Is Multiple Sclerosis Genetic?

Disclaimer: This article is for informational purposes only and is not intended for diagnostic use. LifeDNA does not provide diagnostic reports on any traits discussed. Genetics is just one piece of the puzzle; please consult a healthcare professional for comprehensive guidance on any health condition.

Overview

Imagine waking up and your arm feels numb, or your vision suddenly blurs for no reason. Other days, your body just doesn’t respond the way it should. These are some of the invisible and confusing signs of Multiple Sclerosis or MS. But where does it come from?

Researchers are still working to understand the full picture. What we do know is that MS involves a mix of genetics, environmental triggers, and how the immune system behaves. Learning more about MS, especially its possible causes and early signs, may help people make informed choices about their health and lifestyle.

What Is Multiple Sclerosis?

Multiple Sclerosis, or MS, is a long-term condition that affects the central nervous system. It affects mainly the brain and spinal cord. MS can show up in a lot of different ways, some people feel extreme tiredness, others may have numbness, muscle weakness, or problems with balance and coordination. In MS the body’s own immune system, which is supposed to defend you from outside invaders, mistakenly attacks your healthy cells. In this case, it targets the protective covering of nerve fibers, called myelin. When myelin gets damaged, its signaling slows down or is bloced between the brain and the rest of the body.

What Are The Types of Multiple Sclerosis?

MS can show up in different ways. Here are five types Doctors use to describe how it behaves:

Clinically Isolated Syndrome (CIS)
This is a first episode of symptoms caused by inflammation in the brain or spinal cord. It may affect vision, movement, or sensation. The symptoms usually go away fully or almost fully. Even if this is the only episode, tests like an MRI or spinal tap may show hidden damage. If the damage is found, doctors may confirm a diagnosis of MS.
Relapsing-Remitting MS (RRMS)
This is the most common form of MS. People with RRMS have attacks of symptoms called relapses followed by times of recovery called remissions. These quiet periods may last for weeks, months, or even years. Special treatments may help reduce how often the attacks happen or may stop them completely. Most people are first diagnosed with this type.
Secondary-Progressive MS (SPMS)
This type usually develops after relapsing-remitting MS. Over time, relapses become less common or may stop, but symptoms slowly get worse. If attacks still happen, it is called “active” SPMS. If there are no more attacks, it is called “non-relapsing.” Treatment during the early stage may slow or delay this phase, but it may still occur.
Primary-Progressive MS (PPMS)
This form of MS gets worse from the start. There are no clear attacks or recovery periods. Symptoms slowly build over time. Some days may feel better or worse, but the general trend is steady decline.
Radiologically Isolated Syndrome (RIS)
This is the rarest form of MS. A person has no symptoms, but an MRI scan shows signs of MS-like damage. Even though the person feels fine, symptoms may develop later on.

What Causes Multiple Sclerosis?

While there’s no single cause, scientists believe Multiple Sclerosis or MS happens when several factors come together. One could be when the immune system mistakenly attacks the body’s own central nervous system. In this condition, the immune system targets myelin, which is a mixture of protein and fatty acids that form a protective coating, known as the myelin sheath, around nerve fibers or axons.

Myelin not only insulates the nerves but also plays an important role in helping signals travel quickly and clearly between neurons. This is also what gives the brain’s white matter its pale appearance. The immune attack in MS is focused on the central nervous system, which includes the brain, spinal cord, and optic nerves that connect the eyes to the brain.

The damage in MS goes beyond just the myelin sheath. Over time, it also affects the axons themselves and the nerve cell bodies located in the brain’s gray matter. As the disease progresses, the brain’s outermost layer, known as the cerebral cortex, begins to shrink, a process called cortical atrophy. The way cortical atrophy occurs in MS may share similarities with what is seen in some neurodegenerative conditions.

The term sclerosis refers to the areas of hardened, scar-like tissue also called plaques or lesions that develop where the immune system has attacked. These plaques can be tiny, about the size of a pinhead, or large, like a golf ball. They can be seen on magnetic resonance imaging or (MRI) scans. Symptoms of MS depend on the size, number, and location of these plaques in the nervous system, leading to different effects in each individual.

MS most often begins in early adulthood, usually between the ages of 20 and 40. This pattern has prompted scientists to suggest that environmental triggers and genetics are involved.

Genetics on Multiple Sclerosis

Studies have shown that MS risk is strongly linked to the immune system, and especially a gene called HLA-DRB1. This gene helps control how the immune system responds to threats, and certain genetic variants in it increase the chance of developing MS.

With better research tools like Genome-Wide Association Studies (GWAS), scientists have found over 200 genetic variants linked to MS. Most of these have small effects on their own, but together they help explain why some people are more at risk.

Most of these genetic changes aren’t in the parts of DNA that code for proteins. Instead, they’re in regions that control when and how genes are turned on or off. For example, some changes affect genes like IL2RA, IL7R, and TNFRSF1A, which are important for how the immune system works. These small changes might increase the chance of the immune system attacking the body by mistake, which happens in MS. That’s one reason why these diseases can sometimes run in the same families.

Another study shows that identical twins who have the exactly same genes have a much higher chance of both getting the MS, which is about 25% to 30%, compared to fraternal twins, who share only some of their genes and have a risk of about 3% to 7%. This means that genes do play a role in MS, but they are not the only reason someone gets the disease.

Research has also looked at large groups of people to estimate how much of MS is linked to genetics. One study from Sweden says that about 64% of the risk comes from genetics, while the rest is due to things in the environment or lifestyle. Another study from Italy found a similar result, with genetics making up about half of the risk.

How Do Environmental Factors Come Into Play?

Having a genetic risk doesn’t mean MS is inevitable. A person’s environment and lifestyle can influence whether or not the condition actually develops. Some of the more studied triggers include:

Sunlight & Vitamin D: People who live in places with less sunlight often have higher rates of MS. That’s probably because sunlight helps your body produce vitamin D, which supports healthy immune function.
Viral Infections: One of the strongest connections is with the Epstein-Barr virus (EBV). This virus causes mononucleosis, and people who’ve had it may be more likely to develop MS later in life.
Smoking: Tobacco use has been linked to increased MS risk, particularly for those who already carry genetic markers for the condition.
Childhood Obesity: Some studies suggest that being significantly overweight in early life may also raise the risk, possibly by affecting the immune system development.

How Is Multiple Sclerosis Diagnosed and Managed?

Although there is no cure for MS yet, there are many ways to manage it and help people feel better:

Medication Management: Some supplements or medications can help lower the number of relapses and may slow down how fast symptoms get worse. These treatments are often used long-term to help manage the condition over time.
Steroids: Steroids are often used during a relapse. They help calm the inflammation in the brain or spinal cord, which can shorten the length of an attack.
Physical Therapy: Exercise and movement programs led by a therapist can help with balance, strength, and flexibility. This can make daily activities easier and help with muscle stiffness or weakness.
Lifestyle Support: Healthy daily habits are very important. Getting enough sleep, staying active, eating a balanced diet, and finding ways to manage stress can all improve how a person feels and lives with MS.