Genetic analysis identified copy number variations (CNVs) in the APP, PSEN1, PSEN2, MAPT, and GRN genes, while viral infections (HSV-1, HSV-2, CMV, EBV, HIV, SARS-CoV-2, Hepatitis A, B, and C) and vitamin D, B12, and B9 deficiencies were measured. This evidence concerns the gene APP and viral infectious disease.