Multiple Sclerosis

This review summarises two decades of genetic research in multiple sclerosis. Risk is highly polygenic: genome-wide studies have identified 233 common variants, 201 of them outside the major histocompatibility complex, the immune region long known to carry the strongest signal. Most point to immune regulation rather than the brain itself. The authors distinguish variants that affect whether someone develops the disease from those that may modify its course, and set out the questions still unanswered.

Epstein-Barr virus infection is the strongest known environmental risk factor for multiple sclerosis, but which immune genes connect the two has stayed unclear. This study combined gene activity measured separately in 14 immune cell types with genetic studies of both MS and an EBV-related condition. It prioritised 43 candidate genes supported from both directions, then checked which of them existing drugs already target. The result is a shortlist for testing, not a finding about treatment.

Multiple sclerosis starting at or after age 50 is increasingly recognised, and it was not clear whether it has different causes from the usual adult-onset form. This Swedish study compared 396 late-onset and 3,554 adult-onset cases against 7,340 controls. The established risk factors, including family history, the HLA-DRB1*15:01 gene variant, Epstein-Barr antibody levels, smoking and low sun exposure, applied to both groups, though more strongly in the younger-onset one.

More than 230 genetic variants are linked to developing multiple sclerosis, but only one to how it progresses. Environmental factors such as low vitamin D and obesity are also implicated. This review examines what happens when the two are analysed together, using methods like Mendelian randomisation that use genetic data to test whether an environmental factor is a cause rather than a coincidence. Evidence for direct interaction between specific genes and exposures has so far been limited.

Epstein-Barr virus is strongly linked to developing multiple sclerosis, but its role after diagnosis is less clear. Using 5,706 patients from two Swedish population studies followed in the national MS registry, researchers tested whether antibody levels against one viral protein, EBNA1, predicted disability progression, and whether carrying particular immune genes changed that relationship. The analysis focused on two HLA types, A*02:01 and DRB1*15:01, which are already known to raise or lower MS risk.

Few things people can change are known to affect the risk of developing multiple sclerosis. Using UK Biobank records for 486,908 adults aged 37 to 70 who had no neurological disease at the start, this study followed them for a median of 13.5 years and compared those who reported taking vitamin C supplements with those who did not. The analysis also accounted for each person's inherited susceptibility, to see whether any effect differed by genetic risk.

Genetic risk factors for multiple sclerosis are well mapped, but which circulating proteins actually cause disease is not. This study used Mendelian randomisation, which uses inherited variants that control protein levels to test whether a protein has a causal effect rather than merely accompanying illness. Drawing on four large datasets linking genetic variants to plasma protein levels, the authors identified four proteins with significant causal associations with either developing multiple sclerosis or how severe it becomes.

This study used Mendelian randomization, a method that uses naturally inherited genetic differences to test whether something actually causes a disease rather than simply occurring alongside it. Drawing on large genetic datasets from the International Multiple Sclerosis Genetics Consortium and blood cell studies, the researchers examined whether particular white blood cell traits drive multiple sclerosis risk. Because the genetic variants a person carries are fixed from birth, this design avoids much of the confusion that affects ordinary observational studies.

Human genes shape only about 5% of which bacteria live in the gut, but that small share can still point at disease mechanisms. Comparing genetic studies of multiple sclerosis with studies of gut bacteria, researchers found the same genetic signal linked both to MS and to levels of a gut microbe, sitting in the FcRL3 gene. The MS-associated version lowers FcRL3 protein and changes how B cells process the gene as they mature.

Infection with Epstein-Barr virus is now recognized as a major risk factor for multiple sclerosis. This computational study combined gene activity data from MS patients, the fingerprint the virus leaves on gene activity, and genes flagged by genetic risk studies, then screened existing approved drugs for ones that might act on the resulting targets. Nothing here has been tested in people, but repurposing an approved drug is usually faster than developing a new one, particularly for progressive disease.

Smoking and certain immune-system genes each influence multiple sclerosis, and this Swedish study of 6,807 patients asked whether they interact to affect disability progression. Followed for up to 15 years, smokers faced a higher risk of worsening disability mainly if they lacked the HLA-A*02:01 gene variant; among carriers of that variant, smoking showed no clear effect. No interaction was seen with the well-known HLA-DRB1*15:01 risk gene. The findings suggest a person's immune-gene background shapes how much smoking harms their MS course, reinforcing that quitting matters.

