NRGN and Alzheimer disease: Upon analyzing the relationship of synaptic-related biomarkers with the demographic and clinical features of AD patients, we found that both CSF Ng and α-Syn were positively correlated with the age of the patients at onset, and at the time of diagnosis, Ng correlated negatively with the MMSE, while Aβ 42/Ng and Aβ 42/α-Syn positively correlated with the MMSE.