MAPT and Alzheimer disease: Considering his early‐onset cognitive decline, despite his lack of a family history of dementia, we applied a targeted next‐generation sequencing panel for detecting possible mutations in candidate genes related to AD and FTD, including APP, PSEN1, PSEN2, MAPT, GRN, CHMP2B, TYROB, TREM2, PRNP, DCTN1, and NOTCH3, all with negative results.