Earlier genetic studies had linked the ataxin-1 gene, better known for a hereditary ataxia, to multiple sclerosis risk. This work follows up on what the gene actually does in B cells during autoimmune demyelination in mice. Reading gene activity, chromatin access and proteins from the same cells, the team found ataxin-1 concentrated in several specific B cell subsets and involved in how RNA is spliced and translated rather than in how chromatin is remodelled.

Interleukin-1 genes help control inflammation in multiple sclerosis and also influence how the brain repairs and adapts. Genetic studies have concentrated on who develops the disease rather than who recovers function. This study tested four common variants in interleukin-1 genes in 162 people with multiple sclerosis undergoing rehabilitation, asking whether genotype relates to how much function they regained. If it does, inherited differences may partly explain why rehabilitation helps some people more than others.

Most genetic knowledge about multiple sclerosis comes from European-ancestry studies, which may not fit other populations. This scoping review gathers the scattered evidence on MS genetics in Gulf Cooperation Council countries, where distinctive ancestry, high rates of marriage between relatives, and widespread vitamin D deficiency shape risk. It maps what is known about HLA and non-HLA genes, vitamin D pathways, and family patterns, while noting the evidence is still too limited for firm conclusions. The authors outline research priorities to build toward precision neurology for these underserved populations.

Most known genetic risk for multiple sclerosis sits in the HLA region, but this work looks instead at mitochondrial DNA, which is inherited from the mother. Pooling published studies from Arab and Near Eastern populations, the authors examine whether a mitochondrial group called haplogroup U is more common in people with relapsing remitting MS. This is a preprint, meaning it has not yet been reviewed by other scientists, and the underlying studies are small, so the finding needs confirmation.

People with MS differ widely in how the disease behaves, partly because of differences in their genetic makeup. Using brain tissue donated by 287 people with MS, researchers examined whether specific tissue features tied to a person's genetic background relate to the mix of lesion types and to how severe their disease was. Connecting inherited differences to what is actually seen in the brain helps explain why MS varies so much between individuals and could improve how doctors predict its course.

The strongest known genetic risk factor for developing MS is a version of the immune gene HLA called DRB1*15:01, which roughly triples susceptibility. But whether it also speeds up the disease once it begins has been debated. Pooling 56 studies covering more than 22,000 people, this review found only a modest, inconsistent link between HLA variants and MS progression. The work clarifies that genes which raise the risk of getting MS don't necessarily determine how fast it advances.

A man treated for what looked like rapidly worsening multiple sclerosis turned out to carry a change in the CSF1R gene, causing an ultra-rare inherited condition that damages brain white matter. Genetic testing was ordered only because he deteriorated so fast despite treatment. The change sits in the part of the receptor that does its signalling work and had been reported in just one patient before. It is listed here as a genetic condition that can be mistaken for MS.

The variant rs10191329 was the first gene change linked to how severe multiple sclerosis becomes, thought to reflect the brain's resilience. This UK Biobank study asked whether it also affects thinking, in people with MS and beyond. Testing reaction time, reasoning, and memory, the researchers found weak but consistent links between the risk version and slightly poorer cognition in healthy controls, with similar non-significant trends in MS, Parkinson's, and dementia. The results support the idea that this variant shapes MS outcomes by influencing overall brain health.

HLA-DRB1*15:01 is the single strongest genetic risk factor for multiple sclerosis, but exactly how it shapes the brain's immune environment is unclear. Researchers used mice engineered to carry the human version of this gene and followed them at 6, 9 and 15 months, comparing males and females. The gene altered how microglia, the brain's resident immune cells, behaved, and the effects differed with age and sex. That may help explain why MS affects women more often than men.

MS is a polygenic disease, many genes each add a small amount of risk, and researchers want to know which ones shape how severe it becomes. In 548 untreated Russian patients, this study tested 35 variants in immune-system genes against a standard MS severity score. Variants in several genes (including CCR5 and the major risk gene HLA-DRB1) were linked to severity. Findings like these move toward genetic tools that could one day help predict an individual's likely disease course.

Multiple sclerosis risk is shaped by both genes and environment, and treatments that work well for one person may not for another. This review pulls together what's known about the genetics of MS, more than 200 risk regions in the genome, with the HLA-DRB1*15:01 immune gene the strongest, alongside epigenetic changes (chemical marks that switch genes on or off) and environmental triggers like Epstein-Barr virus. The goal is more personalized MS care, using a person's genetic and molecular profile to guide which disease-modifying therapy is most likely to help.

