Fucosidosis is an inherited lysosomal storage disease affecting dogs. Affected dogs have a deficiency of the Enzyme alpha-L-fucosidase which is responsible for breaking down complex sugars during normal cellular metabolism. As a result, there is an accumulation of these compounds primarily in cells of the nervous system affecting the normal function of the brain and nervous system. Affected dogs typically present with symptoms between 11 months and 4 years of age. Symptoms include loss of balance, deafness, change in temperament, loss of learned skills, blindness, difficulty eating, and weight loss. Once an affected dog begins to show signs of the disease, dogs are usually euthanized within 18 months.
Genetic testing of the FUCA1 gene in will reliably determine whether a dog is a genetic Carrier of fucosidosis. Fucosidosis 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 any 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 FUCA1 gene mutation. Reliable genetic testing is important for determining breeding practices. 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. Dogs 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.
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