I absolutely think that Huntington's disease should be a disability claim. It's rough seeing these people have to suffer due to a disease that quite frankly isn't their own fault. From what I've seen, these people don't actually live to be the average age so the least we could do is help them out while we can.
Any person suffering from Huntington's disease should be allowed to go on disability once the symptoms start to pose any sort of issue to daily functioning and tasks. I can not imagine how it feels so know your brain is slowly losing function and failing your body. That burden is heavy enough to carry without having to worry about how someone with it will support themself.
Yes, people should be able to get on disability because of Huntington's disease. This disease slowly damages the nerves in a persons brain, so they will be affected by this disease greatly. After the damage goes far enough, people will be unable to work and function normally, and will need disability pay.
I believe that people should not go on disability due to Huntington's disease symptoms. When they begin experiencing symptoms, they should go the doctor to be tested for the disease and begin looking into disability so they will be prepared should they be diagnosed with the actual disease. You cannot go on disability without a confirmed diagnosis from a doctor.
I do not believe all people diagnosed with Huntington's Disease automatically qualify for Social Security Disability. The disease is not always debilitating ways right at the start. The disease can progress differently for each individual patient. I think it is best to take each case individually rather than say all people should be granted disability.