Despite actor Chris Hemsworth’s widely publicized experience with genetic testing for Alzheimer’s disease, fans and followers of the “Thor: Love and Thunder” star may want to think twice before following his lead to get tested. While filming his new Disney+ series, “Limitless,” the 39-year-old learned he has multiple genetic links from both parents predisposing him to Alzheimer’s disease.
Health experts warn that genetic testing for Alzheimer’s may not be ideal for driving medical decisions and life plans. Therefore, adults should carefully consider the decision and weigh their health status, family history, desired outcomes, and motives before moving forward with genetic testing.
Alzheimer’s disease is the most common cause of dementia and affects memory, thinking, and behavior.
Who is an ideal candidate for genetic testing?
“Those with a strong family (genetic) history of Alzheimer’s disease may consider getting tested as early as their 20s to allow them to plan for the future should they possess ‘deterministic genes.’ However, it’s important to note that environment and lifestyle may have as great or greater impact than genetic propensity regarding the onset of Alzheimer’s disease,” said Sandi Petersen, MD, a gerontologist and senior vice president of Health and Wellness at Pegasus Senior Living.
“Only a small percentage of Alzheimer’s cases (less than 1%) are caused by specific mutations in one of three ‘deterministic genes.’ Deterministic genes mean that inheriting one of the genes virtually guarantees that an individual will develop Alzheimer’s disease,” Petersen said. “In such individuals, cognitive deterioration may begin in the 30 and 40s, while the vast majority of individuals with Alzheimer’s ‘risk genes’ may develop what is termed ‘late-onset disease,’ with disease onset at age 65 or older; however, there is no guarantee with ‘risk genes’ that an individual will develop the disease.”
With limited treatment options available for Alzheimer’s disease, most clinicians do not generally recommend routine testing, Dr. Petersen said. However, for those with a prevalent family history of Alzheimer’s, genetic counseling may be helpful.
“Genetic counselors are a worthwhile investment for those contemplating whether to get tested or not. These individuals can be helpful not only in the decision of testing or not testing, but also in life care planning for insurance, long-term care insurance, future care, and finances” for those with the greatest risk, Petersen said. She added that those with concerns about a family history of Alzheimer’s may want to discuss the need for genetic testing with their primary care provider.
Over-the-counter, direct-to-consumer home tests are available. However, Petersen advises against this option, as genetic self-test at-home kits are relatively useless without the professional genetic counseling required to accurately decipher the results, assess risk, and guide future plans.
How to prepare for the results if you decide to get tested
Susan Hahn, MS, CGC, board-certified genetics counselor and Director of Health Economics and Outcomes Research and Payer Relations at Quest Diagnostics, would recommend genetic testing for Alzheimer’s only to people who are experiencing symptoms of cognitive impairment.
She offered these important preparation tips for anyone who does decide to move forward with genetic testing:
- Obtain genetic counseling to fully understand what the test can achieve and the things to consider before choosing to take it.
- Appreciate that once the information is known, it cannot be unlearned; you can’t put the toothpaste back in the tube.
- Consider the impact of information on the ability to get life and long-term care insurance. The Genetic Information Nondiscrimination Act does not offer protection for these types of insurance.
- Consider the impact of the results on relatives. We inherit genes from our parents and pass genes onto our children. Results will impact them. For example, those who are found to have inherited two copies of the APOE4 variant now know that each parent and each of their children have at least one. Do these relatives want to know this information? How will this information impact them?
- Obtain clarity on why the information is desired and what will be done with it and weigh this value against drawbacks, such as the stress of knowing the information, impact on relatives, insurance concerns, etc. Genetic counselors can help patients navigate the pros and cons of testing, understand their risk, and interpret genetic testing results. They are also trained to help patients adapt to and understand the information.
Will there ever be a cure for Alzheimer’s disease?
Currently, there is no cure for Alzheimer’s. Therefore, learning that you are genetically predisposed to the disease could be an overwhelming experience. Genetics is only one factor of many in determining a person’s risk of Alzheimer’s. Health experts advise taking care of your health to minimize the risk of the disease. Taking control of your health and lifestyle choices could more positively affect future health outcomes than genetic testing.
“Brain health is closely linked to heart and blood vessel health in recent research,” Petersen said. “The risk of developing dementia appears to increase as a result of many conditions that damage the heart or arteries. These include high blood pressure, heart disease, stroke, diabetes, and high cholesterol. Building on this knowledge, recent studies are examining how best to strategize.”
“For example, current drugs for heart disease risk factors have led researchers to consider whether medications such as those to treat heart and vascular disease may also be beneficial for people with Alzheimer’s or may reduce the risk of developing dementia,” Petersen added.
Despite the lack of a cure, researchers say there are some promising potential Alzheimer’s treatments and preventatives among the hundreds of pharmaceuticals currently in clinical studies.
The Alzheimer’s Association provides an overview of a few of the most promising pharmaceutical, non-drug, and behavioral treatments available for people with Alzheimer’s disease, as well as ways people can optimize their health for the prevention of Alzheimer’s disease.
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