HTRA1 and CARASIL: Missense and nonsense HTRA1 variants have been reported in cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL).19 Recently, heterozygous variants have also been identified in patients with an autosomal dominant form of SVD.20,21 Eight heterozygous missense variants and 1 nonsense HTRA1 variant were identified in 12 individuals (1.3%, 95% CI 0.7%–2.2%).