Pleiotropy analysis between lobar intracerebral hemorrhage and CSF β-amyloid highlights new and established associations.

Combining biologically related traits in genome-wide association studies (GWAS) increases the power for genetic discovery. Given the established relationship between lobar intracerebral hemorrhage (ICH) and cerebral amyloid angiopathy (CAA), and between the latter and levels of cerebrospinal fluid amyloid-β 42 (CSF-Aβ42), we leveraged genetic predisposition for lower CSF-Aβ42 levels as a proxy phenotype for CAA to identify new genes associated with lobar ICH.