NOTCH3 and cerebral arteriopathy, autosomal dominant, with subcortical infarcts and leukoencephalopathy, type 1: Mutations were considered potentially pathogenic if patients had: (a) typical clinical CADASIL syndrome; (b) diffuse white matter hyperintensities; (c) the 33 NOTCH3 exons analyzed; (d) mutations that were not polymorphisms; and (e) Granular osmiophilic material (GOM) deposits in the skin biopsy.