Reacción a "Reactions: Spanish researchers propose new genetic form of Alzheimer's disease"

This report provides new, strong data showing that inheritance of two copies of the APOE4 gene is a cause of Alzheimer’s disease. The results force a change in thinking of APOE4 simply as a risk factor for Alzheimer’s.  As 2 of 100 Northern Europeans carry two copies of the gene, the authors highlight that this discovery makes APOE4 Alzheimer’s Disease one of the most common of all Mendelian genetic disorders. 

One implication of this work is that testing for APOE4 gene homozygosity should be assessed for use clinically when late middle-aged people present to their doctors with symptoms of dementia.  Because APOE4 homozygotes are common in the population, have predictable ages of onset and rates of progression of disease and, as demonstrated in the paper, show easy to measure biomarker changes as their disease evolves, they also constitute an attractive population for clinical trials of new treatments for Alzheimer’s disease.