Ten years ago, Peter Collins and Craig Venter, leaders of the Human Genome Project announced they had completed the first draft of the human genes sequence. Published later in 2001 in Nature, the initial decoding of the human genome’s 3 billion base pairs – about 22,000 genes – was considered a major scientific breakthrough. The expectations on future developments were set high. “With this profound new knowledge, humankind is on the verge of gaining immense, new power to heal. It will revolutionize the diagnosis, prevention and treatment of most, if not all, human diseases,” said Bill Clinton, by then the United States President.
But, as a decade passed by, most of these promises remain unfulfilled. The reason for this is the extraordinary complexity of genes and gene expression. As it turned out, genetic sequences are not just a blueprint for an organism, as initially thought. From a genetic sequence, it is not possible to predict a structure or a behavior. Ultimately, the end result is greatly influenced by its regulatory mechanisms, which in turn are conditioned by the environment. All in all, organisms are not simply the expression of the genome, but they are the result of a myriad of interactions between the environment and the genes.
Today, a small number of procedures based on the human genome have entered routine medical practice: some gene-specific treatments for certain cancers, some novel therapies for very specific types of traits and some strong genetic markers for assessing drug responsiveness, risk of disease, or risk of disease progression.
The initial Human Genome Project gave rise to other ventures. The HapMap project compared the genomes of several hundred people to produce a map of genomic hotspots where people would likely to have DNA differences. It was followed by The 1000 Genomes Project, which aims the creation a detailed catalog of human genetic variation . The Encyclopedia of DNA Elements and the Roadmap Epigenomics Program will continue to identify the locations of genes and the patterns that determine whether genes are switched on or off, defining the ‘parts list’ of the human genome. Scientists hope these projects will help to understand the mechanisms behind common diseases leading to personalized medicine.
Both leaders of the Human Genome Project remain positive about the impact of genomics in healthcare and medicine. “The promise of a revolution in human health remains quite real,” wrote Collins, in the special issue of Nature dedicated to 10th anniversary of the human genome announcement. “The genome revolution is only just beginning”, concluded Venter, who recently announced the creation of the first synthetic cell.
Sources: Nature 2010; 464 (7289): 649 – 804 , The Lancet 2010; 375:2194, The New England Journal of Medicine 2010 362:2028-2029, Suite101.