Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an adult onset cerebral small vessel disorder caused by the mutations of the neurogenic locus notch homolog protein 3 (NOTCH3) gene. The gene discussed is NOTCH3; the disease is cerebral arteriopathy with subcortical infarcts and leukoencephalopathy.