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Glycogen Storage Disease type II is very rare

This article was written by Pamela Francis for the FLCV in 2010. Pam's work remains an up to date and relevant summary for people who are considering buying a Finnish Lapphund. If you would like to read about steps that breeders can take to reduce the chance of hereditary disease, refer to the club breeding guidelines 2017-2020.


Pompe  disease (GSDII) has been found in the Lapponian breeds and is caused by an enzyme deficiency. The incidence of this disease has been low.  The following information is directly from the  website of Genoscoper, who perform tests for this disease:

Glycogen storage disease type II is also known as acid maltase deficiency or generalized glycogenosis type II. Glycogen storage disease type II is a disorder of glycogen metabolism that affects Finnish Lapphund, Swedish Lapphund and Lapponian herder. The disease can manifest as vomiting, muscle weakness with exercise intolerance, and poor growth. Hannes Lohi's research group at Helsinki University and Folkhälsan has identified the mutation causing Pompe's disease. The disease shows autosomal recessive inheritance.​

Glycogen storage diseases (GSD) are disorders of glycogen metabolism. GSD type II (GSD II) is a form of the disorders that affects Lapland Dogs and Lapland Reindeer Dogs. In GSD II, there is a deficit in breakdown of glycogen due to lack of the acid alpha-glucosidase enzyme. The result is cellular glycogen accumulation, and altered glucose homeostasis in tissues such as cardiac, skeletal, and smooth muscle. Signs of GSD II include poor growth, recurrent vomiting and regurgitation due a dilated esophagus (food pipe), progressive muscle weakness leading to exercise intolerance, frequent panting, and heart abnormalities. First symptoms are typically observable at 7 month of age, and affected dogs usually die or are euthanized before 2 years of age as long-term management of the disease is currently ineffective.​

The genetic test results are reported as follows:

  • Normal: The dog carries two normal copies of the gene and has no or reduced likelihood of developing the disease during its life.

  • Carrier: The dog carries the mutation in one of its chromosomes and transfers it to approximately 50% of its offspring. If a carrier must be mated, it should only be with a genetically tested healthy non-carrier.

  • Affected: The dog carries two copies of the mutation and is at high risk of developing GSD II during its life. An affected animal, even if not yet showing symptoms, will pass on the mutation to all its offspring, and its use in breeding is not recommended.


Walvoort, HC., Dormans, JA., van den Ingh, TS. Comparative pathology of the canine model of glycogen storage disease type II (Pompe's disease). J Inherit Metab Dis 8:38-46, 1985. Pubmed: 3921759.
Walvoort, HC., Slee, RG., Sluis, KJ., Koster, JF., Reuser, AJ. Biochemical genetics of the Lapland dog model of glycogen storage disease type II (acid alpha-glucosidase deficiency). Am J Med Genet 19:589-98, 1984. Pubmed: 6391168.

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