Cerebral autosomal dominant arteriopathy with subcortical infarcts andleukoencephalopathy (CADASIL) is the most common monogenetic small vessel diseaseand results in stroke and cognitive impairment.1 CADASIL is caused by mutations of NOTCH3, which codes for areceptor expressed in vascular smooth muscle cells and pericytes,2 involved in regulation of cerebral blood flow (CBF).3 Although clinical manifestations are confined to the brain, arteriopathy isdetected throughout the body.4 The gene discussed is NOTCH3; the disease is CADASIL.