Is APOE ε4 required for Alzheimer's disease to develop in TREM2 p.R47H variant carriers?

Murray and colleagues [1] reported the occurrence of pathologically-confirmed Alzheimer's disease (AD) in cases harbouring the TREM2 p.R47H variant only when APOE e4 alleles were also present. They suggested that the presence of an e4 APOE allele is necessary for the development of AD pathology in TREM2 p.R47H carriers. This is an important hypothesis as it can have significant impact on individual risk assessment and on understanding the mechanisms of disease. This article is protected by copyright. All rights reserved.