SPINOCEREBELLAR ATAXIA (SCA)
Affected dogs show progressive signs of cerebellar ataxia (loss of muscle coordination) as early as 2-6 months of age. The majority of cases also develop myokymia (involuntary twitching of the muscles) which also becomes progressively worse with age. A small percentage of dogs with SCA have true epileptic seizures, some as young as 10 weeks of age. Most dogs with SCA are euthanized young due to poor quality of life.
Interpreting DNA test results for SCA
Clear dogs have no copies of the mutant gene responsible for the condition and will neither develop the condition nor pass the gene on to their offspring.
Carrier dogs have one copy of the normal gene and one copy of the mutant gene; they will not develop the condition, but will pass a mutant gene on to approximately half of their offspring.
Affected dogs have two copies of the mutant gene that causes the condition and will develop the disease.