Concerning Alzheimer disease (AD), currently ApoE testing is used in clinical settings to identify people who may have an increased risk of developing AD, whereas other genetic tests investigate the presence of autosomal dominant mutations (in genes PSEN1, PSEN2, and APP which are more predictive for disease development (Goldman et al., 2011). The gene discussed is APOE; the disease is early-onset autosomal dominant Alzheimer disease.