Hereditary ataxia / SCA / progressive degenerative myeloencephalopathy (PNPLA8-related) - Australian Shepherd

What does this test analyse?

This genetic test analyses the PNPLA8 variant c.1169_1170dup for Hereditary ataxia in Australian Shepherd dogs. The condition is also described as progressive degenerative myeloencephalopathy, spinocerebellar ataxia and SCA.

What does hereditary ataxia mean for the dog?

Hereditary ataxia is an inherited disorder in which the tested variant can cause a clear disease phenotype when a dog carries two copies. Typical signs include loss of coordination, wobbly or stiff gait, bunny-hopping, hypermetria, difficulty with stairs or rising and progressive loss of mobility.

PNPLA8 is involved in mitochondrial lipid metabolism. The c.1169_1170dup frameshift variant truncates the protein and causes the tested recessive form. The test is important for Australian Shepherd breeders because carriers can be healthy and carrier-by-carrier matings can produce affected young dogs.

Practical value of this test

• Gives breeders clear information about clear, carrier and genetically affected dogs before breeding decisions are made.
• Helps avoid carrier-by-carrier matings and thereby prevent affected puppies.
• Supports targeted selection without automatically removing healthy carriers from valuable lines.
• Makes the result useful for litter planning, purchase decisions and communication with owners or veterinarians.
• When compatible clinical signs are present, the test can provide a concrete genetic explanation for this specific condition.

Inheritance and result

The trait is inherited as autosomal recessive. A dog with two normal alleles is clear. A dog with one copy is a carrier and can pass the variant on. A dog with two copies of the variant is genetically affected for this tested form.