Alzheimer’s disease (AD) is a dementia caused by a chronic progressive degenerative disease of the central nervous system. It is the most common cause of dementia and the most common dementia in the elderly. AD is characterized by neuropsychiatric symptoms such as progressive memory impairment, cognitive dysfunction, personality changes, and language disorders. It often develops in the elderly or pre-elderly, and often develops slowly and gradually progresses, with dementia as the main manifestation. It develops before or after the elderly, and often has a family history of the same disease and the disease progresses rapidly. Genetic quality and gene mutation 10% of AD patients have a clear family history, especially those who develop the disease before the age of 65, so family history is an important risk factor. Some people believe that about 50% of first-degree relatives of AD develop the disease when they are 80 to 90 years old, and the risk is 2 to 4 times that of AD without a family history. Early-onset autosomal dominant abnormal AD is relatively rare. Currently, only 120 families in the world carry confirmed pathogenic genes. The genes related to the onset of FAD include chromosomes 21, 14, 1 and 19. So far, it has been found that FAD is an autosomal dominant genetic disease with genetic heterogeneity.