Among the seven FTD genes analyzed, we observed only one pathogenic variant in the microtubule-associated protein tau gene (MAPT, c.1537 C>G, p.P513A), which was discovered in a male patient (#2) who developed progressive slowing in memory with an onset age of 51 years, while no pathogenic mutation was found in APP, PSEN1, or PSEN2 genes. The gene discussed is APP; the disease is frontotemporal dementia.