APP and Alzheimer disease: Two patients (patient 1 54-year-old male, patient 2 49-year-old female, see pedigree in Fig. 1a) with early-onset (at 20 years of age) familial AD carrying the APP D678H mutation and two healthy volunteers (control 1: 31-year-old male, control 2: 63-year-old female) assented to skin biopsies for derivation of iPSCs.