Given the family history, further genetic analyses of the proband and his siblings affected by FTD and AD were performed, but no pathogenic mutations were identified in superoxide dismutase 1 (SOD1), GRN, MAPT/TAU (exons 9 to 13), synuclein alpha (SNCA), amyloid beta precursor protein (APP) (exons 16 to 17) and presenilin 1 (PSEN1) genes. Here, APP is linked to Alzheimer disease.