Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL, OMIM NO.125310) is a cerebral small vessel disease caused by mutations in the NOTCH3 gene (Joutel et al., 1996). The gene discussed is NOTCH3; the disease is cerebral arteriopathy with subcortical infarcts and leukoencephalopathy.