Breeds Affected: Domestic Short Hair
Samples Accepted: Blood, Buccal Swabs
Disease Information: GM2a Gangliosidosis, a lysosomal storage disorder, is a slowly progressing neuromuscular disease. Affected kittens may seem “clumsy”, but by 14 months of age, a lack of motor coordination and abnormal startle response and tremors are apparent.
Inheritance Information: GM2a 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/gm2a The cat is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/gm2a carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
gm2a/gm2a The cat is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to an N/gm2a carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/gm2a 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/gm2a x N/gm2a) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (gm2a/gm2a) should not be used for breeding.
Test Information: This mutation test identifies a 4 base deletion in the GM2 gene.
Martin, DR., Cox, NR., Morrison, NE., Kennamer, DM., Peck, SL., Dodson, AN., Gentry, AS., Griffin, B., Rolsma, MD., Baker, HJ.: Mutation of the GM2 activator protein in a feline model of GM2 gangliosidosis. Acta Neuropathol (Berl) 110:443-50, 2005. Pubmed reference: 16200419. Doi: 10.1007/s00401-005-1040-6.
Further information is available at the Online Mendelian Inheritance in Animals website.