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"This is exciting because it's the first lab test for hair loss," said Alan Bauman, MD, hair restoration physician.
People hand over a saliva swab. It's taken back to the lab where the DNA is analyzed. Researchers look for a genetic variation on the X chromosome that's linked to hair loss.
"There's something psychological about having your hair. It's not totally getting old," said Tom Mastanduono, who has hair loss.
Low-risk means you have an 80 percent chance of holding onto your hair by age 60. High risk means there's a 60 percent chance of severe hair loss by 40.
Tom's 15-year-old son, Eric, is up next.
"I can see here that I'm high risk," said Eric. "It's a bit shocking to find out at such a young age."
One-hundred-million Americans have hair loss -- about 60 million are men and 40 million are women.
Doctors say the gene test puts the power of prevention in the patient's hands.
"This just gives another piece of information and then you decide with your doctor what you want to do," said Dr. Bauman, MD.
Tom's low risk, but will keep getting hair preservation therapy. And high-risk Eric won't seek preventive treatment ... yet.
"I don't really care, like, right now," said Eric. "It's not of that much importance, because I have a full head of hair and it doesn't really matter that much."
But he admits his opinions on his appearance may change in the future.