Deoxyribonucleic acid—DNA—is the genetic material found in all living cells. It determines hereditary traits such as eye or hair color, as well as a person's risk for developing genetically related diseases such as Down's syndrome or certain types of cancer. Because DNA differs in each person, a trained technician can identify an individual by examining the DNA in small samples of tissue or bodily fluids.
The unique properties of DNA have led people to study it in a variety of situations. Doctors can use DNA testing to find out whether an unborn child has certain genetic defects. DNA testing can also determine whether a person is at risk for developing some diseases later in life. Today, police can analyze DNA found at crime scenes in traces of blood, semen, skin, or hair to identify criminals. Although DNA testing provides valuable information, it also raises some troubling issues, especially with regard to privacy.
The broadening use of DNA testing has led to some basic questions about when testing is justified and who should have access to the results. These questions pit the individual's right to privacy against society's interest in maintaining public health and safety. They have surfaced most often in the areas of medical screening and criminal justice.
Medical Uses of DNA
The use of DNA to identify potential health problems has raised issues about access to such information. For example, health insurance companies have a strong financial interest in their clients' test results. Knowing whether an individual may develop heart disease or cancer later in life can help an insurer estimate the cost of a client's future medical treatment. Many people worry that insurers will refuse coverage to people whose tests indicate that they might develop diseases that require expensive treatments.
Some of the same concerns arise in the job market. Employers screening DNA tests could reject applicants who seemed likely to drive up their health care costs. A 1997 survey found that more than 6,000 employers in the United States used genetic testing to help them make employment decisions.
Debate also exists over the question of sharing an individual's DNA test results with family members. A person's relatives or children may carry similar genetic material and risk the same diseases. Some believe a doctor should share genetic information to promote health. However, doctors are legally bound to protect their patients' confidentiality. This obligation conflicts with any right a relative might claim to obtain information that may seriously affect his or her health.
The use of DNA testing before or during pregnancy involves different issues. Couples concerned about the possibility of genetic defects sometimes undergo screening before deciding to have a child. If the tests indicate a high risk of certain defects, the parents may choose not to have children. The use of DNA testing during pregnancy raises a more controversial matter—abortion. The discovery of possible defects may lead some parents to end the pregnancy rather than give birth to an unhealthy child.
Legal Uses of DNA
DNA testing has become one of the most powerful tools available to law enforcement agencies. Because DNA exists in every cell of the body, any physical traces left at a crime scene may identify those present when the crime took place. DNA samples can also help clear innocent people suspected of wrongdoing. DNA evidence has played an important role in several high-profile criminal cases, most notably the O.J. Simpson murder trial in the mid-1990s.
Today, all fifty states collect DNA information from convicted felons, and some states even take samples from those convicted of minor offenses. Together, these samples make up a database of previous offenders, which law enforcement agencies can check when working on unsolved crimes. However, the accuracy of DNA analysis has presented problems. Current techniques require testing of DNA from several areas of a DNA molecule and are subject to error. Even when testing is done accurately, confirming a match with a particular individual requires some interpretation by the tester. The defense attorneys in the Simpson case successfully questioned the accuracy of the DNA testing that linked their client to the crime scene.
The many groups that now collect DNA information include not only local law enforcement agencies but also the FBI, the military, and many hospitals and private employers. Civil liberties groups such as the American Civil Liberties Union (ACLU) question how these databases may be used in the future. They worry that DNA collected for legitimate law enforcement or medical purposes may be shared with other parties and may lead to discrimination and unconstitutional violations of privacy. They maintain that law enforcement agencies have not shown sufficient reason for keeping DNA samples, especially from people who turn out to be innocent.
Supporters of DNA testing in law enforcement believe that the benefits outweigh privacy concerns. They hope that the United States will follow the example of Britain, where law enforcement agencies have been gathering DNA samples from all suspects and arrested persons since 1995. In the United States, issues of access and use will remain at the center of the debate over DNA testing for some time to come.