Risk Gene

• The risk gene for Alzheimer's increases the likelihood that the disease will develop later in life, but the gene doesn't guarantee that the disease will develop. Genetic testing helps a person to determine if the risk gene is present.
  
  

Apolipoprotein E-e4 (APOE-e4)

• Apolipoprotein E-e4, or APOE-e4, is the Alzheimer's disease risk gene. The APOE gene can appear in three forms, including APOE-e2, and APOE-e3. APOE helps doctors understand one of the proteins that allows cholesterol to travel in the bloodstream.
  
  

Deterministic Genes

• If a person inherits deterministic genes for Alzheimer's, he will develop the disease. Scientists have found that deterministic genes are prevalent in only a few hundred extended families worldwide, according to the Alzheimer's Association's website.
  
  

Healthy Aging

• If a person has the risk gene for Alzheimer's, making choices that will help to delay the aging process can reduce the chances of developing Alzheimer's. Staying away from tobacco and alcohol can be very helpful, as can adopting a regular exercise program.
  
  

Head Injury

• According to the Alzheimer's Association, studies show a link between head injuries and development of Alzheimer's disease. Wearing a seat belt when in a car and wearing a helmet when riding a bicycle or motorcycle can decrease a person's likelihood of developing the disease.