Well, I googled it and this is the web site I looked at.
http://www.nationalmssociety.org/abo...-ms/index.aspx
"While the cause (etiology) of MS is still not known, scientists believe that a combination of several factors may be involved. Studies are ongoing in the areas of immunology (the science of the body’s immune system), epidemiology (that looks at patterns of disease in the population), and genetics in an effort to answer this important question. Understanding what causes MS will be an important step toward finding more effective ways to treat it and—ultimately—cure it, or even prevent it from occurring in the first place."