World Experts Gather In Cambridge To Bid To Unravel MS Genes, UK

"There are probably around 100 genes involved in MS and you might need, say, 70 or so of the weaker forms of these genes for it to be possible to develop the condition. Understanding the genetics of MS will not lead to gene therapy or a diagnostic test for MS.

"Instead, what an understanding of MS will allow us to do is to focus research on the relevant parts of the immune system etc. You are far more likely to come up with an effective treatment if you have a clearer understanding of the disease, rather than relying on a process of trial and error."
http://www.medicalnewstoday.com/articles/88157.php