Furthermore, age; modifiable risk factors like obesity, physical activity, hypertension, depression, and diabetes; family history of dementia; and genetic factors like the carriage of the apolipoprotein E (APOE) ε4 allele have been associated with an elevated risk of overall dementia or Alzheimer’s disease (AD) [25, 26]. The gene discussed is APOE; the disease is obesity due to melanocortin 4 receptor deficiency.