Causes of multiple sclerosis remain unknown. Contributing factors are: environment, infection, genetics and immune system.
Each could contribute to initiation of disease, relapses and progression of disease.
Over the years, almost every class of microorganism has been investigated for MS disease association, including:
Twin studies provide strong evidence for a genetic role in susceptibility to MS. These studies have shown 20-60% concordance of MS in identical twins, and 2-5% concordance in like-sex fraternal twins, traditional siblings, or children of individuals with MS.
The only genes that have been identified to have a strong association with MS are the class II major histocompatibility complex, or class II MH, genes.
Protein products of these genes are self antigens that are involved in presentation of antigen to CD4+ T cells.
The MHC gene family is highly polymorphic with more than a thousand different alleles found in humans.
Complex interactions between a persons genetic background and environment are involved in the development of MS.
Immune system plays a major role in MS.
Most people with multiple sclerosis have periods of good health, or remissions, alternating with periods of worsening symptoms, or relapses.
Initial symptoms could be:
Vague symptoms can be:
Progression of MS is unpredictable.
The clinical course varies from patient to patient, and symptoms may vary greatly within any patient over time.
Fluctuating symptoms result from damage to myelin sheaths and nerves, followed by repair or compensation, followed by more damage.
In children, the female to male ratio of cases of MS may reach three to one, whereas in people greater than 50 years of age, the female to male ratio is approximately equal.
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MHCII - Major Histocompatibility Complex II.
Multiple Sclerosis: A chronic inflammatory disease of the central nervous system characterized by multifocal lesions.