Test Detail

Glycogenosis of the Curly-Coated Retriever due to deficiency of the glycogen debranching enzyme (AGL), which prevents complete degradation of glycogen and causes its abnormal accumulation in liver and muscle. It produces hepatomegaly, elevated liver and muscle enzymes, exercise intolerance and, over time, liver fibrosis and myopathy. It is inherited in an autosomal recessive manner. In this breed the course is relatively mild compared with other canine forms.

Affected breed: Curly-Coated Retriever. Carriers have been identified in the USA, New Zealand, Australia and Finland, but no reliable global population frequencies are published; the disease is rare and known within the breed.

- Test Curly-Coated Retriever breeding animals with the AGL test (c.4223delA)
- Do not mate two carriers: 25 % risk of affected homozygotes
- A carrier can be mated to a clear animal; offspring intended for breeding must be tested
- Exclude affected animals from breeding and test parents and siblings of cases
- In carriers with good qualities, always mate to clear animals and test the offspring

Differential diagnosis with other glycogenoses (GSD Ia, GSD II/Pompe), hereditary myopathies and congenital liver diseases. Measurement of debranching activity in liver/muscle and the genetic test are confirmatory. Dietary management (high-protein diet, cornstarch) may improve exercise tolerance and liver function, without halting progression. Biochemical (ALT, AST, ALP, CK) and ultrasound follow-up recommended.

1. Gregory BL, Shelton GD, Bali DS, et al. Glycogen storage disease type IIIa in curly-coated retrievers. J Vet Intern Med 2007;21(1):40-6. PMID: 17338148
2. Yi H, Thurberg BL, Curtis S, et al. Characterization of a canine model of glycogen storage disease type IIIa. Dis Model Mech 2012;5(6):804-11. PMID: 22736456
3. OMIA:001577-9615 (AGL). https://omia.org/OMIA001577/9615/