Neurologists from multiple institutions in Spain and the United States have studied brain data from thousands of deceased Alzheimer's patients, as well as biomarkers from over 10000 living patients. The results indicate that approximately 15% to 20% of Alzheimer's disease cases may be attributed to carrying two copies of the APOE4 gene. The relevant paper was published in the new issue of the journal Nature Medicine. Alzheimer's disease is generally divided into two types: one is early-onset, caused by mutations in genes such as apps; Another type is late onset, which has multiple genetic risk factors, and APOE4 is considered one of the risk factors. In the latest study, scientists analyzed pathological data from 3297 deceased Alzheimer's disease patients, as well as data from an additional 10039 living Alzheimer's disease patients collected from multiple medical institutions. They found that almost all patients carrying dual copies of the APOE4 gene exhibited some form of pathological features of Alzheimer's disease, such as abnormal levels of amyloid protein in the cerebrospinal fluid at the age of 65 (which forms plaques in the brain and is a hallmark of Alzheimer's disease). Researchers suggest that individuals carrying dual copies of the APOE4 gene typically experience symptoms 10 years earlier than other forms of Alzheimer's disease patients. The research results indicate that individuals with two copies of the APOE4 gene account for approximately 15% to 20% of Alzheimer's disease patients. These cases should be regarded as a unique type that requires personalized prevention strategies, clinical trials, and therapies. (Lai Xin She)