Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopa- thy is characterized by subcortical infarcts, dementia, migraine headaches, and white matter changes that are readily apparent on brain magnetic resonance imaging (MRI).83 Cerebral autoso- mal-dominant arteriopathy with subcortical infarcts and leuko- encephalopathy is caused by any one of a series of mutations in Genetic testing for NOTCH3 mutations is available. Retinal vasculopathy with cerebral leukodystrophy is caused by mutation in the TREX1 gene, a DNA exonuclease involved in the response to oxidative DNA damage.85 Mutations in the COL4A1 gene can cause leukoaraiosis and microbleeds and can present with ischemic or hemorrhagic stroke or as the hereditary angiopathy with nephropathy, aneurysm, and muscle Fabry disease is a rare inherited disorder that can also lead to ischemic stroke. It is caused by lysosomal -galactosidaseA deficiency, which causes a progressive accumulation of globo- triaosylceramide and related glycosphingolipids.88 Deposition affects mostly small vessels in the brain and other organs, although involvement of the larger vessels has been reported. Enzyme replacement therapy appears to improve cerebral ves- sel function. Two prospective, randomized studies using human recombinant lysosomal -galactosidase A found a reduction in microvascular deposits and reduced plasma levels of globotri- These studies had short follow-up periods, and no reduction in stroke incidence was found. 