HairDX Genetic Test

The HairDX Genetic Test is the first genetic test for early-onset male androgenetic alopecia (pattern baldness). Men who test positive are at a high risk of developing early-onset baldness. In contrast, men who test negative can be reassured that they are at a low risk of early-onset baldness. The objective of the HairDX screening test, is to identify Male Pattern Hair Loss prior to the onset of symptoms, allowing diagnosis in an earlier or preclinical stage, so that treatment can be initiated at a time when intervention has a greater likelihood of success.

The HairDX genetic test for Male Pattern Hair Loss provides information on the presence of a specific variation in the androgen receptor gene (AR), found on the X chromosome. The variant AR causes changes in the hair follicle's response to dihydrotestosterone, leading to alterations in the hair growth cycle. The variant AR is found in more than 95 percent of bald men 60 percent of men who have the variant AR will develop baldness by age 40. HairDX also provides information on a less common AR variant that predicts a very low risk of early-onset androgenetic alopecia. More than 85 percent of men who have this variant will not have hair loss by age 40. Men who test positive for the variant AR should be advised that they are at a high risk of developing early-onset Male Pattern Hair Loss. These men may wish to consult with a physician specializing in hair restoration, who can develop a plan to monitor and treat early hair loss. For example, such men may be good candidates for finasteride (Propecia), especially if treatment is started early. In contrast, men without the variant AR can be reassured that they are at low risk of early-onset Male Pattern Hair Loss. This avoids unnecessary concern or expense over premature hair loss.

Recent advances in human genetics empower researchers to discover the genetics of many common disorders. As genetic science is evolving in a rapid pace new discoveries are made almost daily.

The HairDX Genetic Test is committed to providing the latest in genetic discoveries to individuals. Although the causative genes for Androgenetic Alopecia (AGA) are not yet fully characterized, prevailing evidence supports a polygenic model based primarily on the fact that autosomal and single gene inheritance theories are not supported by observed patterns.

Evidence against an autosomal pattern are the observed phenotypic prevalence of AGA in families which does not fit the expected bimodal distribution. A single gene hypotheses would yield an expected prevalence of around 1:1000, far less than the high percentage of affected males seen in population studies .

Efforts to identify the causative genes have focused on those known to be related to mechanisms of hair growth. However, tests failed to reveal any association between the suspect genes and AGA, with one notable exception. There have been 4 published studies involving over 2900 patients which document the association between AGA and the androgen receptor (AR) gene on the X chromosome.

A particular polymorphism or variant allele at the AR site has been shown to be associated with a higher risk of developing AGA (>60%) and, conversely, a protective, less frequent allele which has been associated with a very low likelihood of developing AGA (>85% probability of not developing AGA)(1)(2)(3)(4).

The value of this test is that it offers the first credible, reproducible screen for assessing an increased risk for the development of AGA prior to the onset of symptoms. It also provides a means for patients with the A allele, and a strong family history of AGA to learn their risk of developing AGA is, nevertheless, small. Because of the limitations in specificity at this time a confirmation test should be used to determine the need for medical therapy. Confirmation tests include the "pull test", or one of the newer trichometric methods of assessing Anagen :Telogen ratio. A normal A:T ration is 12:1, as AGA progresses this drops to 5:1. Documentation of a falling A:T ratio indicates the onset of AGA. Although the sensitivity of the genetic screen is high, the specificity reduces the predictive value, so how is this test better than watchful waiting? First of all, studies have shown that men are reluctant to visit doctors unless they think that something is "wrong", (2007 Harris Interactive Online Survey for AAFP) and without visible thinning or some other warning, many won't seek medical therapy or advice. Furthermore, many patients shed very gradually, they do not see hair in the sink, on the pillow or on their clothes and thus may not notice hair loss is occurring, once again, until a pattern has developed. Allowing these patients an opportunity to become aware of their risk, can increase vigilance, allow them to learn about their options, and to seek more frequent medical assessment until medical intervention is warranted. Conversely, those patients who will suffer rapid shedding, may not do so in a gradual, stepwise pattern of shortened growth cycles, but rather a sudden change from anagen to telogen and then hair loss without gradual miniaturization. This group of patients will need intervention very quickly to intercede in the hair loss process, and in the absence of planning in advance, it is likely that delays in getting in to see their doctor and instituting therapy will result in unnecessary hair loss and perhaps alternate more expedient but perhaps less useful therapies in the meantime.

The continued success of many ineffective, unapproved treatments for hair loss suggests that many patients have not been educated by medical doctors regarding effective treatment options. A relatively inexpensive screening test, which is non invasive and easy to perform, and highly reproducible, can potentially attract patients to their doctor to seek expert advice. By adhering to ethical principles that dictate patients interests are paramount, other family members with hair loss may gain confidence and become willing to investigate their options. Furthermore, while it is true that some patients who initiate medical therapy may never develop significant hair loss or require future hair restoration surgery, there will be those who do not seek or stay on medical therapy despite their known risks. For example, consider the fact that cholesterol screening and lipid lowering medications while life saving for many, have not eliminated the need for coronary artery bypass surgery. Likewise, hair restoration surgery will continue, for now, to be the most effective therapy for replacing areas of bald scalp.

Male Pattern Hair Loss is an emotionally devastating condition. Unfortunately, 50% of men will experience some degree of hair loss by the age of 50. The most common form of hair loss in men (Androgenetic Alopecia also known as Male Pattern Hair Loss) occurs in men that are genetically predisposed. Figure 1 depicts the typical progression of Male Pattern Hair Loss. Like any medical condition, early detection is the best practice for prevention. Prior to the introduction of the HairDX Genetic Test, the prediction of Male Pattern Hair Loss remained a difficult challenge that was met with limited success. Because, the only FDA approved medications to combat hair loss, minoxidil and finasteride, are most effective at stabilizing hair loss rather then re-growth, the earlier you can predict Male Pattern Hair Loss, the more likely you are to save your hair. Proper early prediction and diagnosis of male hair loss is key to saving your hair.