APOE and early-onset autosomal dominant Alzheimer disease: In a paper from 2015, Nordestgaard et al. found that a loss-of-function mutation in ATP-binding cassette transporter A1 (ABCA1) was associated with a higher risk of Alzheimer’s disease, and also with plasma levels of HDL cholesterol, total cholesterol, apolipoprotein E, and apolipoprotein AI [61].