"There's many different considerations…unless there's a compelling reason a person should know [such as research], then no, I would not recommend that people go out and get this test."
Caselli noted that a number of problems could arise from getting the test, in the forms of employer discrimination, insurance discrimination, and children who might learn of an increased risk to themselves.
"I argue that until we have the entire set of genetic risk factors for Alzheimer's…and look a them as a group, in the end you're cumulative risk involves hundreds, if not thousands of risk factors," said Tanzi, whose own research has focused on finding all of the genes connected with Alzheimer's.
He notes, however, that a study such as this could be easily misinterpreted.
"You don't want to risk that kind of discrimination when it's not really warranted. It's not warranted," Tanzi said. "Just because you carry an E4, you're not cognitively different from anyone else. Importantly, there's no correlation between ApoE4 and intellectual achievement.
"There is no effect on E4 as measure by your occupation or educational success or outcomes. It's just saying the disease is starting before you see symptoms, but it's pretty close to when the symptoms occur."
Caselli said one effect of this study is that it adds to the knowledge that Alzheimer's might affect the elderly, but does not begin then.
"The age group that we're talking about is pre-retirement," he said.
While people may typically think of Alzheimer's as an "old person's disease," he said, "actually, the earliest stages of it happen where we're still employed.
"It's important to keep in mind that this could start to have an effect on people in very intellectually demanding jobs as they age, as they try to remain employed."
Most research going on, Caselli said, is targeted at people who are much older. He believes that as we move towards experimental trials for prevention, "we really have to shift the spotlight to a younger age."
But while the disease might have its roots in that age group, he said, it does not generally have its symptoms then.
"I'm hoping that we don't generate a lot of panic in a lot of people in this age group," said Caselli.
"The dangerous way to look at it is to say people who carry E4 are cognitively deficient, even earlier in life," said Tanzi. "You don't want to invite discrimination when they're in the prime of their lives, when they're just fine."