The ultimate goal of this study is the holistic study of all mutations occurring in Notch3, with an emphasis on the EGF region and the CADASIL syndrome, in order to identify specific patterns of mutagenesis in the EGF-repeats that may be related to the clinical phenotype, sex, and age data of the various patients [38,39,44,45,46]. This evidence concerns the gene EGF and cerebral arteriopathy, autosomal dominant, with subcortical infarcts and leukoencephalopathy, type 1.