In fact, 10–40% of MCI individuals with normal CSF Aβ42 may ultimately develop AD dementia [13–17], and CSF Aβ42, as well as the other core AD biomarkers total tau (t-tau) and phosphorylated tau (p-tau), have been associated with an increased risk of progression to AD dementia among memory clinic patients with normal levels of CSF Aβ42 [18]. The gene discussed is MAPT; the disease is Alzheimer disease.