Apolipoprotein E (APOE)

Apolipoprotein E (APOE) is a protein involved in the metabolism of fats in the body. It is implicated in Alzheimer’s disease and cardiovascular disease. APOE belongs to a family of fat-binding proteins called apolipoproteins. APOE interacts significantly with the low-density lipoprotein receptor (LDLR), which is essential for the normal processing (catabolism) of triglyceride-rich lipoproteins.

In peripheral tissues, APOE is primarily produced by the liver and macrophages, and mediates cholesterol metabolism. In the central nervous system, APOE is mainly produced by astrocytes and transports cholesterol to neurons via APOE receptors, which are members of the low density lipoprotein receptor gene family. APOE is the principal cholesterol carrier in the brain.

The ApoE gene provides instructions for making a protein called apolipoprotein E. In the brain, ApoE is involved in clearing harmful plaques that form around nerve cells.  These plaques are a hallmark of Alzheimer’s disease and consist of damaged proteins called amyloid β which stick together to form the toxic plaques.

There are at least three slightly different versions (alleles) of the ApoE gene. The major alleles are called E2, E3, and E4. The most common allele is E3, which is found in more than half of the general population.  The E2 form is the most effective at removing Aβ plaque from the brain and subsequently is protective against Alzheimer’s disease. However, the E4 form of the ApoE protein is not very effective at removing Aβ plaque and carries an increased risk for developing Alzheimer’s disease.

ApoE combines with fats (lipids) in the body to form molecules called lipoproteins. Lipoproteins are responsible for packaging cholesterol and other fats and carrying them through the bloodstream. Maintaining normal levels of cholesterol is essential for the prevention of disorders that affect the heart and blood vessels (cardiovascular diseases), including heart attack and stroke.  The ApoE test report includes results and comments related to both Cardiovascular and Alzheimer’s disease risk.

Ideal Candidates Have The Following Symptoms Or Conditions:

• Family history of dementia
• Symptoms of memory loss
• Pattern of decreasing intellectual ability
• Reduction in language and speech skills not related to other conditions

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