Genetic Determinants of White Matter Hyperintensities on Brain Scans

Background and Purpose— White matter hyperintensities (WMH) are highly heritable and associated with small artery ischemic stroke, so they may be a useful trait for studying the genetics of small vessel disease. Many studies have attempted to find associations between polymorphisms in various candidate genes and WMH. We aimed to evaluate the evidence for these associations by performing a systematic review and series of meta-analyses. Methods— We used a comprehensive search strategy to identify studies of the association between any genetic polymorphism and WMH. For all polymorphisms in genes studied in >2000 subjects we performed meta-analyses, calculating pooled odds ratios or standardized mean differences. Results— We identified 46 studies of polymorphisms in 19 genes in ≈19 000 subjects. Most genes were involved in lipid metabolism, control of vascular tone, or blood pressure regulation. Polymorphisms in the apolipoprotein E, angiotensin-converting enzyme, methylenetetrahydrofolate reductase, and angi...