Direct-to-Consumer Genetic Testing

 JASON CHENG

test tubesG, A, T, C: these four letters comprise the language of DNA, and each represents a piece of the genetic code that makes us who we are. Until recently, we have been unable to read this genetic language; but our newfound literacy comes with dangerous side effects that must be controlled through strict regulation.

The Human Genome Project was the Rosetta Stone of a Golden Age of Genomics. Over 3 billion nucleotides of the human genome were sequenced, opening up new avenues of scientific understanding. Its applications are wide-ranging: already multiple genes have been linked to diseases that can be detected through genetic screening.

Diagnostic genetic screening has traditionally been confined to professional laboratories. A new breed of personalized, direct-to-consumer (DTC) genetic tests seeks to democratize these genomic analyses. But DTC genetic testing, while exciting, is not yet ready for the mass-market given its limitations and the social and moral issues it raises.

These products collect biological samples that are then analyzed using SNP genotyping, which looks for single nucleotide polymorphisms (SNPs) in sections of DNA. Essentially, the test identifies variations in individual nucleotides of DNA, which are then correlated to traits. 23andMe, a popular DTC genetics company, offers a report that includes “earwax type,” among other health metrics. The problem with SNP genotyping is that, by definition, it does not take into account the entirety of the genome or environmental factors and fails to capture complex interplays among coding sequences, promoter regions, and other mechanisms not fully understood. Additionally, the results are often given as percentages of likelihood—a seemingly empirical measurement that belies its uncertainty. For example, to test for breast cancer, point mutations in the BRCA1 and BRCA2 genes are analyzed. While mutations in these genes are correlated with a higher likelihood for breast cancer, having a mutation in these genes does not mean that an individual will have breast cancer nor does not having a mutation mean that an individual will not have cancer.

But DTC genetic testing, while exciting, is not yet ready for the mass-market given its limitations and the social and moral issues it raises.

Compounding this problem are the social and moral consequences of unregulated access to and marketing of genetic testing.

Traditional testing done in a professional environment is carefully presented in an informed and supportive manner often accompanied by a thought-out plan of action. Many hospitals have in-house genetic counselors and physicians. At-home testing lacks this support structure, which can potentially lead to mental distress and rash courses of action.

Beyond their inherent uncertainty, these tests also raise important moral concerns. With the ease of such testing and its adoption, how are we as a society prepared for this information? A bleak, dystopian future is portrayed in the movie, Gattaca, in which society is divided between those who are “genetically superior” based on genetic tests and those who are not. This have and have-not dilemma is further exacerbated by the recent intrusion of DTC testing into the realm of childbirth: 23andMe acquired a patent in October for “gamete donor selection”,  allowing prospective parents to choose what traits they desire in their children. Suddenly, Gattaca doesn’t seem too far-fetched.

In light of these problems, DTC testing must be strictly regulated. Already, at a state level, 13 states categorically prohibit it and 12 states restrict the marketing of certain categories of tests. Federal regulation must extend beyond U.S. Food and Drug Administration (FDA) evaluation, which ensures that they work as claimed, to the often blatantly manipulative manner in which these tests are advertised to consumers. A Hastings Center case study identified an advertisement targeted at women containing the following:

“If you could discover your risk for a second breast cancer or for ovarian cancer, would you?… Knowing your family history is neither enough, nor is it always accurate. This test is.”

These advertisements prey on the fears of consumers while also they mislead the public in a bid to get purchases.

Both the FDA and the Federal Trade Commission need to work together to ensure that DTC genetic tests being sold work and that the advertising of these tests to consumers is accurate and non-manipulative. Comprehensive genetic counseling options and disclaimers about their accuracy should also accompany these tests. Additionally, genetic privacy and non-discrimination needs to be safeguarded with a more stringent application of HIPAA privacy rules that extends to these test providers. Finally, embryonic genetic testing for reasons other than disease screening should be prohibited.

DNA was first isolated in 1869; nearly a hundred years later Watson and Crick identified its famous double-helix structure; another 50 years elapsed before the human genome was sequenced; only 5 years later, the first direct-to-consumer tests were available. Clearly, the rate of genetic technology and its accessibility is accelerating exponentially. This knowledge is a useful tool in disease screening, prevention, and treatment; but DTC tests must become more accurate in their analyses and be more stringently regulated.

Update, 12/1/13:  On November 25th, the FDA issued a warning letter to 23andMe, claiming that that they do not have any assurance that the firm has analytically or clinically validated its technology.”  The FDA may take legal action against 23andMe.

Jason Cheng is a Brevia staff writer.  He can be reached at jasoncheng@college.harvard.edu.