Is Multiple System Atrophy (MSA) Hereditary?

Multiple system atrophy is not inherited in any straightforward way. The disease is classified as sporadic, meaning it appears without a clear family pattern and a positive family history actually counts against the diagnosis in current clinical criteria. Yet the picture has grown more complicated over the past decade as researchers have identified specific genetic variants that raise the risk of developing MSA, along with epigenetic changes in brain tissue that may push the disease forward. The honest answer is that MSA is not hereditary the way Huntington’s disease is hereditary, but genes are not irrelevant either.

Why MSA Is Called a Sporadic Disease

MSA typically strikes in middle age or later and progresses over roughly six to ten years. It involves the degeneration of multiple brain systems at once, producing some combination of parkinsonism (stiffness, slowness), cerebellar problems (poor coordination and balance), and severe dysfunction of the autonomic nervous system (blood pressure drops on standing, bladder problems, and other involuntary functions going haywire). The term “multiple system atrophy” was coined in 1969 to unify several conditions that had been described separately, including striatonigral degeneration and olivopontocerebellar atrophy, recognizing that these were overlapping expressions of the same underlying process.¹

The disease comes in two recognized motor subtypes. MSA-P is dominated by parkinsonian features, while MSA-C is dominated by cerebellar dysfunction.² In Western populations, MSA-P is more common; in East Asian populations, MSA-C tends to predominate. Despite this variation, both subtypes share the same hallmark under the microscope: abnormal clumps of the protein alpha-synuclein accumulating inside oligodendrocytes, the cells that insulate nerve fibers in the brain’s white matter.³

Crucially, most people diagnosed with MSA have no affected relatives. Familial clusters are rare enough that when they do turn up, clinicians are expected to question the diagnosis and consider inherited conditions that can look like MSA.⁴ That is why the disease remains classified as sporadic. But “sporadic” does not mean “zero genetic involvement.” It means no single gene mutation is sufficient to cause the disease in a predictable inheritance pattern.

Genetic Variants That Raise the Risk

Several lines of genetic research have chipped away at the idea that MSA is purely a matter of bad luck. The gene that has attracted the most attention is SNCA, which encodes alpha-synuclein itself. A large study combining multiple datasets found that common variants near SNCA were strongly associated with MSA risk, with an odds ratio of about 6.⁵ That is a substantial effect size for a common genetic variant, and it makes biological sense: if the disease is defined by alpha-synuclein going wrong in brain cells, then variations in the gene that produces alpha-synuclein plausibly tip the scales.

A separate discovery came from Japan, where researchers found mutations in COQ2, a gene involved in producing coenzyme Q10, in two families with multiple affected members. Beyond those rare families, a more common COQ2 variant (V343A) also showed up at higher rates in people with sporadic MSA.⁶ Coenzyme Q10 is essential for energy production in mitochondria, and MSA brains have been shown to have reduced activity in parts of the mitochondrial energy chain, which fits with the idea that impaired CoQ10 function could leave cells vulnerable to damage.⁷

The most recent and largest genome-wide study of MSA, published in 2024, identified several new risk loci. Under a standard analysis, a variant in the GAB1 gene on chromosome 4 reached genome-wide significance, and a second locus near a non-coding RNA gene on chromosome 15 did as well. When researchers looked for variants that operate in a recessive fashion (where you need two copies to see the effect), they found a locus in the TENM2 gene on chromosome 5 with a strikingly high odds ratio of about 7.4, along with another near the RABGEF1/KCTD7 region on chromosome 7.⁸ These findings are new and need replication, but they reinforce the view that MSA has a genetic architecture, even if it is complex and does not follow simple family inheritance rules.

An earlier genome-wide study had found no loci reaching the strictest significance threshold, though it flagged several regions of interest including variants near MAPT, the gene encoding the tau protein involved in other brain diseases.⁹ The contrast between that earlier null result and the 2024 study’s significant hits largely comes down to sample size: MSA is rare (roughly 3 to 5 people per 100,000), so assembling enough cases for a well-powered genetic study took years of international collaboration.

