What is Genomic Medicine?
What is genomic medicine?
NHGRI defines genomic medicine as “an emerging medical discipline that involves using genomic information about an individual as part of their clinical care (e.g., for diagnostic or therapeutic decision-making) and the health outcomes and policy implications of that clinical use.” Already, genomic medicine is making an impact in the fields of oncology, pharmacology, rare and undiagnosed diseases, and infectious disease.
The nation’s investment in the Human Genome Project (HGP) was grounded in the expectation that knowledge generated as a result of that extraordinary research effort would be used to advance our understanding of biology and disease and to improve health. In the years since the HGP’s completion there has been much excitement about the potential for so-called ‘personalized medicine’ to reach the clinic. More recently, a report from the National Academy of Sciences [dels.nas.edu] has called for the adoption of ‘precision medicine,’ where genomics, epigenomics, environmental exposure, and other data would be used to more accurately guide individual diagnosis[nimh.nih.gov]. Genomic medicine, as defined above, can be considered a subset of precision medicine.
The translation of new discoveries to use in patient care takes many years. Based on discoveries over the past five to ten years, genomic medicine is beginning to fuel new approaches in certain medical specialties. Oncology, in particular, is at the leading edge of incorporating genomics, as diagnostics for genetic and genomic markers are increasingly included in cancer screening, and to guide tailored treatment strategies.
How do we get there?
It has often been estimated that it takes, on average, 17 years to translate a novel research finding into routine clinical practice. This time lag is due to a combination of factors, including the need to validate research findings, the fact that clinical trials are complex and take time to conduct and then analyze, and because disseminating information and educating healthcare workers about a new advance is not an overnight process.
Once sufficient evidence has been generated to demonstrate a benefit to patients, or “clinical utility,” professional societies and clinical standards groups will use that evidence to determine whether to incorporate the new test into clinical practice guidelines. This determination will also factor in any potential ethical and legal issues, as well economic factors such as cost-benefit ratios.
The NHGRI Genomic Medicine Working Group (GMWG) has been gathering expert stakeholders in a series of genomic medicine meetings to discuss issues surrounding the adoption of genomic medicine. Particularly, the GMWG draws expertise from researchers at the cutting edge of this new medical toolset, with the aim of better informing future translational research at NHGRI. Additionally the working group provides guidance to the National Advisory Council on Human Genome Research (NACHGR) and NHGRI in other areas of genomic medicine implementation, such as outlining infrastructural needs for adoption of genomic medicine, identifying related efforts for future collaborations, and reviewing progress overall in genomic medicine implementation.
Examples of Genomic Medicine
- The causes of intellectual disability are often unknown, but a team in The Netherlands has used diagnostic exome sequencing of 100 affected individuals and their unaffected parents in order to uncover novel candidate genes and mutations that cause severe intellectual disability. NEJM, 2012. [PubMed]
- Colorectal cancers with a particular mutation can benefit from treatment with aspirin post-diagnosis. Aspirin (and other non-steroidal anti-inflammatory drugs) decrease the activity of a signaling pathway called PI3K. Between 15 and 20 percent of colorectal cancer patients have a mutation in a gene called PIK3CA that makes a protein that’s part of the PI3K pathway, and it has been discovered that regular aspirin treatment is associated with increased survival compared to colorectal cancer patients who have the non-mutated version of PIK3CA. NEJM, 2012. [PubMed]
- Currently, every baby born in the United States is tested at birth for between 29 and 50 severe, inherited, treatable genetic diseases through a public health program called newborn screening. Whole genome sequencing would enable clinicians to look for mutations across the entire genome simultaneously for a much larger number of diseases or conditions. Rapid whole genome sequencing has been shown to provide a useful differential diagnosis within 50 hours for children in the neonatal intensive care unit. Science, 2012. [PubMed]
- Researchers at Stanford University in California have been developing a new test to detect when a transplanted heart may be rejected by the recipient. Currently, the only way to detect the onset of rejection is by performing an invasive tissue biopsy. This novel approach only requires blood samples, and detects the levels of cell-free circulating DNA from the donor organ in the recipient’s blood stream. This circulating DNA from the donor can be elevated for up to five months before rejection can be detected by biopsy, and the level of DNA correlates with the severity of the rejection event (i.e., more circulating DNA signals a more severe event). Sci Transl Med, 2014. [PubMed]
- Cell-free circulating DNA is also being explored as a biomarker for cancers. As tumor cells die they release fragments of their mutated DNA into the bloodstream. Sequencing this DNA can give insights into the tumor and possible treatments, and even be used to monitor tumor progression (as an alternative to invasive biopsies). Sci Transl Med, 2014. [PubMed]
- Pharmacogenomics involves using an individual’s genome to determine whether or not a particular therapy, or dose of therapy, will be effective. Currently, more than 100 FDA-approved drugs [fda.gov] have pharmacogenomics information in their labels, in diverse fields such as analgesics, antivirals, cardiovascular drugs, and anti-cancer therapeutics.
