Genetic test for androgenetic alopecia
Bologna, Italy — A novel genetic testing technique allows for patients who experience hair loss of any severity to know whether their condition is likely due to androgenetic alopecia. The genetic testing method, known as HairDx, is not used for diagnosis; instead, it is used to predict the risk of developing hair loss in patients at a young age, and, according to one expert, it can prove to be extremely useful in the clinical setting when treating and managing patients stricken with androgenetic alopecia.
Male and female pattern hair loss, or androgenetic alopecia, is the most common type of hair loss and can be a source of great psychological stress for the patient. It is thought that up to 50 percent of females will develop this condition over their lifetime, with up to 80 percent of males being affected, depending on their age. Patients who experience excessive hair loss can take this novel test to see whether they have a genetic predisposition for developing androgenetic alopecia.
“A negative test will surely placate those unfortunate individuals who experience hair loss, as the treatment of androgenetic alopecia can be challenging,” says Antonella Tosti, M.D., professor, department of dermatology, University of Bologna, Bologna, Italy. “However, a positive test will make patients take their therapeutic regimens more seriously and increase their compliance to treatment.”
The genetic sample is collected using a cheek swab. All cells have an androgen receptor, and the test works by assessing whether there is a polymorphism in the androgen receptor gene. If a polymorphism is found, the test is positive, indicating a 70 percent risk of the individual developing androgenetic alopecia at a young age. Though it is not 100 percent, the probability of developing androgenetic alopecia with a positive test is very high.
“If the polymorphism is not found, it does not rule out that a patient may develop androgenetic alopecia in the future. However, a negative test is even more specific than a positive result of the test, as a negative test indicates that the chances of developing androgenetic alopecia are very low,” Dr. Tosti says.
The HairDx genetic test is currently available on the market in the United States to physicians. It must be performed in an office setting. In Europe, the test is available to the general public.
Currently, the only therapies for androgenetic alopecia approved by the Food and Drug Administration include oral finasteride (Propecia, Merck) and topical minoxidil (Rogaine, McNeil-PPC) for men, and topical minoxidil for women. According to Dr. Tosti, both of these approaches work well. It is thought that topical minoxidil works by opening the potassium channels in the cells and thereby increasing the duration of the anagen growth phase of the follicle.
“I think that this genetic test is very useful for doctors, because we often have patients who are very distressed because of their hair loss, and therefore the testing may give them an opportunity to start the treatment earlier or simply serve to placate them, should the test be negative,” Dr. Tosti says. “If treatment with Propecia or minoxidil is started earlier, the final hair regrowth result is undoubtedly better, as all of the current literature indicates.”
Finasteride for women
To date, finasteride is indicated for use only by men. However, results of a recent six-month pilot study of HairDX in post-menopausal women suffering from androgenetic alopecia have shown that this therapy could soon also be used by women.
Researchers have found genetic evidence that can help identify females who could equally benefit from finasteride treatment. The study findings indicate that females with post-menopausal androgenetic alopecia have a female corollary to the androgenetic alopecia in men, opening the door for a new treatment for women with this type of hair loss.
On average, the therapeutic benefits of oral finasteride can be seen after approximately six months of treatment. The sooner the test is done, the sooner the patient knows his or her risk.
Response to finasteride
Dr. Tosti says that HairDx is developing a genetic test that may predict whether a patient will respond to oral finasteride. This new test will facilitate and clarify treatment options for patients with androgenetic alopecia.
“When a patient complains of hair loss, physicians should not be so quick to blame it on stress. It is always very important to rule out androgenetic alopecia, even in younger patients, and to have a definitive diagnosis,” Dr. Tosti says.
Disclosures: Dr. Tosti is an adviser for HairDx, but she reports no financial compensation from the company.
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