Is Multiple Sclerosis Genetic?
Multiple Sclerosis is a complex disease that can be caused by several factors; genetic structure is one of them. Several genes are thought to play a role in the development of MS. If any of a close relative, such as a sibling or a parent, has this disease, your chance of developing MS is slightly higher. In fact, according to the Multiple Sclerosis Foundation, the risk of a child getting the disease is estimated to be between 2% to 5 % if one of the parents has MS.
According to the scientists, people with MS are born with a genetic vulnerability to react to certain environmental agents and when they encounter these agents, an autoimmune response is triggered.
Relationship Between Genes and the Onset of MS
There are currently 110 genes that have been known to increase the risk of developing MS. Although none of them causes the condition itself directly, someone with MS may have a combination of these genes.
As family members have some of the common genes, this does mean that it will increase the risk of developing MS if there is already one in the family. There are many cases where people diagnosed with MS do not have a family history. So, having an MS in the family doesn’t guarantee the condition, although it increases the risk.
Whilst it has been found that the rate of MS within families with a genetic history is higher, studies of identical twins reveal that genes alone are not the whole story. Identical twins have exactly the same genetic makeup as each other. So it would not be wrong to assume that if one identical twin developed the condition, so would the other. However, this isn’t the case.
An Australian study published in 2013 combined the conclusions of 18 studies to get a better assessment of the risk of MS in family members. It was found that in families, where one member was already having MS, the risk of getting the disease was highest for more closely related members.
Lifetime risk of Multiple Sclerosis by relationship to someone with Multiple Sclerosis:
- Parent - 1 in 67
- Child - 1 in 48
- Non-identical twin - 1 in 22
- Identical twin - 1 in 4
- Other brothers or sisters - 1 in 37
Relatives that were not related very closely to the MS affected person had a lower risk. Also the lifetime risk in the normal population is about 1 in 330.
The researchers concluded that genes contributed just over half (54%) of the risk factors. The rest would be due to environmental factors, probably.
Conclusion
Although MS is not believed to be a hereditary disease, the risk of getting MS is higher in close relatives of a person with the disease, especially in the case of parents, children and siblings.
However, there is only around a 2% chance of a child developing MS when a parent has already. It is important to remember that both the identical twins do not have MS always. This is why, it has been concluded that MS is not simply a genetic disease.
The further Research on MS genes will provide vital information on which biological mechanisms trigger the disease. This will lead to a better understanding of the causes of MS and lead to the development of new approaches to treatment.
