Introducing the Microbiome into Precision Medicine.
APRIL 14, 2013, MARKS THE 10TH ANNIVERSARY OF the completion of the Human Genome Project. Concurrently, the nation is in the process of reforming health care, with the aims of reducing costs, increasing access, and improving outcomes. One decade since the Human Genome Project’s end, the question remains, how has sequencing the human genome contributed to achieving these goals? When addressing this question it is important to remember that the Human Genome Project was not conceived with health care reform–related goals in mind. Rather it was an audacious scientific challenge that took advantage of the preeminence of the United States in life sciences to advance and accelerate knowledge of the fundamental biology of humans, as is necessary for the progress of medicine. An aspirational term 10 years ago, genomic medicine is practiced today in a wide variety of clinical scenarios by an increasing number of health care professionals. Cancer has been one of the more prolific areas of genomic medicine, with a steady growth in the availability of targeted therapeutics since the approval of trastuzumab for ERBB2positive breast cancer. This new treatment was followed by gefitinib for epidermal growth factor receptor activated non– small cell lung cancers. More recently, KRAS genotyping of colorectal cancers has been shown to predict response to cetuximab and panitumumab. In chronic myeloid leukemia, testing for the bcr-abl translocation prior to receiving imatinib is now the standard of care. In 2012, 2 cancer drugs received accelerated approval by the US Food and Drug Administration for use with a companion diagnostic: crizotinib for the treatment of ALK rearrangement-positive non– small cell lung cancers, and vemurafenib for metastatic melanomas that test positive for BRAF V600E mutations. These therapies have prolonged life and improved quality of life for many patients with these cancers. Patientswithotherdiseasesarealsobenefiting fromadvances ingenomicscience. In2012, the first therapeuticwasapproved forcystic fibrosis, ivacaftor, adrugthat targets theG551Dmutation of the CFTR gene in 4% of patients. Equally important contributions to patient management have been achieved in pharmacogenomic approaches to treating cardiovascular disease, infectious diseases, depression, and pain control. In addition to the health benefits of the Human Genome Project for society, genomic technologies are emerging as an important contributor to the global economy as evidenced by the thousands of biotechnology firms formed since the 1990s, the embrace of genome-enabled drug discovery by pharmaceutical industry, and the growth of the molecular diagnostics markets globally. High-quality, high-throughput genomics hubs have developed in the United States, Europe, China, South America, and Japan that serve both industry and health care systems around the globe. This year the World Economic Forum has taken up personalized and precision medicine as a priority area for development, emblematic of genomic science’s economic importance. Innovation has substantially reduced the cost of sequencing DNA such that next-generation sequencing technology can be used in certain clinical settings. Whole genome sequencing for the identification of genetic variations for rare mendelian disorders is now being applied in some settings at birth (newborn screening), in utero (prenatal diagnosis), or at the preconception stage (carrier testing). In 2011, clinical prenatal testing of trisomy 21 by sequencing of maternal plasma containing cell-free fetal DNA began in the United States and China. Sequencing advances have also contributed to increased awareness of the role of the microbiome in health and disease, and more facile approaches for detecting pathogens. Early results suggest that alterations in microbiota are both pathognomonic of disease and offer potential probiotic solutions for some conditions such as inflammatory bowel disease. Pathogen sequencing for diagnosis of infectious disease was recently used in real time to track and control an outbreak of methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit. While these examples reflect some of the triumphs of genomics in health care, the past decade has also brought some disappointment. Among the unmet expectations of genomics is the failure of genome-wide approaches to provide genetic risk information that is superior to traditional clinical risk models for complex disease susceptibility. Additionally, ambiguous regulatory approval and coverage