Awareness & Education
Increase recognition of CADASIL among physicians, patients, and the public — closing the diagnostic gap with accessible, accurate resources.
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A Hidden Genetic Cause of Stroke
Recognized early.
Recognized early.
Researched fully.
Supported globally.
CADASIL is the most common inherited cause of stroke in adults — yet it is consistently missed, misdiagnosed, and under-researched. We exist to change that. For patients. For families. For every clinician who deserves the right information at the right moment.
Donations processed by the Sunnybrook Foundation, supporting CADASIL research at Sunnybrook.
2–5
Estimated cases per 100,000 (likely higher)
1 gene
NOTCH3 — chromosome 19p13
50%
Inheritance risk per child of a parent with CADASIL
~1 in
UK Biobank estimate of population NOTCH3 carrier frequency
+
Distinct NOTCH3 pathogenic variants identified
–
Age range most commonly reported for stroke events
cures
Disease-modifying therapies — yet
What is CADASIL
A rare disease of the brain's smallest blood vessels.
CADASIL — Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy — is a hereditary condition caused by changes in the NOTCH3 gene. CADASIL affects the small arteries deep in the brain and can cause migraine with aura, strokes, mood or cognitive changes, and other neurological symptoms. How CADASIL affects each person can vary considerably.
CADASIL can look very different from person to person
Some people develop neurological symptoms relatively early, while others experience mild symptoms or remain largely unaffected until much later in life. Even people within the same family who share the same variant can experience CADASIL differently.
- The most common inherited (monogenic) cause of stroke in adults
- Autosomal dominant — each child of a parent with CADASIL has a 50% chance of inheriting the variant
- Diagnosis brings together clinical assessment, brain MRI, and NOTCH3 genetic testing (with genetic counselling)
- Often mistaken for MS, atypical migraine, or "early dementia"
Four pillars. One mission. A coordinated response.
We are organized around the levers that change outcomes for people living with CADASIL — from the moment a symptom appears to the day a therapy reaches them.
Research Connection
Awareness work that supports earlier diagnosis, and pointing patients and families toward CADASIL research opportunities as we come across them.
Explore →Patient & Family Support
Honest, practical guidance for people newly diagnosed and the partners, parents, and children walking with them — grounded in the experience of people who have lived it.
Explore →Advocacy & Partnerships
Speaking up for CADASIL in stroke and rare-disease communities, and working alongside organizations that help more people find the right conversation at the right time.
Explore →The pattern that should raise suspicion.
CADASIL is often missed or misdiagnosed for years. The clinical pattern is recognizable when clinicians know what to look for — and when several suggestive features appear together, CADASIL should be on the differential.
Migraine with aura — early
Often the first symptom, presenting in the 20s–30s. Visual or sensory aura that may be prolonged or atypical.
Learn more →Stroke / TIA before age 60
Recurrent small, deep strokes or TIAs (mini-strokes) — often without classic vascular risk factors. A hallmark of mid-life CADASIL.
Learn more →Mood & cognitive change
Apathy, depression, and progressive subcortical cognitive impairment — often misattributed to stress or "burnout."
Learn more →White matter on MRI
Confluent T2/FLAIR hyperintensities — especially in the anterior temporal lobes and external capsules — can strongly raise suspicion for CADASIL. Imaging findings vary and are not diagnostic on their own.
Learn more →A telling family history
Multiple relatives across generations with strokes, "early dementia," or unexplained migraine — autosomal dominant inheritance.
Learn more →Genetic testing — with counselling
NOTCH3 sequencing can confirm CADASIL. Because a positive result can have personal and family implications, testing is best paired with informed clinical and genetic counselling.
Learn more →The CADASIL diagnostic pathway.
A structured approach — clinical assessment, brain MRI, and, where appropriate, genetic testing — turns a confusing presentation into a working diagnosis. How long the pathway takes varies depending on access to imaging, specialists, and genetic counselling.
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Recognize the pattern
Stroke or migraine with aura in a younger adult, mood or cognitive change, plus a suggestive family history. Pattern recognition is the first — and most missed — step.
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Image the brain
Brain MRI is an important part of the evaluation. Certain patterns of white-matter change can raise suspicion for CADASIL, but MRI findings vary — and MRI also helps investigate other possible explanations for the same symptoms.
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Discuss genetic testing
Identification of a pathogenic NOTCH3 variant can confirm CADASIL. Because a result can have implications for the individual and their family, testing is best framed by an informed clinical discussion and, where available, genetic counselling.
Where research is heading
Explore research initiatives
The science is moving — and so are we.
Because CADASIL usually changes over many years, researchers need better ways to measure disease activity and change over shorter periods. Identifying reliable biomarkers could help researchers understand differences in disease expression and eventually evaluate whether future therapies are working.
At Sunnybrook, Dr. Rick Swartz and his team are developing high-resolution 7 Tesla MRI approaches to investigate potential imaging biomarkers in cerebral small-vessel diseases, including CADASIL.
Biomarkers under investigation
Potential imaging biomarkers, blood-based markers (e.g. NfL), and tissue-based approaches — all in active research.
Therapeutics
Antisense oligonucleotides and gene-targeted strategies in early-phase development.
Cohorts & natural history
Well-characterized patient cohorts and longitudinal follow-up to build the evidence base for future trials.
Models
iPSC-derived vascular cells supporting mechanistic discovery.
Patient & family support
You are not navigating CADASIL alone.
CADASIL touches generations. We connect patients, partners, children, and caregivers with peer community, vetted information, and the practical tools to advocate for the care they deserve.
- Curated guides for newly diagnosed individuals and at-risk relatives
- Templates for talking to your physician, employer, and insurer
- Connections to genetic counsellors and CADASIL-aware clinicians
- Family planning & predictive testing decision support
For years, my migraines were dismissed as stress and my mother's "early dementia" was never explained. A single MRI and a genetic test connected three generations of our family — and finally gave us a name.
— A CADASIL family member, Ontario
Answers to the questions we hear most.
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy. It is a hereditary disease of the small blood vessels of the brain, caused by mutations in the NOTCH3 gene.
No. CADASIL is the underlying genetic disease that causes recurrent strokes and other neurological symptoms. It is the most common monogenic cause of stroke in adults — but stroke is one of several manifestations.
Autosomal dominant. Each child of a parent with CADASIL has a 50% chance of inheriting the pathogenic NOTCH3 variant. Severity can vary even within the same family.
No treatment currently reverses or specifically stops CADASIL. Care generally focuses on managing symptoms, addressing modifiable vascular risk factors, applying established stroke-prevention principles where appropriate, and considering individual medication and procedure decisions with a CADASIL-aware clinical team. Several therapeutic strategies are in early-stage development.
Predictive testing is a deeply personal decision. We strongly recommend pre-test genetic counselling. Knowing your status can guide vascular risk management and family planning — but should always be a choice, not a demand.