is not considered a hereditary disease. The risk of getting MS is
higher in relatives of a person with the disease than in the general
population, especially in the case of siblings, parents and children.
However, there is only around a 2% chance of a child developing MS when a
parent is affected. It is important to consider that identical twins,
who have the same genetic material, do not always both have MS. There is
around a 20-30% chance of a twin of developing MS if their identical
twin is affected. This is why researchers agree that MS is not simply a
a number of genetic variations have been shown to increase the risk of
developing the disease. Research into the genetics of MS involves the
search for genes that contribute to susceptibility and/or to the
severity and other aspects of the disease, including the response to
treatments. Apart from familial studies, specific genes have been linked
with MS. The majority of them involve genes that influence specific
cells of the immune system. These are also the genes that seem to
contribute more significantly than others to the susceptibility of the
disease. Differences in the human leukocyte antigen (HLA) system, a
group of genes that serves as the major histocompatibility complex (MHC)
in humans, also influence the probability of getting MS.
search for MS genes is important because their discovery will provide
vital information on which biological mechanisms influence the disease.
This will lead to a better understanding of what causes MS and to the
development of new approaches to treatment and prevention.