Two Japanese CADASIL families exhibiting Notch3 mutation R75P not involving cysteine residue

Most previously reported mutations in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) result in an odd number of cysteine residues within the epidermal growth factor (EGF)-like repeats in Notch3. We report here R75P mutation in two Japanese CADASIL families not directly involving cysteine residues located within the first EGF-like repeats. Probands in both families had repeated episodes of stroke, depression, dementia as well as T2 high-intensity lesions in the basal ganglia and periventricular white matter, but fewer white matter lesions in the temporal pole on MRI. These families provide new insights into the diagnosis and pathomechanisms of CADASIL.