A Genetic Defect May Increase the Risk of Alzheimer’s Disease
A new study suggests that Alzheimer’s disease may be significantly linked to heredity, providing a clearer picture of the gene long known to be associated with common forms of dementia.
The authors of the study, published in the journal Nature Medicine, argue that data from a large sample of over 500 individuals carrying two copies of the APOE4 gene variant showed biological features of Alzheimer’s disease. This led researchers to assert that possessing two copies of this gene should now be classified as a causative factor, rather than just an attribute.
Dr. Juan Fortea, co-author of the study, emphasized the broad impact of this conceptual shift, noting that approximately 15 to 20% of Alzheimer’s cases could be attributable to genetic causes.
Individuals with two copies of APOE4, known as APOE4 homozygotes, represent a small portion of the general population but constitute a significant proportion of Alzheimer’s patients. The study highlights that these individuals not only face an increased risk but also exhibit a rapid onset of cognitive decline, typically occurring before those without genetic predisposition.
The study underscores the need to explore new therapeutic approaches specifically tailored to this distinct genetic subtype, stating that while traditional treatments targeting amyloid plaques have dominated the landscape, it advocates for a reassessment of therapeutic approaches and calls for interventions addressing the unique genetic basis of APOE4 homozygotes.
Dr. Samuel Gandy, an Alzheimer’s researcher at Mount Sinai in New York, emphasizes the need for comprehensive clinical trials and advocates for the inclusion of APOE4 homozygotes in younger age groups to mitigate progressive diseases.
He notes that the study’s findings reignite the debate over genetic testing and counseling, prompting discussions about the ethical and practical implications of disclosing APOE4 status in asymptomatic individuals.
