Several different mutations have been reported in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). We present a unique case with transversion not involving cysteine on neurogenic locus notch homolog protein 3 gene. We present a case of 65-year-old woman with new ischemic stroke resulting in right hemiparesis. She has previously suffered minor strokes at age 56, 58, and 60 years and migraine headaches between age 10 and 50 years. Magnetic resonance imaging demonstrated multifocal chronic ischemic infarctions with encephalomalacia in the left posterior parietal, parieto-occipital regions and the pons. An analysis of the protein sequence of notch 3 gene did not demonstrate any alterations characteristics of CADASIL disease. There was a deoxyribonucleic acid variant with transversion of alanine with tyrosine and change of histidine with leucine on notch 3 gene. None of the family members had any clinical manifestations suggestive of CADASIL. We report the first report of deoxyribonucleic acid variation in notch 3 gene associated with clinical features of CADASIL without any familial component.