What is genomic medicine?
Genomic medicine is a complicated topic, and mass media coverage—some well-documented and responsible, others unsubstantiated hype or nay-saying—has not brought clarity. So it seems like a good time to answer some of the most important questions about it.
What is genomic medicine and how does it differ from current medicine?
Our genomes—the complete collection of DNA found in our cells, all 3.2 billion or so base pairs—provide the foundation for our health. Genomic medicine is based on the premise that understanding how our genomes affect health and disease will allow for an individualized medical approach, leading to more precise, more personal care.
A good way to compare genomic medicine with current care, which is based on population averages, is to think of personal tailoring versus off-the-rack clothing. Imagine a clothing store that has only medium sized shirts, made to conform to a population average. Unless you’re lucky, your shirt won’t fit very well. And if you’re very large or very small, it may even be downright annoying or painful to wear. On the other hand, a tailor will use your individual measurements to make a shirt that fits you perfectly.
Current medicine is often “one-size-fits-all,” averages that work for many or most people but not for others, and some therapies may even harm a percentage of patients. Genomic medicine uses genome data to tailor treatment to the individual. The theory says that in time, the data will be used to discover the root cause of rare diseases, assess susceptibilities to certain health problems, find the most effective therapies, avoid ineffective or potentially harmful treatments and so on.
Has genomic medicine reached the clinic already?
In very focused, specific ways, the answer is yes. There have been several well-publicized success stories in which children with severe unknown diseases have had their treatments altered—and outcomes vastly improved—after sequencing found mutations in specific genes. A proof-of-concept study for practical use of whole genome sequencing in a neonatal intensive care unit showed that the speed and cost of the sequencing has progressed to the point that it can be a very valuable tool for identifying severe early-life disease.
For adults genomic medicine is particularly useful in oncology. A recent discovery in lung cancer patients, for example, identified a mutation target in a small percentage of patients for which there was already an approved drug available, and the early results are encouraging. Such testing can also reveal when a therapy won’t work, sparing the patient the sometimes-devastating side effects as well as saving time and money. More and more cancers are being characterized on a genetic and molecular basis, rather than solely by area of origin. Tumors are sequenced or at least assessed for certain genetic mutations, with the therapy guided by the results.
When will genomic medicine play a larger role in healthcare?
To put it bluntly, the medical system is not yet ready for large-scale implementation of genomic medicine. There are many players that need to come up to speed, including:
- The FDA: How should clinical genome technologies be regulated?
- Insurance companies: When should sequencing and genotyping be reimbursed?
- Doctors: Surveys show about 90% don’t know enough about genomics to confidently use the new technologies in their practice.
- Healthcare IT: How do you manage incorporating huge amounts of sequence data in health records?
- Privacy and ethical concerns
The time and money needed to sequence a genome have decreased so quickly that sequencing is on the way to becoming routine. On the other hand, analyzing the results and implementing findings in medical practice are still very difficult tasks.. The next few years will likely see a large-scale effort to incorporate genomics into clinical use, as costs continue to plunge and clinical usefulness increases. It will be interesting to see how the system responds.
Can genomes be used to predict future health?
One of the ballyhooed potential benefits of genomic medicine has been its theoretical predictive power. What can our genomes tell us about diseases that we will get or are particularly susceptible to? Yes, it can be clear-cut, as when a patient has the mutation for Huntington’s disease. But for the most part this has remained a problematic area, in large part because we don’t live in a vacuum.
Our genomes provide a foundation for our health, but our environments and behaviors also have significant impacts. For example, our genome may provide very low cancer susceptibilities, but if we live in a toxic environment, like next to a hidden chemical dump, we may well develop cancer nonetheless. Or a behavior such as smoking tobacco can tip the scales. My favorite statement on the subject is “genetics are probabilistic, not deterministic,” meaning that our futures are seldom hard-wired into our genes. As we gain greater understanding of our genomes we will learn far more about disease susceptibilities, but the predictive powers of genome sequences will still need to be assessed within a larger framework, especially in generally healthy people.
How will JAX Genomic Medicine contribute to genomic medicine?
There is a lot of work being done to advance genomic medicine, involving many of the leading minds in research and medicine. It’s therefore fair to ask why JAX Genomic Medicine, set to break ground in Farmington, Conn., is important and how it will contribute to the field.
The Jackson Laboratory has studied mammalian genetics for 83 years, using mice to model human disease. Its expertise in the field is formidable, and it has thousands of carefully characterized mouse strains useful for research. Combining its expertise and resources in disease model research with advanced genomics research capabilities and access to human patients will create a highly efficient and powerful genomic medicine research platform.
The goal of biomedical research has traditionally been characterized as “bench to bedside,” in which research discoveries are brought to patients. At JAX Genomic Medicine the flow will go both ways, including “bedside to bench to bedside,” in which human conditions and can be modeled directly and efficiently in mice and therapies tested. Genomic research capabilities will also make discoveries in mice more useful, as disease genes can be quickly identified in both humans and mice and mutation effects assessed in parallel.
The more we learn about genomics, the more we learn about how much we still don’t know. JAX Genomic Medicine offers a unique opportunity to expand—and test—our knowledge our own genomes while improving biomedical research and, in the end, clinical care.