- Type Disease
Nervous System
- Name
Lysosomal Storage Diseases
- Abbreviation
LSDx
- Description
The lysosomal storage diseases include ceroid lipofuscinosis, fucosidosis, glucocerebrosidosis, glycogen storage disease type III, GM1 gangliosidosis, GM2 gangliosidosis, mucopolysaccharidosis I, sphingomyelinases. In these disorders, there is a deficiency of a particular enzyme necessary for normal metabolic processes within the body. The result is an accumulation in cells (storage) of whatever product the enzyme normally acts upon. Cells become swollen and incapable of normal function. Although these conditions can affect many different body systems, most often the clinical signs relate to abnormalities in the nervous system. Typically, animals with a storage disease are normal at birth, fail to grow as rapidly as littermates, and at a consistent age, develop progressive signs of a nervous disorder which will ultimately prove fatal.\n\nThese disorders are generally rare. Because of similar diseases in people however, these conditions are better studied than many other, more common, inherited disorders in dogs.
- How Transferred
Where inheritance has been determined, it is autosomal recessive.
- What to Look for
These disorders, fortunately rare, are devastating. Pups are normal at birth and then gradually (most commonly before 1 year of age) develop signs of neurologic disease. Their demeanor, behavior and motor abilities are affected to varying degrees depending on the disorder, but the condition always worsens until the dog dies or is euthanized, usually within 6 months of the first signs.
- Diagnosis
These conditions are difficult to diagnose, both because they are very uncommon and because the clinical signs are often vague (eg.depression, behavior change). Generally the routine diagnostic tests your veterinarian will carry out will show no abnormalities.\n \nOnce a lysosomal storage disease is suspected, your veterinarian will submit a blood sample for specific diagnostic tests which are now available for many of these disorders. These tests measure blood levels of the particular enzyme involved, and many can detect carriers of the disorder (who have about 50 per cent normal enzyme levels) as well as affected dogs. For those disorders in which the specific genetic defect has been identified, it is likely that before long there will be a DNA test that can be used to differentiate normal, carrier, and affected dogs.
- Treatment
Unfortunately there is no treatment available for these disorders, which can only be controlled by good breeding programs.\n \nAs gene therapies emerge, they will likely first be developed for these conditions, many of which are controlled by a single gene and involve a single defective enzyme.
- Veterinarian Information
Generally there is a combination of cerebral and cerebellar signs.
- Breeding Considerations
Affected animals and their parents (carriers of the defective gene) should not be bred. Siblings are suspect carriers and should only be used for breeding if a screening test has been carried out, showing that they are not carriers. In this way, these devastating diseases can be greatly reduced or eliminated from the breeds in which they occur.\n
- Known Breeds Affected
American bulldog\nEnglish springer spaniel\nPortuguese water dog\nSaluki\nSchnauzer, miniature
