259-314 DNA Sci Chap 08

WE STAND AT THE THRESHOLD OF A NEW CENTURY with the whole human genome stretched out before us. It is, at once, a public and intensely private record. Written in each person’s DNA is a shared history of the evolution of our species and a personal portent of both the health and disabilities we may encounter as individuals. High-throughput analyses using bioinformatic tools and DNA arrays are uncovering an exponentially increasing number of genes implicated in human diseases. Each gene identified in a known disease pathway automatically becomes a validated target for therapeutic development. Pharmaceutical companies are racing to convert this new knowledge into blockbuster drugs while the medical profession ponders how it will keep up with the flood of new diagnostic and treatment options. The implications extend far beyond medicine, as scientists seek genes behind the behaviors—and misbehaviors—that make us uniquely human. The border between science fact and fiction will blur as we move further into the genome age. A tenfold increase in the information capacity of photolithographic DNA arrays could condense the entire human genome onto a chip the size of a postage stamp. Perhaps not everyone will be able to afford to carry a complete copy of their genome in a medical alert locket, but rapid scans of hundreds of medically and behaviorally important genes will almost certainly become part of standard medical care in developed countries. What will it be like when we have a precise catalog of all the good, bad, and middling genes—and the wherewithal to determine who has which? On a personal level, will a genome-wide scan take on the aspect of genetic tarot, predicting the future course of our lives? In the face of such knowledge, will society continue to acquiesce to those who prefer to let nature take its course or will we gravitate toward a prescribed definition of the “right” genetic stuff? This is not the first time that we have asked such questions. At the turn of the last century, science and society faced a similar rush to understand and exploit human genes. Eugenics was the name of the effort to apply principles of Mendelian genetics to improve the human species. The eugenics movement began benignly in England with positive efforts by families to improve their own heredity. It took a negative turn in the United States, as well as in Scandinavia, where flawed data became the basis for laws to sterilize individuals and restrict immigration by ethnic groups deemed “unfit.” These misguided attempts at eugenic social engineering formed part of the basis