With genetic scientific advances reported almost daily, it sometimes seems as if we are merely waiting for researchers to discover the gene at fault for every human disease. The complex genetic basis of many common diseases, however, complicates prediction, diagnosis and treatment.
The Wellcome Trust Case Control Consortium (WTCCC), a constellation of more than 50 British research groups, took on the mammoth challenge of ferreting out the causes of diseases in which multiple genes are implicated. Last June they reported the findings of a study that scanned for specific gene variations among 17,000 British citizens: 2,000 each from patient groups diagnosed with bipolar disorder, coronary heart disease, Crohn's disease, rheumatoid arthritis, hypertension and diabetes types 1 and 2, as well as 3,000 unafflicted who served as a control group. The large scale of the study was unprecedented and so was the payoff: 24 locations in the genome were found to be associated with six of the seven diseases.