Established risk factors include genetic predispositions (e.g., APOE ε4 allele and Down syndrome)28, common medical conditions (e.g., diabetes, hypertension)29,30, neurodegenerative disorders, (e.g., Parkinson's disease, Lewy body dementia)31, and nutritional deficiencies (e.g., thiamine deficiency)32. The gene discussed is APOE; the disease is nutritional deficiency disease.