.: Calcium-diacylglycerol guanine nucleotide exchange factor I gene mutations associated with loss of function in canine platelets. Transl Res 150:81-92, 2007. Pubmed reference: 17656327. Doi: 10.1016/j.trsl.2007.03.006.
Further information is available at the Online Mendelian Inheritance in Animals website.