The Human Genome Project was sold to the general public largely on the basis that a complete picture of the structure of human DNA would lead to new and better medicines. These medicines would be better because they would be tailored to individual patients, maximising the chances of a therapeutic response and mi- nimising the risks of an adverse event. Taking the idea further, pundits have pre- dicted that the time will come when we could carry our DNA on a card which could be read rapidly and enable the physician to choose the best drug. This is the future. This is pharmacogenetics. When the...