DNA Days are here: navigating genomic tests in primary care
GPs are trusted sources of information about genome sequencing and are the profession most likely to be approached by people with results from online and consumer DNA tests. Read on to learn more about the important role GPs can play when it comes to navigating genomic tests in primary care.
As genetic and genomic tests become more accessible, medical practitioners including GPs are requesting more of these tests1 and receiving more test results. GPs have important roles to play in this type of testing including identifying and referring patients, providing information on genetics and genomics to patients, and clinical management and continuity of care for patients before, during and after testing.2,3
In 2018, the Australian Government committed investment of $500 million over 10 years in an Australian Genomics Health Futures Mission. Throughout this Mission, hundreds of thousands of people will participate in genomic research and clinical trials, and many will receive information that could affect their healthcare.4 GPs may encounter genomic test results or correspondence about patients participating in research and trials or may be involved in recruiting patients for genomic studies, such as the recently-launched Mackenzie’s Mission, the Australian Reproductive Carrier Screening Project.5
However, not all genomic tests have the same reliability, validity or utility.6,7 Australian consumers are also becoming more aware of, and are accessing DNA tests online,8 or through health, diet, and fitness pathways that may include integrative GPs, allied health professionals and complementary and alternative practitioners.9 These online DNA tests or personal genomic tests (also known as direct-to-consumer tests or consumer genomic tests) are marketed directly to consumers and may claim to provide patients with genetic information about ancestry, paternity, sporting ability and health.10
GPs are trusted sources of information about genome sequencing and are the profession most likely to be approached by people with results from online and consumer DNA tests.
Patients’ motivations to have these tests include: curiosity about DNA data; interest in specific disease risks based on personal symptoms or family history of a condition; or information seeking by people who are chronically ill or undiagnosed11. The majority of online DNA tests do not have clinical support, and are genotyping tests that utilise data from genome-wide association studies (GWAS). GWAS studies focus on identifying genomic variants associated with disease risk, rather than disease causation. The clinical utility of these variants continues to be studied in a research setting as they are less well understood 7.
There are very few personal genomic tests that consumers can access directly that will report variants that place an individual at significantly increased risk of a condition13. For example, an online DNA test rarely reports that a patient carries a pathogenic BRCA1 variant. If a patient received such information from a consumer genomic test it is recommended to refer the patient to a clinical genetic service or genetic specialist for testing to confirm the genetic finding and make recommendations for ongoing management13. Confirming the variant is important because a recent study found that up to 40% of online DNA test results were false positives that could not be confirmed in a clinical laboratory6.
GPs are trusted sources of information about genome sequencing12 and are the profession most likely to be approached by people with results from online and consumer DNA tests. 9 Patients may visit their GP with questions about testing, to request a test or referral, or arrive with their raw data or a report that includes a suite of risk results relating to hereditary conditions, metabolic issues, medication metabolism, fitness or nutrition.
GP can have a key role in advising patients of issues raised by online DNA tests, and in managing patients who have already received results. The RACGP has recently released point-of-care resource on Genomics in general practice with a section on personal genomic tests.13 The resource provides background, practice points and considerations, and highlights key roles for GPs, including advising patients of issues raised by online DNA tests and in managing patients who have already received results. The recent Genioz study, funded by the Australian Research Council, has also developed some evidence-based resources for community members who may be thinking of buying an online DNA test.14 For GPs who would like to learn more about genomic testing in the clinical setting, the Garvan Institute of Medical Research and ThinkGP recently launched an e-learning module and expert video. These resources aim to help GPs understand genomic tests and reports, and support their patients.
Variant: an alteration in our DNA sequence. Some changes can cause diseases – these are known as pathogenic variants.
Genetic testing: usually involves requesting a pathology test on a single gene, or a small number of genes.
Genomic testing involves a large number of genes, or even on an entire genome, with all the testing being performed in one investigation, and all (or nearly all) results being available in a single pathology report.
- White, V., Higginson, M., Nickerson, S., & Ravine, A. (2019). Australian Health Genetics/Genomics Survey 2017: The Royal College of Pathologists of Australasia. Retrieved from https://www.rcpa.edu.au/getattachment/2c045802-5284-4ff3-a0e4-749abc059e...
- The Department of Health (2018). National Health and Medical Industry Growth Plan – Australian Genomics Health Futures Mission. Retrieved from http://www.health.gov.au/internet/budget/publishing.nsf/Content/budget20...
- The Royal College of General Practitioners. Genetics in Primary Care. Retrieved from http://www.rcgp.org.uk/training-exams/gp-curriculum-overview/online-curr...
- Blashki, G., Metcalfe, S., & Emery, J. (2014). Genetics in general practice. Australian Family Physician, 43(7). Retrieved from https://www.racgp.org.au/afp/2014/july/genetics-in-general-practice/
- Australian Genomics Health Alliance (2018). Mackenzie’s Mission. Retrieved from https://www.australiangenomics.org.au/our-research/mackenzies-mission/
- Tandy-Connor, S., Guiltinan, J., Krempely, K., LaDuca, H., Reineke, P., Gutierrez, S., . . . Tippin Davis, B. (2018). False-positive results released by direct-to-consumer genetic tests highlight the importance of clinical confirmation testing for appropriate patient care. Genetics in Medicine, 20(12), 1515-1521. doi: 10.1038/gim.2018.38
- Torkamani, A., Wineinger, N. E., & Topol, E. J. (2018). The personal and clinical utility of polygenic risk scores. Nat Rev Genet, 19(9), 581-590. doi: 10.1038/s41576-018-0018-x
- Savard, J., Hickerton, C., Tytherleigh, R., Terrill, B., Turbitt, E., Newson, A. J., . . . Metcalfe, S. A. (2019). Australians’ views and experience of personal genomic testing: survey findings from the Genioz study. European Journal of Human Genetics. doi: 10.1038/s41431-018-0325-x
- Metcalfe, S. A., Hickerton, C., Savard, J., Stackpoole, E., Tytherleigh, R., Tutty, E., . . . Gaff, C. (2018). Australians’ perspectives on support around use of personal genomic testing: Findings from the Genioz study. European Journal of Medical Genetics. doi: https://doi.org/10.1016/j.ejmg.2018.11.002
- Human Genetics Society of Australasia (2018). Position Statement: Online DNA Testing. Retrieved from https://www.hgsa.org.au/documents/item/18
- Schmidt, J. L., Maas, R., & Altmeyer, S. R. (2019). Genetic counseling for consumer-driven whole exome and whole genome sequencing: A commentary on early experiences. Journal of Genetic Counseling, 28(2), 449-455. doi: 10.1002/jgc4.1109
- Genetic Alliance Australia (2016). Australian Patients’ and Families’ Perspectives on Genome Sequencing: Report and Patient Charter. Retrieved from http://www.geneticalliance.org.au/cmsAdmin/uploads/genetic-alliance-geno...
- The Royal Australian College of General Practitioners. Genomics in general practice. East Melbourne, Vic: RACGP, 2018.
- Genioz Study (Genomics: National Insights of Australians). (2019). Community resources. Retrieved from https://www.genioz.net.au/page/community-resources/
Ms Bronwyn Terrill
BSc, GradDipSciComm, DipEd GradCertAppSci, MEd
Bronwyn is a genomics educator and communicator in the Kinghorn Centre for Clinical Genomics at the Garvan Institute of Medical Research. She collaborates on research exploring the needs of Australia's health workforce in genomic medicine, what makes someone ‘genetically literate’, and public expectations of personal genomic testing.