Cerebrovascular diseases (CVDs) are one leading cause of morbidity and mortality worldwide. Despite intensive investigations, more than 30% of strokes remain of undetermined origin. Rare Cerebrovascular Diseases (rCVDs), including heritable (i.e., CADASIL, COL4A1 syndrome, Fabry disease) and acquired conditions (i.e., Sneddon syndrome, Moyamoya arteriopathy) account for a proportion of these strokes. However, rCVDs are often misdiagnosed since clinicians are not able to recognize them. Although rare, the identification of these stroke causes is important to establish appropriate management measures, including genetic counselling, and, if available, therapy. The lack of data on phenotype and clinical course of rCVDs, given the paucity of published series, makes the diagnosis and the development of therapies challenging. Furthermore, the molecular characterization of rCVDs is still lacking, despite progresses achieved in common stroke by applying high throughput approaches as multi-omics. Since the diagnosis and care of rCVDs require adequate expertise and instrumental tools, clinical and research activities are usually reserved to few specialized centers, mostly located in the North of Italy, leading patients to expensive trips for consultations. Therefore, the creation of a clinical and research network aimed at improving the diagnostic pathways of rCVDs is highly needed to improve the number of patients with rCVDs to better define the clinical phenotype and to transfer the knowledge on rCVDs in other centers overall Italy filling the geographical gap affecting Southern Italy.

Inclusion Criteria:

• patients with a clinical, genetic and/or neuroradiological diagnosis of rCVD (CADASIL, Fabry's disease, COL4A1, Sneddon's syndrome or Moyamoya arteriopathy), who have had at least one brain MRI study;

Exclusion Criteria:

• na

Adults, male and female patients affected by a Rare Cerebrovascular Disease (rCVD)