Multiple Sclerosis: Causes And Risk Factors | Musculoskeletal Issues medical answers | Body & Health Conditions center

Multiple Sclerosis is an immune disease that attacks the brain and spinal cord (central nervous system) that causes significant disability in many sufferers. There are many theories on its cause, but it is agreed that Multiple Sclerosis is an autoimmune disease (the body's immune system fights and damages itself).

It is thought that Multiple Sclerosis is caused by an interplay between the environment (trigger) in genetically predisposed individuals.

The triggers are still under investigation, but there seems to be a correlation with a number viral infections and vitamin D deficiency.

Risk factors

It is one of the most frequent causes of disability in the young. The disease has a predilection for females. It affects people around the age of 28 years of age but may be apparent by the age of 15.

Genetics

There has not been a single gene that has been identified that can be linked to Multiple Sclerosis. There appear to be a number of genes involved. It has been noted that with identical twins there is a risk of about 20-30 percent in the unaffected twin of getting multiple sclerosis, as opposed to 3-5 percent in non-identical twins; this supports that there is genetic predisposition (identical twins have identical genes as opposed to nonidentical).

Genes implicated include genes that control the immune cells and genes that handle vitamin D. Familial forms of multiple sclerosis are rare with only 3-5 percent of all multiple sclerosis sufferers have familial forms.

Environmental factors

Geographical factors

It is well known that Multiple Sclerosis has a higher incidence in certain geographical sites, such as Europe, Canada and the United States of America as opposed to the rest of the world. The geographical pattern may be explained in part by the racial differences in susceptibility, with people of African, Indian and Asian origin having the lowest risk.

It has been noted that people migrating from a high- to low-risk area after the age of puberty are thought to carry their former high risk with them. Those that migrate before puberty appear to have the risk associated with the new area to which they migrated. There have been many studies into possible factors in these has risk areas.

One proposed explanation is sunlight; it has been proposed that sunlight may be protective probably due to vitamin D.

Viral Factors

There has been some data on the association with some virus and multiple sclerosis, but it has been some difficulty linking these. A few viruses have been implicated including the Ebstein Barr virus (that causes infectious mononucleosis; glandular fever) and Varicella zoster virus (which causes chickenpox and shingles).

The strongest association thus far has been with the Ebstein Barr virus, which is thought to activate the immune system to fight against its self.

Almost 90 percent of all adults have been infected with this virus, but its has been noted that almost 100 percent of all Multiple Sclerosis sufferers have been infected in some studies.

Other Factors

There have been other studies to try and identify other factors, such as the month of birth and smoking, but the results are conflicting. There was also some debate about vaccinations, but this has been clearly refuted with evidence by the medical community.