ApoE genotype has been observed to be implicated as a risk factor in several neurological disorders such as Alzheimer’s Disease, Creutzfeldt-Jacob disease, Wilson’s disease, Multiple Sclerosis, cerebral amyloid angiopathy, Parkinson’s Disease and Lewy Body Dementia [105,106,107,108,109,110,111,112,113]. The gene discussed is APOE; the disease is Parkinson disease.