Can you trust a direct-to-consumer genetic test?
There are currently many genetic tests offered directly to consumers, ranging from relatively simple tests of ancestry to much more complicated predictions of disease risk and drug responses. In an industry as complex as this one, it can be difficult for consumers to decide which companies they can trust.
In the course of writing about the genetic testing industry I’ve taken tests from four different companies, with a fairly wide range of quality, and made my data publicly available. My background in genetics makes it easier for me to make sense of some of the results, but you certainly don’t need to have a PhD to separate the science from the snake oil. Here are a few useful rules of thumb that you can follow both before and after purchasing a test.
Do some background reading
Apply the same common sense approach you would for any major purchasing decision: Google the name of the company and look for positive and negative reviews. Keep an eye out for reports from consumer watchdog agencies, or blog posts by experts who are critical of the company’s accuracy. Don’t believe every critical review you read, but if there’s an overall picture of negativity, look elsewhere.
Check the company’s website
As an initial filter, look at the company’s website for the signs of dodginess you’d expect from any fly-by-night online scam. Poor grammar and web design, dubious customer testimonials, and offers to sell you nutritional supplements based on your genetic data are all strong predictors of shoddy genetic tests.
A legitimate company should provide you with a demonstration account illustrating the type of information you would receive as a customer, giving enough context for you to understand the results, as well as extensive links to other resources. Lists of the actual genetic variants tested should be easily available, along with clear references to the original research papers supporting the company’s claims.
It’s your genome
Check to make sure the company allows you to download your raw genotype data after the test has been done. It’s your genome, and you have a right to get access to this information. In addition, having access to the raw data will make it easier for you to double-check the company’s accuracy and interpretation. If a company doesn’t provide an easy way to download your raw data, find another provider.
Engage with your data
After purchasing a test, make sure you actively explore your results: dig deep, read as much as you can, and ask questions about anything that doesn’t make sense to you. There are plenty of online forums devoted to personal genomics and genetic ancestry and genealogy. Of course, like any online forum, you shouldn’t believe everything you read!
Right now the data provided by personal genomics companies isn’t profoundly useful from a health perspective for most of us, so should treat this process first and foremost as a learning experience. You’ll learn the most if you approach your own genome with a skeptical eye, searching for inconsistencies and surprising results and then tracking down their origins. This process may also alert you to errors in your data or its interpretation, as journalist Peter Aldhous has illustrated.
If alarmed, consult an expert
If you find something you think is truly worrying, follow up with an independent expert (a doctor or genetic counselor for health-related matters) to have the results confirmed and put in context before making any life-changing decisions. Direct-to-consumer tests aren’t clinical tests (and aren’t labeled as such); you should treat them as providing you with information, not definitive answers, and certainly not diagnoses.
However, be aware that most doctors are ill-prepared to deal with the types of complex information provided by a genome scan, so make the process as easy for them as possible. Most reputable companies will provide a simplified print-out of results you can present to a clinician.
Daniel MacArthur is a research geneticist at Massachusetts General Hospital. He writes about genetic testing at Genomes Unzipped