The HairDX test — is it useful?

Wouldn’t it be great if we had a test that simply and reliably told you whether or not you had a genetic cause for your hair loss? If we did, then you could walk into a doctor’s office or lab and find an answer in no time at all. This would also benefit doctors as we wouldn’t have to rely on using our eyes and ears to get a good history and physical. There is a test that came out about 10 years ago to do just this called HairDX. It involved a simple swab taken from your cheek and its claim was that it could reliably tell if a patient was suffering from androgenetic hair loss and thus tell the patient if he or she would benefit from hair loss medications like minoxidil and finasteride.

It is still used by some doctors today but unfortunately, this test is not as accurate as we first hoped. In fact, HairDX might only be about 70% accurate. That’s a large number of cases that are incorrectly classified.

Why does HairDX give the wrong answer?

The likely reason is that HairDX only tests for one gene involved in genetic hair loss and we now know there are at least 250 genes involved in hair loss. It is therefore no surprise that a single gene test like HairDX is frequently incorrect. It just does not cover enough bases.

Although you can pay for this test at some doctor’s office, you should only do so if you can accept that the diagnosis you are given is very possibly incorrect because it does not test for the majority of the genes involved in hair loss. For this reason, Dr. Nakatsui does not currently offer HairDX to his patients. It incorrectly diagnoses too many patients and Dr. Nakatsui cannot reconcile charging patients for a test that is too often wrong. To date, the best method for correctly diagnosing genetic hair loss is to have an experienced physician evaluate you clinically and do a good history and physical examination to make the diagnosis and rule out other causes of hair loss.

The exciting thing is that now that we know more of the genes involved in genetic hair loss, we can one day come up with a better test. Hopefully, that day will come soon.

References:

Hagenaars SP et al. Genetic prediction of male pattern baldness. PLoS Genet. 2017 Feb 14;13(2)

The study looked at over 52,000 men. The researchers were able to identify 287 different gene loci that were linked to varying degrees of baldness.