Even though DS‐AD largely parallels the pathophysiological and clinical presentation of AD in the carriers of the autosomal dominant gene mutations in presenilin 1 (PSEN1), presenilin 2 (PSEN2), or APP, the diagnosis of dementia due to DS‐AD remains challenging, predominantly due to the heterogeneous presentation of clinical symptoms, widely varying level of baseline cognitive capacity and the lack of standardized tests to assess and evaluate these.8, 9. Here, PSEN1 is linked to Alzheimer disease.