Even as information technology has been driving striking social transformations over the past decade, a new form of information with similar transformative potential has also been coming online: the kind encoded in the DNA sequence of the human genome. Beginning on page 46 of this issue, John I. Nurnberger, Jr., and Laura Jean Bierut describe how the power of genetic analysis is even beginning to reveal the interactions of genes, environment and personal choice that make a person more or less vulnerable to a disorder as complex as alcohol addiction. Their investigations are based on data collected in a massive ongoing national study of alcoholics and their families, all of whom were willing to provide both DNA and detailed personal accounts to help researchers gain insights into this devastating illness.

Those kinds of volunteers are crucial to the study of how genes work, but fear could make them increasingly hard to find. The National Human Genome Research Institute reports that already about a third of the people approached to participate in genetic studies decline, worried that discovery of a genetic predisposition to illness could later subject them to discrimination from insurance companies or employers. Genetic counselors say that a large proportion of people tested for inherited disease risk factors hide that fact from their insurers for the same reasons.

At press time, the Genetic Information Nondiscrimination Act (GINA), which would bar prejudicial treatment based solely on gene data, was appearing to finally have enough momentum to become law. This bill has been bogged down in the House of Representatives twice in recent years, despite unanimous passage by the Senate both times and support from the White House. Opposition has come largely from business interests, which deride GINA as feel-good legislation that duplicates protections already offered by states and existing federal antidiscrimination laws such as the Americans with Disabilities Act (ADA).

If healthy people with a higher genetic risk for diabetes, for example, could be said to already have the disease, they might well be covered by the ADA. But with rare exceptions, genetic predispositions are no guarantee of illness, and the medical promise of genetic screening is to identify vulnerabilities before sickness arises so as to enable informed choices about risky behaviors, preventive monitoring and medication. If explicit federal protections make people feel better about participating in the genetic information age, it is therefore worthwhile to spell them out.

Passage of GINA will not end controversy over the proper uses of personal genetic data. Increasing access to genetic screening will surely influence debates over universal health care and medical records privacy. Beyond medicine, DNA is contributing to studies of human evolution, the creation of family genealogies, the identification of criminals and the exoneration of the wrongly convicted. Our society is already beginning to enjoy the fruits of this new form of information. But scurrilous entrepreneurs are also, predictably, beginning to offer unreliable DNA tests or bogus interpretations of the data, and more such abuses can be expected. As with other forms of personal information, over which we are willing to trade some measure of control for benefits, such as fast-track passes through airport security, genetic information will offer powerful rewards and some risks. Like any double-edged sword it should be handled carefully.