The cause of multiple sclerosis is still unknown. In the last 20 years, researchers have focused on disorders of the immune system and genetics for explanations. The immune system is the body's defender and is highly organized and regulated. If triggered by an aggressor or foreign object, the immune system mounts a defensive action which identifies and attacks the invader and then withdraws. This process depends upon rapid communication among the immune cells and the production of cells that can destroy the intruder. In multiple sclerosis, researchers suspect that a foreign agent such as a virus alters the immune system so that the immune system perceives myelin as an intruder and attacks it. The attack by the immune system on the tissues that it is supposed to protect is called autoimmunity, and multiple sclerosis is believed to be a disease of autoimmunity. While some of the myelin may be repaired after the assault, some of the myelin disappears and nerves are stripped of this covering (become demyelinated). Scarring also occurs, and material is deposited into the scars and forms plaques.
Although its role is unclear, genetics may play a role in multiple sclerosis. European gypsies, Eskimos and African Bantu essentially do not develop multiple sclerosis, while Native Indians of North and South America, Japanese and other Asian groups have a low incidence. The general population has less than a one-percent chance of ever contracting multiple sclerosis. The chance increases in families where a first-degree relative has the disease. Thus, a brother, sister, parent, or child of a person with multiple sclerosis stands a one-percent to three percent chance of developing multiple sclerosis. Similarly, an identical twin runs a nearly 30% chance of acquiring multiple sclerosis whereas a non-identical twin has only a 4% chance if the other twin has the disease. These statistics suggest that genetic factors play a major role in multiple sclerosis. However, other data suggest that environmental factors also play an important role.
The symptoms of multiple sclerosis can vary greatly from patient to patient. What were your symptoms at the onset of your disease?
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