APOE and early-onset autosomal dominant Alzheimer disease: Studies have found that APOE gene polymorphisms are closely associated with coronary heart disease, hyperlipidemia, cerebral infarction, Alzheimer’s disease, multiple sclerosis, chronic hepatitis, and other diseases (Ghiselli et al., 1981; Corder et al., 1993; Faivre et al., 2005; Price et al., 2006; Rovin et al., 2007; Kathiresan et al., 2008).