Most cases of vascular dementia are not directly inherited. Unlike some forms of Alzheimer’s disease, vascular dementia typically results from a combination of lifestyle factors, cardiovascular health, and aging rather than a single gene passed down through families. That said, genetics play a real role in two important ways: rare inherited conditions can directly cause vascular dementia, and common gene variants can raise your overall risk.
How Genetics Factor Into Vascular Dementia
Vascular dementia happens when blood flow to the brain is repeatedly disrupted, usually through small strokes or damage to tiny blood vessels. The conditions that lead to this damage, like high blood pressure, diabetes, and high cholesterol, tend to run in families. So while you’re unlikely to inherit vascular dementia itself, you can inherit a higher likelihood of developing the cardiovascular problems that cause it.
There are also rare genetic conditions that directly damage brain blood vessels and lead to dementia, sometimes at surprisingly young ages. These single-gene disorders account for a small proportion of all vascular dementia cases, though researchers believe their true prevalence is underestimated because they often go undiagnosed.
CADASIL: The Most Common Inherited Form
The best-known hereditary cause of vascular dementia is CADASIL, short for Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy. It’s caused by mutations in a gene called NOTCH3 and follows a dominant inheritance pattern, meaning you only need one copy of the mutated gene from one parent to develop the condition. If a parent carries the mutation, each child has a 50% chance of inheriting it.
CADASIL causes recurrent small strokes that damage the brain’s white matter over time. Symptoms often begin in a person’s 30s or 40s, which is much earlier than typical vascular dementia. Early warning signs include frequent migraines (often with visual disturbances), mood changes, and apathy. As the disease progresses through repeated strokes, it leads to a steady cognitive decline that eventually reaches dementia. The relatively young onset and the pattern of migraines followed by strokes are key features that distinguish CADASIL from the more common, non-inherited forms of vascular dementia.
CARASIL: A Rarer Recessive Form
A related but much rarer condition called CARASIL follows a different inheritance pattern. It’s caused by mutations in a gene called HTRA1 and is autosomal recessive, meaning a person needs to inherit a defective copy from both parents to develop the full disease. If both parents are carriers, each child has a 25% chance of being affected, a 50% chance of being an unaffected carrier, and a 25% chance of inheriting no mutations at all.
The HTRA1 gene normally helps regulate a signaling pathway involved in blood vessel health. When both copies are mutated, that regulation fails. The result is progressive damage to small arteries in the brain: thickening of vessel walls, loss of smooth muscle cells, and scarring that restricts blood flow. Over time, this causes the same kind of white matter damage and cognitive decline seen in CADASIL, though CARASIL also tends to cause hair loss and spinal problems that can help doctors recognize it.
The APOE Gene and Vascular Dementia Risk
Beyond these rare single-gene disorders, a more common genetic factor influences vascular dementia risk in the broader population. The APOE gene, well known for its link to Alzheimer’s disease, also affects vascular dementia. Everyone carries two copies of APOE, and each copy can be one of three variants: e2, e3, or e4. The e4 variant is the one that raises risk.
A large population study from Cache County, Utah found that carrying one copy of the e4 variant raised vascular dementia risk by about 60%, while carrying two copies (one from each parent) raised it more than fourfold. When researchers grouped all e4 carriers together, regardless of how many copies they had, the overall risk was roughly 85% higher than for people with no e4 variants. This gene variant alone accounted for nearly 20% of all vascular dementia cases in the study population.
What makes this finding particularly striking is that the increased risk persisted even after researchers accounted for the usual cardiovascular culprits: high blood pressure, diabetes, high cholesterol, prior strokes, and heart attacks. In other words, APOE e4 appears to raise vascular dementia risk through some mechanism beyond its effect on traditional cardiovascular risk factors. Carrying the e4 variant doesn’t mean you’ll develop vascular dementia, but it does mean your baseline risk is higher than average.
How This Compares to Alzheimer’s Heritability
Alzheimer’s disease has a stronger genetic component than vascular dementia overall. Twin studies estimate Alzheimer’s heritability at roughly 55% to 61%, meaning genetics explain more than half the variation in who develops the disease. Estimates across different study types range widely, from as low as 3% to as high as 79%, depending on methodology, but family-based studies consistently point to a substantial genetic influence.
No equivalent large-scale heritability estimate exists for vascular dementia. The genetic contribution is generally considered smaller because the disease depends so heavily on cardiovascular health, which is shaped by diet, exercise, smoking, and other modifiable factors. The inherited component is real but sits alongside, and often behind, these lifestyle influences.
When Family History Matters Most
Certain patterns in a family’s medical history raise the possibility of an inherited form of vascular dementia. The most important red flags are strokes or dementia occurring before age 60, especially if multiple family members across generations are affected. A family pattern of early migraines followed by strokes in midlife is particularly suggestive of CADASIL.
For the more common, non-inherited form of vascular dementia, a family history of high blood pressure, stroke, or diabetes is still relevant. These conditions have their own genetic components, so a strong family history of cardiovascular disease means your risk of eventually developing vascular dementia is higher than someone without that history. The difference is that these risks are modifiable. Managing blood pressure, blood sugar, and cholesterol can substantially reduce the likelihood of vascular damage to the brain, even if your genetic starting point is less favorable.
If you have a family member who developed vascular dementia before age 60, or if multiple relatives have had unexplained strokes at young ages, genetic testing for conditions like CADASIL may be worth discussing with a specialist. For most people with a family history of later-onset vascular dementia, the more productive focus is on the cardiovascular risk factors you can control.