Investigation of the genetics of cerebellar abiotrophy (CA, cerebellar ataxia) in the Australian Kelpie and Australian Working Kelpie breeds.
Cerebellar abiotrophy (CA, ataxia) is a common neurodegenerative disease in dogs that spread by the extensive use of particular champion dogs in breeding. CA in Kelpies was first described by an Australian geneticist, Dr. Don Robertson in 1989, but has been recognised in the breed for more than a decade before this. The condition is defined by a loss or failure of development of cerebellar Purkinje cells and granule cells. It affects one or more Kelpie pups in a litter soon after weaning (3 to 7 weeks old) and is a progressive neurological disorder. Affected dogs are usually euthanized for humane reasons since there is no therapeutic treatment available. Clinical signs of cerebellar ataxia are head tremors, a high stepping gait, in-coordination and poor motor control.
The project is about identifying the molecular cause and mechanism that causes cerebellar abiotrophy (CA, ataxia) in Australian Kelpies. This involves searching for sequence difference/s that is (are) only present in the genome of Kelpies affected with CA. In other words, it is like looking for a needle in the haystack. Luckily, with the introduction of affordable high throughput next-generation sequencing platforms means a large amount of sequence data can be generated from multiple dogs in a matter of weeks, and these platforms may present an easier and faster way to uncover the genetic differences between affected and unaffected Kelpies.
CA is an example of autosomal recessive disorder in dogs that spread because they are not diagnosed in a timely fashion. CA in Kelpies was first reported by an Australian geneticist, Dr. Don Robertson in 1987 and was published in the Australian Veterinary Journal in 1989 . The main clinical sign is ataxia, characterised by poor body coordination, head tremors and a high stepping gait [1,2]. Ataxia may become apparent as early as five to seven weeks of age in severely affected dogs, but may not develop until twelve weeks of age in milder cases . The disease progression is slow.
The ultimate outcome of this project is to develop a reliable genetic carrier test that would allow breeders to identify CA carriers and so avoid the production of affected pups (since there is no therapeutic treatment for this disorder). In the future, once the genetic basis of CA in Kelpies is identified, it may provide a basis for investigating similar disorders in other breeds and species.