The Alpha-Synuclein Puzzle in Oligodendrocytes

Understanding why alpha-synuclein accumulates in oligodendrocytes, rather than in neurons as it does in Parkinson’s disease, is one of the central mysteries of MSA. Oligodendrocytes are the cells that produce the myelin sheaths wrapping nerve fibers in the brain. They do not normally produce much alpha-synuclein themselves, which raises the question of where the protein is coming from and why it aggregates there so aggressively.¹⁰

Several hypotheses are in play. Alpha-synuclein might be transferred from neurons into oligodendrocytes, where it then misfolds and clumps. Alternatively, something about the MSA disease process might reactivate alpha-synuclein production in oligodendrocytes that normally keep it turned off. Research into the transcriptional profile of MSA cerebellar white matter has shown large-scale gene-expression changes, with hundreds of genes differentially expressed in the cerebellar subtype compared to controls.¹¹ These expression changes could create an environment in which alpha-synuclein is more likely to misfold and accumulate, even without a single causal mutation.

Epigenetic Changes and What They Mean

Beyond the DNA sequence itself, researchers have found that the way genes are regulated through chemical modifications (epigenetics) is altered in MSA brain tissue. The first comprehensive study of DNA methylation in MSA post-mortem brains identified 157 sites where methylation patterns differed between MSA cases and controls, with genes such as HIP1, LMAN2, and MOBP among the most affected. These changes were found in white matter regions burdened by the characteristic alpha-synuclein inclusions and were replicated in an independent group of patients.¹²

A follow-up study comparing MSA with Parkinson’s disease and progressive supranuclear palsy found substantial overlap in methylation changes across these three conditions, suggesting some shared molecular disruption in parkinsonian brain diseases.¹³ More recently, researchers have begun looking at methylation changes detectable in blood rather than brain tissue. One study found that higher methylation at specific sites within the SNCA gene was associated with increased odds of both Parkinson’s disease and MSA, with the association being stronger for MSA (about five-fold increased odds for those in the highest methylation group compared to the lowest).¹⁴

Epigenetic changes are not inherited the way mutations are, but they can be influenced by environmental exposures, aging, and cellular stress. The emerging picture is that MSA may involve a cascade in which genetic susceptibility, environmental triggers, and epigenetic shifts converge on oligodendrocytes to produce the disease. This helps explain why MSA is sporadic: the combination of factors needed is unlikely to repeat in the same family.

Environmental Risk Factors and Gene-Environment Interaction

If MSA is not straightforwardly genetic, what else contributes? A handful of case-control studies have looked at occupational and environmental exposures. An early investigation found that MSA patients reported significantly more exposure to metal dusts and fumes, organic solvents, plastic additives, and pesticides than control subjects, and the authors suggested this was consistent with the idea that environmental insults target a genetically vulnerable nervous system.¹⁵

However, a later French study did not confirm the pesticide link. That study instead found a strong association between MSA and working as a plant or machine operator, with risk increasing with years in that occupation.¹⁶ The inconsistency between studies is frustrating but not unusual for a rare disease where case-control samples are small and occupational histories are collected retrospectively. The bottom line is that environmental exposures probably play some role, but no single toxin has been reliably established as a cause. Researchers have framed the most likely scenario as a combination: certain people carry genetic variants that make their oligodendrocytes or mitochondria slightly more fragile, and environmental stressors accumulated over decades push those cells past a tipping point.¹⁷

The COQ2 Story and Population Differences

The COQ2 gene deserves its own discussion because it illustrates how genetic risk factors in MSA can be population-specific. The original COQ2 findings came from Japanese families and Japanese sporadic cases, and for a while, Western researchers questioned whether the finding would hold up outside East Asia.¹⁸ Subsequent work showed that the V393A variant in COQ2 was indeed a risk factor in Han Chinese and Korean populations as well, with a meta-analysis across multiple East Asian case-control studies showing about a two-fold increased risk overall. The association was particularly strong for the cerebellar subtype, MSA-C, where the odds ratio climbed to nearly three, while no significant association was found for MSA-P.¹⁹

