Cerebellar Ataxia (CA) in the Italian Spinone
Cerebellar ataxia (CA) in the Italian Spinone is a serious neurological disease. In affected dogs, the cerebellum, which is part of the brain responsible for the coordination of motor movement in the body, becomes diseased. Affected dogs are born normal, but clinical signs, including the development of an unsteadt gait, loss of coordination and poor balance, usually appear in the first weeks or months of life. The disease is progressive; symptoms worsen during the first year of the dog's life such that most dogs are euthanized before they are a year old. There is no treatment for the disease.
The disorder shows an autosomal recessive mode of inheritance: A dog has to inherit two copies of the defective gene (one from each parent) for it to be affected by the disease. Dogs with one copy of the defective gene and one copy of the normal gene are called carriers and show no clinical signs but can pass the defective gene on to their offspring. When two apparently healthy carriers are crossed, 25% (on average) of the offspring will be affected by the disease, 25% will be clear and the remaining 50% will be carriers.
The region of the genome that contains the causal mutation has recently been identified at the Animal Health Trust. Using the information gained from this research, they have developed a linkage-based DNA test for the disease, which they estimate will give an accurate result for between 95% and 98% of dogs tested. This test will detect those dogs that are carriers of the CA mutation and those that are clear of the mutation.
Breeders will be sent results identifying their dog as belonging to one of three categories:
CLEAR: The dog has two copies of the normal gene and will neither develop cerebellar ataxia nor pass a cerebellar ataxia gene to their offspring.
CARRIER: The dog has one copy of the normal gene and one copy of the mutant gene that causes cerebellar ataxia. The dog will not develop cerebellar ataxia, but will, if bred, pass the cerebellar ataxia gene to, on average, 50% of its offspring.
AFFECTED: The dog has two copies of the mutant gene that causes cerebellar ataxia and will develop the disease. Carriers can still be bred to dogs that test clear. On average, 50% of such a litter will be clear and 50% carriers; there will be no affected pups produceds from such a mating. Pups to be used for breeding can themselves be DNA tested to determine whether they are clear or are a carrier.
Samples submitted is an important step in maintaining the health of dogs and their offspring. The Canine Health Information Center (CHIC), is a centralized canine health databased jointly sponsored by the AKC Canine Health Foundation and the Orthopedic Foundation for Animals (OFA). CHIC, working with participating parent clubs, provides a resource for breeders and owners of purebred dogs to research and maintain information on the health issues prevalent in specific breeds. For more information about CHIC eligibility, obtaining a CHIC number, fees and how to enroll a breed in the CHIC program, visit us as www.akcchf.org/about-us/alliances.
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