Pharmacogenetic testing through the direct-to-consumer genetic testing company 23andMe

Abstract

BackgroundRapid advances in scientific research have led to an increase in public awareness of genetic testing and pharmacogenetics. Direct-to-consumer (DTC) genetic testing companies, such as 23andMe, allow consumers to access their genetic information directly through an online service without the involvement of healthcare professionals. Here, we evaluate the clinical relevance of pharmacogenetic tests reported by 23andMe in their UK tests.Methods The research papers listed under each 23andMe report were evaluated, extracting information on effect size, sample size and ethnicity. A wider literature search was performed to provide a fuller assessment of the pharmacogenetic test and variants were matched to FDA recommendations. Additional evidence from CPIC guidelines, PharmGKB, and Dutch Pharmacogenetics Working Group was reviewed to determine current clinical practice. The value of the tests across ethnic groups was determined, including information on linkage disequilibrium between the tested SNP and causal pharmacogenetic variant, where relevant. Results23andMe offers 12 pharmacogenetic tests to their UK customers, some of which are in standard clinical practice, and others which are less widely applied. The clinical validity and clinical utility varies extensively between tests. The variants tested are likely to have different degrees of sensitivity due to different risk allele frequencies and linkage disequilibrium patterns across populations. The clinical relevance depends on the ethnicity of the individual and variability of pharmacogenetic markers. Further research is required to determine causal variants and provide more complete assessment of drug response and side effects.Conclusion23andMe reports provide some useful pharmacogenetics information, mirroring clinical tests that are in standard use. Other tests are unspecific, providing limited guidance and may not be useful for patients without professional interpretation. Nevertheless, DTC companies like 23andMe act as a powerful intermediate step to integrate pharmacogenetic testing into clinical practice.

Genetic Testing in Clinical Settings

“…Arguably, direct-to-consumer genotyping will act as a powerful conduit for integrating pharmacogenomics into practice as evidence for its clinical utility is being collected. 39 With the expansion of such testing, educational initiatives on direct-to-consumer genotyping are essential to improving the health literacy of healthcare providers and the public. 40…”

<p>Pharmacogenomic Testing In Pediatrics: Navigating The Ethical, Social, And Legal Challenges</p>

“…Many genetic tests, including PGx testing, are considered a ‘laboratory-developed test’ (LDT) and at this time, the FDA typically does not enforce premarket review179 and only a few test manufacturers or laboratories of proprietary tests have obtained FDA approval for PGx testing. In addition, the direct-to-consumer company 23andMe received FDA approval in 2018 to market a multi-gene PGx test panel,180 though this has been available in the UK 181. However, the agency is taking more interest in the clinical validity of PGx testing and potential risk for harm through issuance of safety alerts and warning letters to a clinical laboratory.…”

Integrating pharmacogenetic testing into primary care

“…While most likely unrelated to the clinical indication for sequencing, the test results may nonetheless inform treatment decisions. [37] Furthermore, direct-to-consumer testing may provide an opportunity for patients to order testing on their own [38] and share the test results with providers.…”

“…FDA began to send out notifications to several companies offering DTC testing, followed by warning letters, essentially halting the industry by requiring approval of testing services. [140] At least one company has obtained approval to offer DTC testing now, though DTC PGx testing is not approved at this time in the U.S. (though is available in the UK [38]).…”