Is Cerebellar Degenerative Disorder Hereditary In Nature?

Hello. Just recently, my mother was diagnosed with a cerebellar degenerative disorder. Her mother (deceased at 59) and her grandfather (death date unknown) have also succumb to variations of this disease. Her neurologist stated that this disorder may be hereditary in nature and that my sister and I should get some sort of testing to see if we would be affected. What is this type of testing, and where may I go to receive it? Also, if possible, is there an estimate of how much this type of testing would cost and will insurance companies pay for it? Thank you in advance for your reply.