Deciphering Daddy's DNA
Genetic advances have improved paternity tests
The simplicity of gathering DNA, and the public's growing knowledge that every used soda can tells a story, has increased the opportunity for fraud in paternity cases. Kerkorian's former wife admitted using saliva from one of his grown daughters in an attempt to prove that Kerkorian was Kira's father. State child-support programs, which pay for the bulk of paternity testing, require that the parties being tested appear in person at a designated site in order to establish a "chain of custody."
Chain of custody is also crucial in immigration cases. Increasingly, United States embassies require paternity testing to verify the relationships of people seeking to join family members in the United States. Terry Carmichael, vice president of marketing and sales at Gene Tree in Salt Lake City, says 5 percent of the lab's paternity work involves immigration. Labs that are certified by the international blood bank association AABB follow standards to assure a chain of custody. Still, fraud happens. Men will send a buddy in to give a sample, or a woman will bring in a different child.
Know now. Traditionally, children aren't tested to determine parentage until they are born. But some parents aren't willing to wait. Chorionic villi sampling and amniocentesis, which are used to test fetal DNA for genetic disorders such as Down syndrome, can also be used to identify the baby's father in the first or second trimester. Dawn, who asked that her last name not be used, found herself shopping for prenatal paternity testing after she went through a rough patch in her life, had a one-night stand, and then found out she was pregnant. "My husband was worried that it wasn't his," she says. "I knew it was my husband's baby, but he wanted to be 100 percent sure that it was his, so he could be excited through the pregnancy." The couple found Gene Tree on the Internet, and paid $445 for the test. Dawn's obstetrician agreed to do an amniocentesis, and the sample was compared with those from Dawn and her husband. The baby, to be born this summer, is his. "It would be nicer if it wasn't so expensive," says Dawn, 27, "but it meant more to us to relieve that anxiety and worry."
In 1997, researchers in Hong Kong discovered that bits of DNA from a fetus float freely in the mother's blood throughout pregnancy. Since then, scientists have been hard at work trying to figure out how to use that DNA to devise better tests for genetic disorders like Down syndrome. But companies like Gene Tree are already marketing baby-gender tests based on free fetal DNA, and Carmichael predicts that paternity tests are 18 months away. "It's annoying," Farideh Bischoff, a molecular cytogeneticist and associate professor at Baylor College of Medicine, says of these souped-up versions of "Who's Your Daddy?" that are coming ahead of broader medical applications, the kind she's working to develop.
But people have a way of using science to find out what they really want to know, and Carmichael has no doubt that there will be a market for these paternity tests, too. "We know the answer to the question is very, very important," he says. "We think it will reduce people's anxiety and prepare them for fatherhood."
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