I discussed the general topic of individual DNA testing in an earlier post. There is an important twist that I cover here. Low-cost consumer-oriented genetic testing is making personal genomic information available to individuals in a way not intermediated by the medical or any other professional establishment. The result is an unprecedented opportunity for individuals to take more responsibility for their wellbeing and longevity. However, there are certain associated problems and hazards.
Up until recently, genetic testing was available through laboratories that mainly service professionals – medical people, crime specialists and genetic counselors for example. If you had a genetic test it was ordered for you with a specific purpose in mind by somebody who also interpreted the results. Now there are a number of direct-to-consumer web-based genetic testing services. A person goes on a website, orders a test, receives a kit and sends a sample in. He or she gets the result with no professional involved. At that point the person may or may not research the meaning of what was discovered further, may or may not decide to act on the results, and may or may not decide to consult a professional. The person may or may not share the result with his or her primary physician or spouse.
I have mentioned that a number of consumer companies do single-purpose tests, such as paternity testing or testing for HIV. There is a growing number of companies that simultaneously scan for a number of possible disease or other susceptibilities.
A much-discussed low-cost example example company is 23andme. For $399 the company sends you a kit. You spit into a tube and send it back to the 23andme lab and in 6-8 weeks the results are posted to a secure online site. The test looks at genes related to 114 disease conditions and traits, a list that grows in time. Examples of the conditions tested for include Parkinson’s Disease, Prostate Cancer, Psoriasis, Resistance to HIV/AIDS, Rheumatoid Arthritis, Sickle Cell Anemia & Malaria Resistance, Type 1 Diabetes and Type 2 Diabetes. For each condition tested, certain basic information is provided. The results provide an estimate of whether the genetic risk for a given condition is higher or lower than average, and background information on the condition and a list of counselors, links and condition-related support groups in the customer’s area. The results for any given condition are based on one or several genetic markers, six of them in the case of rheumatoid arthritis. Specific examples can be seen by clicking on any of the links just listed. The service is an example of genotyping (looking at SNPs, sequence variations within a single nucleotide) to determine certain genetic variants a person possesses, which is very different than sequencing an individual’s entire genome. 23andme also offers updated clinical reports and research reports on the diseases, traits and conditions covered.
Navigenics (www.navigenics.com) is another company in the consumer genomics game. It offers two levels of testing, one for $499 and its most comprehensive service for $2,499. Both services suggest individual’s genetic predisposition to the common health conditions covered and “information and support to help you prevent, detect or diagnose them early,” including limited access to genetic counseling. Decodeme is another company in the consumer-oriented testing game offering a “cardiovascular” scan for $199 and charging $985 for its “complete scan” which scans over a million genetic variations for 38 conditions. GeneDX is one of several specialized companies that scans for rare hereditary diseases. The most comprehensive service seems to be Knome which offers complete genome sequencing looking at all 3 billion base pairs in the human genome. “Each individual is assigned a complete team of bioinformaticians, geneticists and clinicians to conduct a comprehensive analysis of your complete genome.” The services are customized. Costs are unpublished but I would guess they could range up to $100,000.
Heralding the emergence of consumer genomic testing as a highly competitive industry, a trade show for the industry is scheduled, The Consumer Genetics Show, Boston, Hynes Convention Center: June 9 – 11, 2009.
The hope of widespread consumer genetic screening is that individuals can identify disease susceptibilities and take appropriate actions. If a person knows he has a susceptibility to cardiovascular disease or diabetes or he or she may make dietary and lifestyle changes to reduce the probability of the disease emerging. People with susceptibility to arthritis may elect to take additional anti-inflammatory supplements, for example. The individual is empowered to exercise preventative medicine on a personal level, clearly an important factor for enhancing longevity. Further, if a couple does such testing before having children, they could possibly spot common negative inheritable traits that could emerge in an offspring.
Some genetic counselors are dubious about massive consumer genetic testing. Reasons are 1. The state of research knowledge linking genetic markers to specific diseases is still very primitive and sketchy. For the disease susceptibilities that are multigenic (involving multiple genes), in most cases the causative gene relationships are yet to be identified. Scientific and medical researchers and practitioners have not agreed on appropriate diagnostic genetic biomarkers for most such conditions. Further some important known biomarkers are proprietary and patented and can only be used by the company owning the rights to use them. It is unclear who has the best biomarkers. 2. Individuals are apt to misinterpret genetic results, either missing clues or suffering unnecessarily from worrying about a disease susceptibility that will never be realized. For many of the conditions tested there is insufficient research evidence to justify firm conclusions. Results need to be interpreted along with other important information including family history, health history, current health, environment, lifestyle, etc. Providing such context and guidance to action is the role of genetic counselors. I have heard one such counselor say the 23andme tests “only have entertainment value and it would be dangerous to read anything else into them.”
In all fairness, all of the consumer genetic testing services provide optional or built-in linkages to genetic counselors and attempt to identify the reliability of their findings in terms of the current state of research. They also strive to keep up with such research and adjust their tests accordingly. I expect that as time progresses we will have better and better underlying research to back up test result conclusions and that genomic consumer testing will become more and more commonplace. Competition and lower-cost technology is likely to cause the tests to become ever cheaper, more comprehensive and cost-effective. The cost of gene testing is rapidly dropping according to a variant of Moore’s Law. (See the post on this Blog about the factors that drive Giuliano’s Law). The latest generation of microfluidic gene-analysis chips are little bigger than a flake of dandruff and are getting down to costing less than a bottle of shampoo. From $10, 000 down to $399 for a set of tests was a big drop. The next drop may be down to $69.99. And who knows if any bottom is in sight after that.
There is a message here to medical and health professionals: you better get out there and learn about the gene tests and what they can mean if you want to maintain your creditability with your patients. The same is true for longevity research, by the way.