Glycogen storage disease, type II

Gene: GAA

Transmission: Autosomal recessive

For an autosomal recessive genetic disease, an animal must have two copies of the mutation in question to be at risk of developing the disease.  Both parents of an affected animal must be carriers of at least one copy of the mutation.  Animals that have only one copy of the mutation are not at risk of developing the disease but are carrier animals that can pass the mutation on to future generations.

Mutation: Substitution, GAA gene; c.1799 G>A, p.(R600H), exon13, chr.E1.

Medical system: Muscular, metabolic

Breeds: Domestic Cat, Japanese Domestic

Age of onset of symptoms: Early during growth phase.

An 8-month-old domestic shorthaired cat was presented to a veterinary clinic in Japan with rapid breathing, poor growth, poor appetite, and muscle weakness.  Radiographs revealed a hypertrophic cardiomyopathy.  The animal died at about 1 year of age due to pulmonary edema.  Pathological studies revealed an accumulation of glycogen within cardiac muscle, and a post-mortem diagnosis of glycogen storage disease type II (Pompe disease) was made.  Genomic studies revealed a homozygote mutation in the GAA gene, which codes for the protein a-glucosidase, a lysosomal enzyme responsible for breaking down glycogen into glucose molecules.  The clinical, pathological, and molecular findings in the case are similar to the presentation of Pompe disease in humans.  The frequency of Pompe disease in the domestic cat population in Japan is not known, presumably due to the difficulty of making a specific diagnosis considering the general nature of presenting signs.  The frequency of the mutation in the GAA gene in the domestic cat population has not been determined, although a DNA test can now be performed.

References:

OMIA link: [0419-9685]

Rakib TM, Islam MS, Tanaka S, et al. (2023) Novel Mutation in the Feline GAA Gene in a Cat with Glycogen Storage Disease Type II (Pompe Disease). Animals (Basel) 13(8):1336.  [pm/37106898]

Tanaka S, Suzuki R, Koyama H, et al. (2022) Glycogen storage disease in a young cat with heart failure. J Vet Intern Med 36(1):259-263.  [pm/34939226]

Contributed by: Mathieu Guy-Samson et May Lapierre-Olivier, Class of 2028, Faculty of Veterinary Medicine, University of Montreal. (Translation DWS).