- FDA has also cleared or approved [fda.gov] 45 human genetic tests, and more than 100 nucleic acid-based tests for microbial pathogens.
- DNA sequencing is being used to investigate infectious disease outbreaks, including Ebola virus, drug-resistant strains of Staphylococcus aureas and Klebsiella pneumoniae, as well as food poisoning following contamination with Escherichia coli. Sequencing has also recently been used to diagnose bacterial meningoencephalitis, rapidly identifying the correct therapeutic agent for the patient.
- Cystic fibrosis is one of the most common genetic diseases, caused by mutations in a gene called CTFR. More than 900 different CTFR mutations that cause cystic fibrosis have been identified to date. Approximately four percent of cases are caused by a mutation known as G551D, and now a drug called ivacaftor has been developed that is extraordinarily effective [nejm.org] at treating this disease in individuals with this particular mutation.
- Whole genome sequencing or whole exome sequencing (where only the protein-coding exons within genes, rather than the entire genome, are sequenced), has been used to help doctors diagnose-and in some extraordinary cases to identify available treatments-in rare disease cases. For example, Alexis and Noah Beery, a pair of Californian twins, were misdiagnosed with cerebral palsy, but DNA sequencing pointed to a new diagnosis, as well as a treatment, to which both children are responding well. Another patient who was misdiagnosed (for 30 years) with cerebral palsy was also found to have a treatable dopa-responsive dystonia thanks to whole exome sequencing. In another case, a young boy in Wisconsin, Nic Volker, was able to be cured of an extreme form of inflammatory bowel disease after his genome sequence revealed that a bone marrow transplant would likely be life-saving.
- The translation of new genomic medicine discoveries is already making a difference to patient care.
For more examples of genomic medicine advances, please see Notable Accomplishments in Genomic Medicine
NHGRI Genomic Medicine Activities
At NHGRI, the Division of Genomic Medicine administers research programs with a clinical focus. A number of research programs currently underway are generating the evidence base, and designing and testing the implementation of genome sequencing as part of an individual’s clinical care:
- The Electronic Medical Record and Genomics (eMERGE) Network is exploring the best way to integrate genomic variant information within electronic medical records (EMR). eMERGE is also studying the ethical, legal, and social issues involved in the use of EMRs for genomics research, such as privacy, confidentiality, and communications to the public, as well as the return of actionable genomic test results to EMRs for use in clinical care.
- The Clinical Sequencing Exploratory Research Program is exploring how best to integrate genome sequencing into clinical practice, currently with a focus in cancer and cardiovascular disease.
- NSIGHT, a joint program with the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) will be using genome sequencing to better the understanding of disorders that occur during the newborn period.
- The IGNITE Network includes new and ongoing successful genomic medicine projects that expand the implementation of genomic medicine. These demonstration projects incorporate genomic information into the electronic medical record and provide clinical decision support for implementation of appropriate interventions or clinical advice.
- The Clinical Genome Resource (ClinGen) aims to collect phenotypic and clinical information on variants across the genome, develop a consensus approach to identify clinically relevant genetic variants, and disseminate information about the variants to researchers and clinicians. This resource is essential for advancing the goals of implementing genomics in clinical care and will improve the understanding of phenotypic and functional effects of genetic variants and their clinical value.
NHGRI’s Division of Policy, Communications, and Education, is involved in helping pave the way for the widespread adoption of genomic medicine.
- PPAB has been working with payers (both private insurers and also the Centers for Medicare and Medicaid Services) on the issue of reimbursement for new genetic and genomic tests.
- PPAB has also been working with other federal agencies on the regulation of genomic tests, both in research and in clinical practice.
- DPCE has been involved in promoting genetic literacy among healthcare workers through electronic resources such as the Genetics and Genomics Competency Center [genomicseducation.net] and the Global Genetics and Genomics Community[genomicscases.net].
- My Family Health Portrait is the Web-based tool from NHGRI and the U.S. Surgeon General’s Family History Initiative that helps you document your own family health history. Using any computer, an Internet connection and an up-to-date Web browser, you provide your health information to build a drawing of your family tree and a chart of your family health history. Both the chart and the drawing can be printed and shared with your family members and your doctor. Risk assessment tools for diabetes and colon cancer are also available.
- The Inter-Society Coordinating Committee for Practitioner Education in Genomics (ISCC) facilitates interaction between NIH and professional medical societies to exchange practices and resources in clinical care. The ISCC identifies the needs of these professional societies in filling gaps in evidence and knowledge, offering partnership and available expertise to guide development of educational initiatives and applications for clinically relevant advances in genomic science.