Adult onset genetic white matter diseases are often mistaken for multiple sclerosis because they look similar on scans. The White Matter Rounds Network, clinicians from more than 15 centers who meet monthly to discuss undiagnosed cases, surveyed what MRI protocols centers actually use and found little consistency. Using a structured expert process, they propose a core standard scan protocol. Consistent imaging makes it more likely that an inherited leukodystrophy is recognized rather than treated for years as MS.

The choroid plexus, a structure that makes spinal fluid, enlarges early in MS. Studying 727 patients and 461 healthy people, researchers modeled how its size changes across the lifespan and linked enlargement to clinical features, MRI findings, and genetic risk, including HLA and broader polygenic risk scores. Tying a measurable brain structure to inherited MS risk could yield new ways to identify higher-risk patients and understand how genetic susceptibility plays out in the brain.

In multiple sclerosis the immune system attacks the brain, but exactly what it targets has been hard to pin down. This study focused on people who carry HLA-DR15, the immune-gene variant most strongly tied to MS risk, and searched for pieces of a protein called RASGRP2 that their immune cells recognize. Identifying such gene-linked targets is a step toward "tolerising" therapies designed to calm the specific immune response in genetically susceptible patients, a more precise alternative to broadly suppressing immunity.

Why multiple sclerosis progresses faster in some people than others may partly reflect their genes. Researchers genotyped 845 MS patients (relapsing-remitting and progressive) for variants in genes that defend cells against oxidative stress and a form of cell death called ferroptosis, both linked to nerve damage in MS. By testing whether these variants track with the progressive form of the disease, the study looks for inherited factors that influence severity, which could eventually help identify who is at greater risk of worsening.

Genome studies have found hundreds of DNA regions that raise multiple sclerosis risk, but not how they actually cause disease. This review explains how scientists are connecting those risk variants to biology, especially by mapping which variants change how genes are switched on in specific immune cells, and how genetic and environmental risks (like Epstein-Barr virus) may converge on shared pathways. Turning a list of risk genes into real mechanisms is essential for designing treatments that target the roots of MS rather than only its symptoms.

Multiple sclerosis and type 1 diabetes are both autoimmune diseases and sometimes occur in the same person or family, hinting at shared genetic roots. Using large genetic datasets (nearly 15,000 MS patients and many more for diabetes), researchers looked for DNA regions that influence both conditions and identified 26 shared signals. Understanding this common "autoimmunity" genetics helps explain why these diseases cluster together and could point to treatments or prevention strategies that work across more than one autoimmune condition.

The immune signaling molecules IL-18 and IL-8 help drive the inflammation seen in multiple sclerosis, and small inherited differences in their genes might affect who develops MS and how active it is. This study compared 98 people with relapsing-remitting MS to 98 healthy volunteers, looking at variations in these two genes and relating them to disease susceptibility, disability scores, and MRI activity. Findings like these add to the picture of how a person's immune-gene makeup shapes their individual course of MS.

Why do genes that raise MS risk persist, and why is MS more common in northern Europe? This review examines two ideas in light of ancient-DNA research. One holds that MS risk variants survived because they once strengthened defenses against infection; the other, that modern low exposure to ancient microbes leaves the immune system prone to overreacting. Recent findings tie higher MS genetic risk to ancestry from Bronze Age Steppe peoples who evolved strong inflammatory immune responses. It is an accessible look at the deep history behind today's genetic risk.

Two decades of large genetic studies have reshaped how doctors understand multiple sclerosis. This review explains that MS risk is highly polygenic, spread across more than 200 regions of the genome, with the immune gene HLA-DRB1*15:01 remaining the single strongest and most reproducible risk factor. Beyond that, many other immune-related genes contribute, and rarer variants in genes such as PRF1, CYP27B1, and NLRP1 are emerging from family-based studies. The authors stress the need to study people of diverse ancestries to understand MS risk fully.

Scientists have long known that many small genetic differences add up to influence who develops multiple sclerosis. This expert review summarizes where the field stands now: beyond the well-mapped genes that shape susceptibility (mostly immune-related), researchers have found the first genetic signal tied to how fast MS progresses (the DYSF-ZNF638 region), which points to processes inside the brain and spinal cord rather than the immune system. It also highlights how host genes and the Epstein-Barr virus interact, reframing how MS may begin.