Cerebellar cortical degeneration Hungarian Vizsla Type
Cerebellar cortical degeneration Hungarian Vizsla Type is a hereditary disorder of the central nervous system affecting the Hungarian Vizsla breed. Degenerative cerebellar diseases are collectivly known as abiotrophies and are characterized by neuronal degeneration and neuronal loss. Cerebellar aviotrophies have been diagnosed in several dog breeds, such as Beagles, Rhodesian Ridgebacks, Old English Sheepdogs, Gordon Setters and Scottish Terriers. The disorder differs amonf these breed by the angle of symptoms’ onset as well as the causative mutation. Cerebellar cortical degeneration Hungarian Vizsla Type appears to be a juvenile form of the disease.
Characteristics and Symptoms
Histopathological examination of CCD affected dogs reveals a loss of Purkinje neurons in the cerebellar cortex. In some breeds, the neurodegenerative lesions can be observed also outside the cerebellum, such as the spinal cord the cerebral cortex and the brain stem. The first visible symptoms may include stumbling, truncal sway and ataxia exacerbated by lifting the head up and negotiating stairs. With the disorder progression, obvious ataxia devlopes, characterized by dysmetria, nystagmus, coarse intention tremor, variable loss of menace reacton and truncal sway. In the final stages of the disease, dogs become unable to walk without falling repeatedly.
Cerebellar cortical degeneration Hungarian Vizsla Type Genetics
Cerebellar cortical degeneration Hungarian Vizsla Type is caused by a mutation in SNX14 gene. The disorder is inherited in an autosomal recessive pattern. Healthy parents of an affected dog are obligate heterozygotes, and therefore carry one mutant allele. Heterozygotes are carriers and show no symptoms. At conception, each cub has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.
Fenn, J. et al (2016) Genome sequencing reveals a splice donor site mutation in the SNX14 gene associated with a novel cerebellar cortical degeneration in the Hungarian Vizsla dog breed. BMC Genetics 17:123.