Suzanne Critchfield, a 68-year-old grandmother in Oakley, Idaho, totes around her laptop to show off her latest acquisition: a family tree based on her DNA. She found the names of hundreds of ancestors in Denmark and England and, to her surprise, one in Spain. "You can only go so far back in the paper documentation," says Critchfield, an amateur genealogist who previously had tracked her roots to 17th-century Boston. "This goes back so much further, and it's so much more reliable." She has E-mailed other users of GeneTree.com who are newfound genetic relatives to trade family histories.
Anne Wojcicki was at brunch with friends in Silicon Valley the other day when they decided it would be fun to see which of them had a genetic predisposition for being a night owl. "I just pulled out a laptop," Wojcicki says. The friends logged on to her company's new website, where they all had stored their genetic profiles, and looked to see who had a DNA variation associated with altered sleep patterns. "It's kind of a fun thing with things like circadian rhythm, to see who you're similar to," says Wojcicki, cofounder of 23andme, a start-up in Mountain View, Calif., that sells individual gene scans.
Critchfield and Wojcicki are advance scouts in a sudden explosion of efforts to make something useful out of the human genome: genetics as a social networking tool. It's essentially taking DNA-testing capabilities used by medical researchers and wedding them to a social networking website like MySpace. Whether such retail genetics will create meaningful new human connections or be a mere hobby remains to be seen. But uncertainty hasn't dampened the enthusiasm of genetic entrepreneurs: "I'm convinced that in the next five to 10 years every educated person in the western world is going to have a profile like this," says Kári Stefánsson, CEO of Decode Genetics (decodeme.com), an Icelandic company that, like 23andme, started selling gene scans to the public in November at about $1,000 a pop. The truly adventurous can sign up later this month for the Personal Genome Project, which is recruiting 100,000 volunteers to post their entire genomes along with their medical information on the Web, where it can be probed by medical researchers—or genetic voyeurs. "It's an experiment, technological and sociological," says George Church, a Harvard geneticist who launched the nonprofit project, which he hopes will test the scientific and ethical issues surrounding genetics.
The scans that enable this new form of social networking are far different from older genetic tests that pinpoint genes that cause diseases like cystic fibrosis. Instead, they look for small variations along a human being's 23 pairs of chromosomes that can be used to gauge a predisposition for health problems like heart disease or diabetes—or to trace ancestry. Until very recently, such a broad scan—23andme charts 600,000 single nucleotide polymorphisms, or SNPs, and decodeme nearly twice that—would have cost millions. Still, SNP scans cover about 0.02 percent of a person's DNA, compared with close to 100 percent of the 3 billion bits of DNA in a whole genome scan.
Genes go Retail
People can now compare DNA with that of friends online, trace family history, or size up health risks. Options include: