Notably, Aß affects synapse loss in AD hippocampus by disruption of Ncam2 [22] and overexpression of wild-type PS1 or PS1 with a familial AD mutation (M146L) leads to decreased sialylation of Ncam in the neuroblastoma cell line SH-SY5Y [23]. This evidence concerns the gene NCAM1 and Alzheimer disease.