NOTCH3 and CADASIL: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the most common monogenic form of stroke, and is caused by mutations in the NOTCH3 gene.[1] Although pathological changes can be seen in both systemic and cerebral vessels, clinical features of CADASIL are confined to the central nervous system, causing subcortical lacunar infarcts and cognitive impairment progressing to vascular dementia.[2]