The Research Institute of the Hospital de la Santa Creu i Sant Pau (IR Sant Pau) in Barcelona led a study that identified a new genetic form of Alzheimer’s disease, the duplication of the APOE4 gene. The research, published in the journal “Nature Medicine”, concludes that “virtually” all people who have two copies of the APOE4 gene (APOE4 homozygotes) develop signs of Alzheimer’s disease and proposes a reconceptualization of this genetic form, considered until now a risk factor. The study analyzed data from 3,297 brain donors, with samples from 273 APOE4 homozygotes from the US National Alzheimer’s Coordinating Center and more than 10,000 individuals, including 519 APOE4 homozygotes from five multicenter cohorts in Europe and the United States of subjects with Alzheimer’s biomarkers. The researchers observed that more than 95% of people over 65 who have the APOE4 gene duplication show biological features of Alzheimer’s in the brain or biomarkers of this disease in cerebrospinal fluid and PET.
“The data clearly show that having two copies of the APOE4 gene not only increases the risk, but also predicts the onset of Alzheimer’s disease.”
Based on these results, they stated that APOE4 homozygotes, instead of a risk factor, represent a genetically determined form of Alzheimer’s disease, which is why they suggest a reconceptualization of the disease similar to that proposed a few years ago in Down syndrome.
For decades, the scientific community has known that APOE4 is associated with an increased risk of developing Alzheimer’s, but until now it had not been established that it could be a determining cause of the disease. “We are talking about millions of people in Spain and many more millions in Europe and around the world, so we are facing an opportunity,” emphasized Juan Fortea, director of the Research Area in Neurological Diseases, Neuroscience and Mental Health of IR Sant Pau. He explained that, in fact, “the ultimate cause is in the genes” and emphasized the importance of this discovery because between 2% and 3% % of the population has this genetic variant, which accounts for 15% of Alzheimer’s cases.
Researcher Alberto Lleó stated that “the data clearly show that having two copies of the APOE4 gene not only increases the risk, but also anticipates the onset of Alzheimer’s disease, reinforcing the need for specific preventive strategies.”
Fortea added that the study found that there are populations with specific causes of Alzheimer’s disease and that understanding the causes of the disease and its subtypes allows “to move toward a future with more individualized therapies,” as has happened in oncology treatment./rcostea
(www.20minutos.es – May 8)