In European populations, the V393A variant is extremely rare or absent, which is why attempts to replicate the COQ2 finding in Western cohorts have mostly come up empty. This does not mean the finding was wrong. It means that different populations may carry different sets of risk variants for the same disease, a phenomenon seen across many complex conditions. For someone of East Asian ancestry wondering whether their family carries MSA risk, COQ2 is the most relevant genetic lead. For someone of European ancestry, the SNCA variants and the newer GWAS loci may matter more, though the practical utility of any of these variants for individual risk prediction remains limited.

Hereditary Conditions That Mimic MSA

One reason the question “is MSA hereditary?” comes up in families is that several genuinely hereditary diseases can look almost identical to MSA clinically. The spinocerebellar ataxias (SCAs) are the most common source of confusion. These are autosomal dominant conditions, meaning each child of an affected parent has a 50% chance of inheriting the mutation. Several SCAs produce cerebellar dysfunction plus parkinsonism and autonomic problems, which is exactly the symptom profile of MSA-C.²⁰

A recently recognized condition, spinocerebellar ataxia type 27B (SCA27B), caused by a repeat expansion in the FGF14 gene, has been shown to overlap phenotypically with MSA. One study found that patients clinically diagnosed with MSA who also carried the FGF14 expansion had distinct patterns of disease progression and survival, suggesting some of them may have been misdiagnosed.²¹ Even Friedreich’s ataxia, typically a disease of childhood and adolescence, can present very late in life with minimal genetic expansion and mimic MSA-C closely enough to fool experienced neurologists.²²

This overlap has a practical implication. If you or a family member has been told the diagnosis is MSA but there is a family history of similar symptoms, genetic testing for SCAs and other hereditary ataxias is worth pursuing. The treatment options and prognosis differ, and in some cases the hereditary condition progresses more slowly. Clinicians are increasingly aware that what looks like MSA in a family cluster may actually be an inherited ataxia, and the current diagnostic criteria explicitly flag a positive family history as something that should prompt further investigation.⁴

When MSA Overlaps with Lewy Body Disease

MSA and Lewy body disease both involve alpha-synuclein going wrong, but in different cell types and with different clinical profiles. Occasionally, both pathologies show up in the same brain at autopsy. A study examining patients with this combined pathology found that five of nine cases carried either the APOE ε4 allele or a GBA gene variant, both of which are established risk factors for Lewy body disease and Alzheimer’s disease but not typically linked to MSA on its own.²³ No one in this group had a clear single-gene cause of disease, but the presence of these risk variants suggests that when MSA co-occurs with Lewy body pathology, the genetic landscape shifts to include risk factors more typical of Lewy body disease. For families dealing with a complex clinical picture that includes features of both conditions, this is relevant context.

Where Treatment Research Stands

There is no disease-modifying therapy for MSA today, but understanding the genetic and molecular underpinnings has shaped the direction of clinical trials. Most current efforts target the alpha-synuclein aggregation process, neuroinflammation, mitochondrial dysfunction, or some combination of these.²⁴ Drugs that aim to prevent alpha-synuclein from clumping, antibodies designed to clear misfolded protein, and approaches to reduce alpha-synuclein production at the gene level are all under investigation.²⁵ Stem cell therapies and gene therapies are also being explored, though most are still in early phases.

The genetic findings feed into this pipeline in a couple of ways. The COQ2 mutations, for instance, suggest that supporting mitochondrial function through coenzyme Q10 supplementation or related strategies could be worth testing, at least in patients who carry those variants. The SNCA variants reinforce the rationale for going after alpha-synuclein expression directly. And the discovery that epigenetic changes in SNCA may be detectable in blood opens the door to potential biomarkers that could identify people at risk before symptoms appear, or track whether a therapy is actually modifying the disease process.¹⁴ None of this has translated into a treatment you can get today, but the research trajectory has clearly accelerated as the genetic and epigenetic picture has sharpened.²⁶