the autosomal dominant part of the Dx means that it takes one and only one parent to pass along the problem, that 50% of children will inherit it. As far as MS goes, it is not that strongly geneticaly linked; at most there probably is a predisposition towards getting the disease from a parent.

And I would be cautious about too strong of a correlation between MRI spots, no matter where they occur, and symptoms, there is not that sort of linkage yet. And spots on an MRI do not necessarily mean MS, there is a large group of diseases called leukodystrophies, for instance, that cause myelin problems. They are fatal genetic diseases, and they cause all of the symptoms you describe.

In addition to an MRI, a positive lumbar puncture is needed to Dx MS. It sound like the genetic testing is a hunt for something else, something worse than MS.