Genes and MS

There’s no single gene that causes MS. Scientists have so far found over 200 genes which might affect the risk of MS, and 1 gene which affects how the MS progresses over time.

Research into genetics could help treat and even prevent MS.

What are genes?

Genes are instructions for our bodies. They’re a code that’s passed on from our parents. They influence things like our height and hair colour. They can also affect our chances of developing certain health conditions, including MS.

Is MS in my genes?

Genes do play a role in MS, but they’re only part of the story. There’s no single gene that causes someone to get MS. But we know that having certain versions of particular genes can make a person more likely to get MS. Genes are involved in MS in complicated ways, but they’re not the only thing that affects someone’s risk of getting MS or how their MS might develop.

Identical twins

Identical twins have extremely similar genes, but if one gets MS, the other usually doesn’t. For people who have an identical twin with MS, about 1 in 5 will get MS (about 4 in 5 won’t).

If genes were the only thing affecting who got MS, identical twins would almost always either both get MS or neither would. Our environment and lifestyle also play a part.

MS in the family - what are the chances?

MS isn’t passed directly from parents to their children – because it isn’t caused by a single gene. While MS can occur more than once in a family, it’s more likely that this won’t happen. We can work out the chances of relatives developing MS by looking at the history of MS in families around the world.

Genes and MS progression

Genes also affect how MS behaves - how quickly it progresses or whether someone has relapses. Recent research found the first gene linked to MS progression. It showed that the genes affecting progression are different from those influencing who gets MS.

But other factors including age and smoking also influence how MS progresses. It’s not just the genes. We need more research to understand the role of genes in MS progression. In future, genetic research could mean better treatments and lifestyle recommendations for each person.

Genes, environmental and lifestyle factors

Most people who’ve got genes linked to MS won't get the condition. Other things also play a part: often called environmental and lifestyle factors. These are things like infections, levels of vitamin D, and smoking. They’ve all been shown to play a role in developing MS and could affect how someone’s MS changes over time. Also, the genes we know about are probably the tip of the iceberg. Future, larger research studies will probably discover new MS risk genes.

Triggers

Some people might be more likely to get MS than others due to their genes. But that does not mean that they will actually get MS.

We don't understand why some people get MS even though they don't have many risk genes. Or why some people with lots of risk genes never get MS. We think there may be other factors – ‘triggers’ – which kickstart MS.

These triggers might be a combination of different environmental and lifestyle factors. It might vary from person to person. This is a big area of research, because if we find the triggers we can perhaps stop MS before it starts.

Read more about the causes of MS

Does my ancestry affect my risk of MS?

We don’t know how much ancestry might affect your own risk of MS. Most studies into genes and MS have involved people of White European descent. So there might be differences for people from other ancestries that we don’t know about.

The ADAMS study has shown that the most important MS risk genes have similar impact for people of South Asian and African ancestry. We need larger, more diverse genetics studies so we can understand the link between ancestry, genes, and MS risk.

Find out more about the ADAMS study and how you could take part

Is there gene therapy for MS?

Gene therapy aims to treat or prevent a condition by adjusting genes - instead of using drugs or surgery. Because MS is not caused by a single gene it’s not likely that gene therapy will be an effective way of preventing MS.

Is there a genetic test for MS?

There’s not a genetic test that can give a simple, clear answer to: ‘Will I get MS?’ Even a test that could show all the genes involved wouldn’t be enough on its own to answer this. Having genes linked to MS doesn’t mean you will get MS. Genes aren’t the only risk factor for MS, so a genetic test alone can’t clearly say someone will get MS.

How can genetic research help people with MS?

Research into genes and MS can help us:

• understand why certain people are more likely to get MS
• discover ways to reduce the risk of getting MS
• explain why some people with MS respond to treatments, while others don’t
• develop new treatments targeting particular genes

This kind of approach has been successful for diabetes, another condition where lots of genes are involved.

What has genetic research told us about MS?

MS genetic research has already discovered

• Over 200 genes are linked to MS – lots of them play a role in the immune system, and some are linked to other autoimmune conditions
• Some genes are linked to both MS and vitamin D – in a study, people with four particular genes had lower levels of vitamin D and were more likely to get MS
• Another gene linked to MS becomes more active when vitamin D levels increase
• Genes that raise the risk of being overweight have also been linked to MS – this genetic research backs up other studies that noticed a link between obesity and the risk of MS

Genetic research we’re funding and supporting 

We’re funding projects to understand the role genes play in MS:

• identifying who will benefit most from beta-interferons
• discovering why some MS progresses and some doesn’t
• developing techniques to repair people’s damaged myelin
• understanding the link between genes and MS in people from diverse ancestral backgrounds

Find out more about genetic research and MS