APOE and Huntington disease: Examples of hereditary genes and their corresponding disease are: HTT gene in HD, amyloid precursor protein (APP), presenilin (PSEN1, PSEN2), apolipoprotein E (APOE) genes in AD, chromosome 9 open reading frame 72 (C9org72), SOD1, and TAR DNA binding protein (TARDBP) genes in ALS (Pihlstrom et al., 2017).