In June 2007, James Watson, a co-discoverer of the structure of DNA, went to Houston to pick up his genome. At a ceremonial press conference at Baylor College of Medicine, scientists handed the 79-year-old Nobel Prize-winner a DVD on which they had recorded a highly accurate reading of all the DNA nestled in the nucleus of each of his cells. There was, however, one glaring gap.
Watson spoke at the conference about the value of genomes to medical research. “I think we’ll have a healthier and more compassionate world 50 years from now because of the technological advances we are celebrating today,” he declared. In addition to giving Watson his genome on a DVD, the Baylor team also put the sequence into the public database GENBANK, where scientists can download it and compare it to other publically available human genomes. But scientists will not be able to see one of Watson’s 20,000 genes. The gene encodes a protein called apolipoprotein E. A variant of the gene, called ApoE4, dramatically increases the risk of developing late-onset Alzheimer’s disease. Watson’s grandmother had died of Alzheimer’s disease, and Watson decided he would rather not know if he carried the variant.
Now imagine taking this sort of revelation to its logical extreme. You’re the parent of a newborn daughter. The doctors take a blood sample from her and run it through a genome-sequencing device. Within a couple days you get a full report on your daughter’s genome. It shows whether she has ApoE4 and how many copies she carries. Does she deserve to know what may lie ahead? Or should she enjoy a blissfully ignorant youth? Because you have her whole genome, and not just a test for a single gene, you can potentially look for a vast number of other gene variants that raise the risk of other diseases of adulthood, such as the BRCA1 gene for breast cancer. Should she get the whole report or not? Will you be prepared for what her genome sequence may reveal about you or your spouse, since she got all her DNA from you? And would the specter of a deadly gene loom over your years raising your child?
“The notion of sequencing everyone at birth has been around for a long time in a pie-in-the-sky way,” says Robert Green of Brigham and Women’s Hospital. But now, Green says, it’s rapidly approaching reality.