Inclusion criteria

• Suspected familial SVD
• Family history of SVD, with at least two affected first-degree family members
• Onset of symptoms of SVD before 60 years of age in at least 1 affected family member

Exclusion criteria

• Identified mutation in gene known to cause monogenic SVD (e.g. NOTCH3 mutation)

All participants need to contribute is a blood sample and phenotypic information from their clinical records.
Data can be collected by phone and blood sent through the post, or in a research clinic at one of the recruitment sites within the UK.