Summary

The clinical phenotype in cerebral autosomal dominant arteriopathywith subcortical infarcts and leucoencephalo-pathy (CADASIL), an autosomal dominant cerebral arteriopathy, is variable, but the reasons for this remain uncertain.Possible factors include themutation site and the influence of additional modulating factors, which could include both epistatic interactions and interactions with cardiovascular risk factors known to cause sporadic small vessel disease. In a large prospectively recruited cohort of CADASIL subjects we determined relationships between phenotype and mutation site, the apoE genotype and cardiovascular risk factors. In addition to clinical fea-tures, disease severity was assessed by MRI lesion volume, measured both semiquantitatively (Scheltens scale) and quantitatively. One hundred and twenty-seven CADASI