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Apolipoprotein E-4 Genetic (DNA) Test - Topic Overview

Most people who develop Alzheimer's disease do not have a history of the disease in their families. But if you do have a family history of Alzheimer's disease (one or more members of a family have had the disease), then your risk of getting it is higher. When a disease is found in families, the cause could be genetic (heredity), something in the environment, lifestyle choices, or a combination of these things.

A blood test can look for a substance that seems to increase a person's risk for Alzheimer's disease. The gene is called apolipoprotein E-4 (ApoE-4). The presence of ApoE-4 cannot predict for sure whether a person will develop Alzheimer's disease. Many people who have the ApoE-4 gene do not get Alzheimer's disease, and many people who do not have the gene still develop the disease. Most experts do not consider ApoE-4 testing a necessary or useful part of evaluating a person with suspected Alzheimer's disease.

Recommended Related to Alzheimer's

Dealing With Alzheimer's Disease Memory Loss

For John MacInnes, the beginnings of Alzheimer’s disease were startling. The retired executive and former pastor in Bloomfield Hills, Mich., first realized something was wrong as he was delivering a PowerPoint presentation to a community group. “Then in mid-sentence, I had problems,” he says. “I had a well-rehearsed script in front of me, but I couldn’t get the words right, couldn’t get them out. That kind of shook me up.” Memory loss and impaired thinking are hallmark symptoms of this disease...

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Early-onset Alzheimer's

Sometimes people develop Alzheimer's disease at a young age, between the ages of 30 and 60. This is referred to as early-onset Alzheimer's disease or autosomal dominant Alzheimer's disease. It is not common (less than 5 out of 100 cases), and this form of the disease has been linked to defects in specific genes. There is a 50% risk that these genes will be passed on. A person who inherits the genetic defect will most likely develop Alzheimer's disease.

    WebMD Medical Reference from Healthwise

    Last Updated: October 29, 2012
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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