What is the prevalence of Cadasil (Cerebral Autosomal Dominant Arteriopathy With Sub-Cortical Infarcts And Leukoencephalopathy)?

Cerebral Autosomal Dominant Arteriopathy with Sub-Cortical Infarcts and Leukoencephalopathy (CADASIL) is an underdiagnosed genetic disorder with an estimated prevalence ranging from 2 to 5 per 100,000 individuals in the general population. While often considered rare, its true prevalence is likely higher due to frequent misdiagnosis as age-related small vessel disease or common migraines.

What is the estimated prevalence and incidence of CADASIL?

Current data suggests that CADASIL is the most common hereditary cause of stroke and vascular dementia in adults. Because it is a genetic condition, the incidence is relatively stable across populations, though exact numbers are difficult to track because many individuals remain asymptomatic or undiagnosed for decades. At DiseaseMaps.org, 57 people with CADASIL have joined our community, providing a real-world perspective on the diagnostic journey and the diverse ways this condition manifests.

Does CADASIL affect genders or age groups differently?

CADASIL affects males and females with equal frequency, as the mutation occurs on the NOTCH3 gene, which is located on chromosome 19. The condition is strictly adult-onset, typically presenting between the ages of 30 and 50. While clinical symptoms are rarely seen in childhood, the underlying pathology of CADASIL begins much earlier in life.

Why is accurate prevalence data for CADASIL challenging?

Determining the exact number of people living with CADASIL is complicated by several factors:

• Misdiagnosis: Patients are often incorrectly diagnosed with late-onset migraines or general white matter disease.


• Genetic Heterogeneity: Some individuals carry the mutation but show very mild or atypical symptoms.


• Lack of Screening: Because CADASIL symptoms mimic common stroke risk factors, clinicians may not always order the specific genetic testing required for confirmation.

Are there geographic or ethnic variations in CADASIL?

While CADASIL was originally identified in European families, it is now recognized as a global condition. There is no evidence suggesting it is restricted to specific ethnic groups, although under-reporting in certain regions may create the illusion of geographic rarity. As genetic screening becomes more accessible worldwide, the number of identified CADASIL cases continues to rise.

Next steps

• Consult a neurologist specializing in neurovascular disorders or a clinical geneticist for formal testing.


• Join the DiseaseMaps.org community to connect with other patients and caregivers navigating the condition.


• Request a referral to a center of excellence that focuses on small vessel diseases and genetic stroke syndromes.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• Orphanet: Cerebral Autosomal Dominant Arteriopathy with Sub-Cortical Infarcts and Leukoencephalopathy (ORPHA:136).


• NIH Genetic and Rare Diseases Information Center (GARD): CADASIL.


• OMIM (Online Mendelian Inheritance in Man): #125310 - Cerebral Autosomal Dominant Arteriopathy with Sub-Cortical Infarcts and Leukoencephalopathy.


• The CADASIL Foundation: Patient resources and educational materials.