CADASIL is an inherited disorder caused by mutations in the "Notch" 3 gene located on chromosome 19. The "Notch" 3 gene codes for a transmembrane protein whose function is not well-known. However, the mutation causes accumulation of this protein within small to medium-sized blood vessels. This disease often presents in early adulthood with migraines, stroke, mood disturbances, and cognitive deterioration. MRI shows white matter changes in the brain and also signs of repeated strokes. The diagnosis can be confirmed by gene testing.