In announcing on June 26, 2000, that the first draft of the human genome had been achieved, President Clinton said it would “revolutionize the diagnosis, prevention and treatment of most, if not all, human diseases.”But it has been a decade since the first complete genomes were sequences, and so far the usable medicine to come out of this is minimal. The original idea was that we would identify the gene variants responsible for cancer, heart disease, diabetes, and so on. But the genetic background to these diseases has proved to be diabolically complex, depending on interactions between dozens or hundreds of genes. There are genetic tests for vulnerability to some diseases, such as breast cancer, but so far they work no better than the old method of studying family histories. A few treatments based on genetic information, but none are proven successes. Some people have thrown up their hands and walked away, like the new head of the National Cancer Institute, who once said "Genomics is a way to do science, not medicine." There are still enthusiasts, but they have lengthened the time frame of their predictions, and now they talk of great achievements fifteen or twenty years from now.
I think it will take at least that long and maybe longer. So far our knowledge of the genome itself remains limited, and our understanding of how changes in DNA are reflected in cellular processes barely exists. We need to know a lot more about how a genetic changes effects a protein and how the changed protein effects the operation of the cell before we will be able to use this information to fight disease. That knowledge will come, but only very slowly.