“Through these data, we are saying that perhaps this is a genetic form of the disease, rather than just an indication of a risk factor,” study co-author Sterling Johnson of the University of Alzheimer’s Disease Research Center told reporters. Wisconsin, in the United States, at a meeting about the study.
Scientists have known for three decades that people with two copies of the APOE4 gene variant have a significantly higher risk of developing the disease than people with the more common version of the APOE gene, known as APOE3. About 2% to 3% of the general population, or about 15% of people with Alzheimer’s, have two copies of the APOE4 variant.
“This study adds compelling data to suggest that people with two copies of this gene are almost certain to develop Alzheimer’s if they live long enough, and that they will develop Alzheimer’s earlier than people without this gene,” said Professor Tara Spires-Jones, Alzheimer’s researcher at the University of Edinburgh, who was not involved in the study.
University of Barcelona researcher Juan Fortea and his peers studied more than 3,000 brains donated by the US National Alzheimer’s Coordinating Center, as well as biological and clinical data from more than 10,000 individuals from five datasets in three countries.
They found that by age 65, at least 95% of people with two copies of APOE4 — known as homozygotes — had abnormal levels of an Alzheimer’s-related protein called amyloid beta in their spinal fluid, and 75% had brain scans. positive for amyloid.
Almost all APOE4 homozygotes in the study had higher amyloid levels at age 65 than people who did not have the risk variant.
Tags: People copies risk gene genetic form Alzheimers scientists
