As this century draws to a close, spectacular advances in the fields of genomics and genetics are opening up dramatic new horizons for medicine. For much of the 20th century, genetic research has focused on rare diseases caused by mutations in a particular gene.
However, more recently it has been realised that common genetic variations (polymorphism), interacting with the environment, can influence an individual's susceptibility to diseases widely represented in our populations (e.g. mental illness and asthma), redefining the term 'genetic disease'. Officially starting in 1990, the Human Genome Project was a $3-billion, 15-year program to find the estimated 80,000 human genes and determine the sequence of the 3 billion DNA building blocks that underlie all of human biology and its diversity. The resulting boom in genetic information and technologies, not only from humans, but from many other organisms, means that we now have new tools to understand and treat normal and disease states. This information is being used by academic researchers, and increasingly by pharmaceutical companies, to identify genes for genetic diseases, susceptibility to disease, to understand the ways different individuals react to different medications and create new drugs and therapies. Largely misunderstood, 'cloning' is an attempt to use animals as 'bioreactors' to produce therapeutic biological molecules such as blood clotting factors or organs for transplants. As with all 'revolutions', the use of these technologies raises unprecedented questions of an ethical and legal nature. However, as we enter the new millennium, we can expect this biotechnology revolution to exert fundamental changes in the practice of medicine, affecting prevention, diagnosis, and therapy for important public health problems.
