CD33 and dementia: The CR1 (rs3818361), BIN1 (rs744373), CD2AP (rs9349407), EPHA1 (rs11767557), CLU (rs1532278), MS4A6A/4A (rs610932), ABCA7 (rs3764650) and CD33 (rs3865444) SNPs showed no significant association with dementia in our cohort of individuals with DS, either singly or as part of a genetic risk score.