The cause of multiple sclerosis (MS) is unknown. Scientists have proven that MS is autoimmune in origin. In other words, the damage in MS is caused by the body’s immune system attacking its own tissues, but scientists have not yet figured out why this process begins. Autoimmune attacks in MS are directed at the tissues of the central nervous system, specifically the myelin sheath that surrounds nerve fibers of the spinal cord, brain, and optic nerve. MS damages the myelin sheath and sometimes the nerve cells as well, leading to MS symptoms like vision problems, spasticity, and muscle weakness. Autoimmune attacks in MS are directed at the tissues of the central nervous system, specifically the myelin sheath that surrounds nerve fibers of the spinal cord, brain, and optic nerve. MS damages the myelin sheath and sometimes the nerve cells as well, leading to MS symptoms like vision problems, spasticity, and muscle weakness.
Although researchers have established that both hereditary and environmental factors influence a person’s risk of developing MS, no one has identified why some people are diagnosed with MS and some aren’t. Most scientists believe MS is most likely caused by a combination of inherited and environmental factors.
Risk Factors for MS
Science is good at finding correlations — or apparent relationships — between factors and disease, but correlation does not prove that the factor causes the disease. Many risk factors for MS have been identified and are being studied, but none has been pinpointed as the cause of MS.
Genetic Factors
MS does not appear to be directly inherited from parents in any clear genetic pattern. However, people with a parent or sibling who has MS have a higher risk of developing the disease. The average person’s risk of developing MS is 0.2 percent.
If someone has a sibling with MS, their risk of developing MS is between 2 percent and 4 percent. In identical twins, if one twin is diagnosed with MS, the other twin has up to a 30 percent chance of developing the condition. Research to better understand genetic susceptibility for MS is ongoing.
Gender
Women are about three times as likely as men to develop MS. In general, there is a greater prevalence of autoimmune disease in females than males. In the United States, 75 percent of those with an autoimmune disease are women.
Women’s immune systems are believed to be more effective than men’s, giving women greater protection from infections, but making them more vulnerable to autoimmune disorders.
Race and Ethnicity
Ethnicity may influence MS predisposition. A research study from Multiple Sclerosis found that MS “has a strong racial and ethnic component and disproportionately affects whites of European background.” It also found that rates are increasing among African Americans, Hispanics, and Asians.
These groups may also experience symptoms differently and vary in the typical age at diagnosis relative to whites. Some ethnic groups, such as the New Zealand Maori and other indigenous peoples, have a low incidence of MS.
“To read this article in its entirety click this link: Causes of Multiple Sclerosis.”