The Uncertain Future of Genetic Testing

<!-- /* Font Definitions */ @font-face {font-family:Cambria; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Cambria; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} a:link, span.MsoHyperlink {color:blue; text-decoration:underline; text-underline:single;} a:visited, span.MsoHyperlinkFollowed {mso-style-noshow:yes; color:purple; text-decoration:underline; text-underline:single;} span.authornames {mso-style-name:authornames;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Secti

In an opinion piece from authors at the Stanford Center for Law and the Biosciences, the future of genetic testing is discussed.

After a warning letter from the FDA, 23andMe had to halt their service that provided direct-to-consumer health interpretation of SNP chip results (though they still provide the raw data and ancestry information). Something “intended for use in the diagnosis of disease or other conditions or in the cure, mitigation, treatment, or prevention of disease” is regarded as a device by the FDA. 23andMe had marketed their Personal Genome Service product, which involved a spit kit, as “the first step in prevention” and “toward mitigating serious diseases” (see letter). However, it was not approved as a device, and as the company had failed to provide adequate information regarding analytical and clinical validity, the FDA required discontinuation of the product. Had the kit been ordered via a doctor from a lab that used the same tests, action may not have been taken.

One major problem is that no defined guidelines on the regulation for genetic testing are available; a kit by Illumina has been approved without the need to demonstrate clinical validity. The authors discuss how the FDA have continued to delay announcing a proposed policy for the regulation for genetic tests, reflecting the difficulty in determining the clinical validity of these tests (in particular for variants with weak effects or unknown significance). The interpretation of the effect of SNP risk alleles on health can vary markedly. Another concern of direct-to-consumer genetics is the interpretation of the results by the consumer and possible medical interventions they may subsequently undertake without medical expert advice.

An even more difficult scenario for establishing regulatory rules comes as the era of whole genome/exome sequencing technology takes over SNP chips. Regulation needs to be a fine balance between halting genetic testing altogether by requiring clinical validity for every single variant, and preventing “quacks” from selling their wares.

Read the opinion piece:
23andMe, the Food and Drug Administration, and the Future of Genetic Testing. Patricia J. Zettler, JD; Jacob S. Sherkow, JD; Henry T. Greely, JD. JAMA Intern Med. Published online February 17, 2014.

Subscribe to ClinPGx Blog

Don’t miss out on the latest issues. Sign up now to get access to the library of members-only issues.