Lagotto Storage Disorder

Common Symptoms

Lagotto storage disorder is an inherited metabolic disorder affecting lagotto Romagnolos. Dogs with this disease produce inadequate amounts of an Enzyme which plays an important role in degradation, storage, and removal of cellular material from cells. As a result, this material accumulates in a variety of body’s cells, including those of the nervous system. The accumulation of this material results in an adult-onset progressive neurological disease most commonly presenting between 1 and 5 years of life. Clinical signs of neurological dysfunction in affected dogs include abnormal gait, weak or absent reflexes, limb weakness, behavioral changes, abnormal movement of the eyes (Nystagmus), aggression, restlessness, and depression. The speed of disease progression varies, but most affected dogs are euthanized months to years after initial clinical signs due to quality of life concerns.

Breed-Specific Information for the Lagotto Romagnolo

The Mutation of the gene associated with lagotto storage disease has been identified in lagotto Romagnolos. Though the exact frequency in the overall lagotto Romagnolo population is unknown, approximately 11% out of 2352 lagotto Romagnolos tested were carriers of the mutation.

Testing Tips

Genetic testing of the ATG4D gene in lagotto Romagnolos will reliably determine whether a dog is a genetic Carrier of lagotto storage disorder. Lagotto storage disorder is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the ATG4D gene mutation. Reliable genetic testing is important for determining breeding practices. Because symptoms may not appear until adulthood, genetic testing should be performed before breeding. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Lagotto Romagnolos that are not carriers of the mutation have no increased risk of having affected pups.

There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.

References

• Kyöstilä K, Syrjä P, Jagannathan V, Chandrasekar G, Jokinen TS, Seppälä EH, Becker D, Drögemüller M, Dietschi E, Drögemüller C, Lang J, Steffen F, Rohdin C, Jäderlund KH, Lappalainen AK, Hahn K, Wohlsein P, Baumgärtner W, Henke D, Oevermann A, Kere J, Lohi H, Leeb T. A missense change in the ATG4D gene links aberrant autophagy to a neurodegenerative vacuolar storage disease. PLoS Genet. 2015 Apr 15;11(4):e1005169. doi: 10.1371/journal.pgen.1005169. [PubMed: 25875846]
• Syrjä P, Anwar T, Jokinen T, Kyöstilä K, Jäderlund KH, Cozzi F, Rohdin C Hahn K, Wohlsein P, Baumgärtner W, Henke D, Oevermann A, Sukura A, Leeb T, Lohi H, Eskelinen EL. Basal Autophagy Is Altered in Lagotto Romagnolo Dogs with an ATG4D Mutation. Vet Pathol. 2017 Nov;54(6):953-963. doi: 10.1177/0300985817712793. [PubMed: 28583040]