However we found that the APOE4 allele frequency in these families is significantly higher compared to sporadic AD cases (72.13% vs. 60%, p = 2.18×10−6, OR = 1.71, 95%CI: 1.36–2.17) and controls (72.13% vs. 26%, p = 5.28×10−85; OR = 7.37, 95%CI: 5.86–9.27)(APOE4 frequencies obtained from Alzgene). The gene discussed is APOE; the disease is Alzheimer disease.