Dana G. Smith: Testing for Alzheimer's

The actor Chris Hemsworth announced last week that he’s taking a break from acting to focus on his health. The news came after Hemsworth learned through genetic testing that he has two copies of the APOE4 gene variant, which is associated with increased odds of developing Alzheimer’s disease, the most common form of dementia. The 39-year-old star of “Thor” has not reported having any symptoms, but he told Vanity Fair that he wanted to focus on mitigating his risk as much as possible.

Should you, like Hemsworth, undergo genetic testing to assess your risk for Alzheimer’s? And if you have the variant, what options are available to prevent or delay the condition? Here’s what to know.