APOE (apolipoprotein E)

The APOE gene encodes the apolipoprotein E protein, which is a central component of the low density lipoprotein (LDL) particle in serum, a delivery vehicle for lipids Humans have three isoforms, apoE2,-3,-4, of which apoE 3 is the most prevalent. ApoE4 is a major genetic risk factor for atherosclerotic vascular disease and Alzheimer disease in most populations. While apoE4 is considered the ancestral isoform, the apoE of chimpanzees and other great apes differs at another amino acid, which is predicted to render apoE3-like functions. The much lower prevqalence of ischemic vascular disease and Alzheimer disease in captive chimpanzees may be related to these species differences in apoE. There are theories about how this diversification may have been related to the advent of increased meat-eating and the differential handling of cholesterol by the human species. No population based data are available for great ape apoE isoforms.