San Diego: Dr John Kelsoe has spent his career trying to identify the biological roots of bipolar disorder. In December, he announced he had discovered several gene mutations closely tied to the disease, also known as manic depression. Then Kelsoe, a prominent psychiatric geneticist at the University of California, San Diego, did something provocative for the buttoned-down world of academic medical research: He began selling bipolar genetic tests straight to the public over the internet last month for $399. His company, La Jolla-based Psynomics, joins a legion of startups racing to exploit the boom in research connecting genetic variations to a host of health conditions. More than 1,000 at-home gene tests have burst onto the market in the past few years. The proliferation of these tests troubles many public health officials, medical ethicists and doctors. The tests receive almost no government oversight, even though many of them are being sold as tools for making serious medical decisions. Health experts worry that many of these products are built on thin data and are preying on individuals' deepest anxieties. "People are always rushing to the market on the basis of one or two studies,' said Dr Muin Khoury, director of the National Office of Public Health Genomics at the Centers for Disease Control and Prevention. Tests have become available claiming to help predict and diagnose everything from serious illnesses like cancer and Alzheimer's to athletic ability and a person's ideal diet. Psynomics' offering is one of the first psychiatric gene tests on the market. AP