MS Awareness Week

Patterns in the Distribution of MS

• As in other autoimmune diseases, MS is significantly more common (at least 2-3 times) in women than men. This gender difference has stimulated important research initiatives looking at the role of hormones in MS. Read more on autoimmune diseases.
• MS is not directly inherited, but genetics play an important role in who gets the disease. While the risk of developing MS in the general population is 1/750, the risk rises to 1/40 in anyone who has a close relative (parent, sibling, child) with the disease. In families in which several people have been diagnosed with MS, the risk may be even higher. Even though identical twins share the same genetic makeup, the risk for an identical twin is only 1/4—which means that some factor(s) other than genetics are involved.
• While most people are diagnosed between the ages of 20 and 50, MS can appear in young children and teens as well as much older adults. Studying the disease in different age groups may help scientists determine the cause of MS and explain why the disease course differs from one person to another. Important questions include why the disease appears so early in some children and why people who are diagnosed after age 50 tend to have a more steadily progressive course that primarily affects their ability to walk.
• In all parts of the world, MS is more common at northern latitudes that are farther from the equator and less common in areas closer to the equator. Researchers are now investigating whether increased exposure to sunlight and the vitamin D it provides may have a protective effect on those living nearer the equator.
• MS occurs in most ethnic groups, including African-Americans, Asians and Hispanics/Latinos, but is more common in Caucasians of northern European ancestry. However some ethnic groups, such as the Inuit, Aborigines and Maoris, have few if any documented cases of MS regardless of where they live. These variations that occur even within geographic areas with the same climate suggest that geography, ethnicity, and other factors interact in some complex way.

(taken from the national ms society website)