About 15 minutes into my last haircut, the hairdresser stared at my reflection in the mirror and impassively mentioned my hair was thinning right above the temples. My heart skipped a beat. I was incredulous, mainly because my hair isn't thinning at all, though I do have a fairly pronounced widow's peak. Besides, this was the first time he had cut my hair, so how could he really tell? Still, like a magician, he seemed to conjure out of thin air a new product for sale that I could massage into my scalp to help regrow the phantom hair—or at least postpone the terminus of my youth. Thanks a lot.
But what if there was a way to find out if male pattern baldness—also known by its scarier medical appellation, androgenic alopecia—was in the cards in the years ahead? Would it really be worth knowing?
As it happens, there's now a commercial genetic test that purportedly can assess the risk of developing MPB before the age of 40. The test, called HairDX, looks at variations in the androgen receptor gene along the X chromosome, which men inherit from their mother, and it yields a percentage that's supposedly the risk of a particular man going bald. As home genetic tests go, it's pretty standard fare: Buy the kit (for $149), swab the inside of your mouth with a brush for about a minute, send it back in a return envelope, and about three or four weeks later, check the results on a confidential and secure Web page.
The thing is, the androgen receptor gene may not be the only factor that determines which of us go bald—or when. Numerous studies have linked the gene to baldness, and one found it to be the "major determinant" of MPB. This makes sense biologically, according to Paradi Mirmirani, a member of the faculty of the American Academy of Dermatology, because hair thinning begins after puberty when the androgen hormone surges through the male body. But scientists still know very little about the genetics and heredity of balding, especially whether just a single gene or multiple genes contribute to the trait. The growing consensus, says Mirmirani, is coming down on the side of multiple genes. So knowing whether you have a particular variant of the androgen receptor gene will evince only a piece of the total picture.
Similarly, knowing if your maternal grandfather went bald can be helpful, because your mother inherited one of her X chromosomes from him and may have passed on that chromosome to you. But again, it won't tell the whole story. In a 2001 study in the European Journal of Dermatology, researchers found that men who have a bald father have a higher risk of developing MPB than those who don't. Similar findings were presented in a 2004 Dermatology study. Those findings give credence to balding being a trait inherited from both sides of the family.
Dermatologists say they can often predict if a patient in, say, his late teens or mid-20s will go bald before 40 just by looking at his scalp, not at his DNA. Because pattern thinning is characterized by visibly fine, smaller-than-normal hair follicles, combining a close examination with family history can be a good predictor of MPB.
So what's the advantage of finding out early that you may have an increased likelihood of going bald? When the time comes, HairDX CEO Andy Goren says, a man might choose to seek prompt treatment. He says his company aims to provide men with the knowledge to decide on possible treatment options, including medication or surgery. (Goren says neither he nor his company has financial interests in the various treatments.) Indeed, early treatment of MPB with the two drugs approved by the Food and Drug Administration, minoxidil and finasteride, does seem to be more effective at halting or reversing hair loss than waiting until the later stages of the condition, says Mirmirani, who serves as a consultant for Pfizer, which produces Rogaine (minoxidil). Yet, she adds, a traditional diagnosis will give a patient information that a genetic test will not, such as the scope of thinning or whether thyroid disease or iron deficiency may be causing the balding.
Tests for baldness genes might someday be put to other uses, including predicting, and ultimately treating, major diseases. A few large studies have connected hair loss with diseases such as prostate cancer and heart disease. Some experts suspect the hormone dihydrotestosterone is the common link. It's noteworthy that finasteride, which blocks dihydrotestosterone production, is used (at different doses and under different brand names) to treat both MPB and prostate cancer. (For hair loss, it's sold as Propecia, and for prostate problems, Proscar.)
A look back at some old photographs confirmed that my hairline hasn't changed since I was very young. But although I don't plan on sending any spit swabs through the mail for testing, I do on occasion still catch myself glancing in the mirror just to make sure.