NOTCH3 and cerebral arteriopathy with subcortical infarcts and leukoencephalopathy: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare monogenic hereditary cerebrovascular disorder that can cause stroke in adults due to mutations in the NOTCH3 gene and is associated with characteristic white matter changes on imaging (the "NOTCH" part of the gene name is derived from the <i>Drosophila melanogaster</i> notched wing mutant, and "3" signifies that it is the third discovered human homologue).