Will Genome Sequencing Make Us Smarter About Dealing With Diseases in Our Genes—Or Just More Anxious?

Doctors could use our genetic map to pinpoint the best treatment for our diseases. But how much do we want to know about what’s lurking in our DNA?

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Mapping a child's genome could be something available to all parents in the coming years. But is the procedure always good? National Institute of Standards and Technology

There was a time when parents of newborns were perfectly content to know only a few basic things about their babies: their height, their weight, their apgar score, and which side of the family should get the credit for making the kid so adorable.

But a graduate student at the University of California, Davis named Razib Khan wanted to know much, much more about his son, born a little more than a week ago. And what Khan did, he contends, will become standard procedure for moms and dads of the 21st century.

After he managed to convince his wife’s doctor to provide him with a small tissue sample from the placenta during the second trimester of her pregnancy, Khan, a doctoral candidate studying feline genetics, was able to roughly sequence his son’s genome—essentially giving he and his wife the ability to glimpse into their child’s future. By most accounts, that made the boy the first healthy human in the U.S. to have his genetic makeup deciphered before he was born.

Doctors do genetic testing of fetuses now, but only for diagnostic reasons—for instance, if the doctor believes the developing child may have a birth defect. Khan had no compelling medical reason to explore his baby’s genes before he was born.  His motivation, he told M.I.T’s Technology Review,  was “more cool than practical.”

Considering the odds

Khan is probably right about the inevitability of parents having access to the genetic maps of their children before they’re born, particularly now that so much data can be gleaned from a single drop of blood or a little spit. What’s not so clear is what the parents can and will do with it.

Once you go beyond looking for specific genetic mutations—such as those that cause Down syndrome or cystic fibrosis—and begin exploring a fetus’ whole genome, genetic mapping moves into a fuzzier territory: a place in which the information is no longer deterministic, but instead merely predictive. Genetic data may suggest that a child is more likely to develop a certain condition, such as diabetes or heart disease, but it's more a possibility than a diagnosis, since other behavioral and environmental factors also play a role.

What happens, for instance, if a genetic map indicates an unborn child will be prone to a particularly debilitating disease when they reach adulthood?  Would that make parents consider terminating the pregnancy? Then there’s the matter of genome editing, which could soon make it possible to change a baby’s DNA long before the onset of a disease. For instance, the parents of a baby girl with the gene that significantly raises the risk of developing breast cancer may be able to choose to have it removed. That seems a reasonable choice. On the other hand, what if the same process would allow parents to increase the likelihood that their child will be particularly athletic or have a certain hair or eye color? That makes the concept of tailor-made kids closer to reality than science fiction.

Too much information?

At the moment, though, most scientists choose not to go there. But research institutions such as the National Institutes of Health (NIH) are taking a hard look at what happens when parents are given a forecast of their child’s biological future.Not long ago, NIH announced a $25 million, five-year study of the potential benefits and consequences of sequencing the genome of every newborn baby in the U.S.

It's a venture that involves researchers from a number of different universities and hospitals, including Boston Children’s Hospital, Brigham and Women’s Hospital, Children’s Mercy Hospital in Kansas City and the Universities of California, San Francisco and North Carolina at Chapel Hill, all of whom will analyze different aspects of genome sequencing.

The Boston hospitals, for example, will focus on the impact genetic data has on the medical care a child receives in its early years: Will parents be more attentive to a child’s health and the habits it develops if they know he or she may be more prone to certain diseases?  How much do most pediatricians really understand about what a child’s genome means? And how do they communicate that meaning and the real level of future risk?

The study at North Carolina, meanwhile, is designed to look closely at the ethical, legal and social issues involved in helping doctors and parents make informed decisions from genome sequencing, particularly as they relate to children born into multicultural families.

Watch Eric Green, director of the National Human Genome Research Institute, explain how genomics are revolutionizing medicine in this video:

Going public

Even with adults, there are plenty of legal and ethical issues that come with the territory of genetic mapping. Of course, you can stay clear of all of them by not having your genome mapped. But that choice may become a less appealing option as we move deeper into the world of personalized medicine.  One of the potential benefits of knowing your genetic makeup is that it could make it far easier for doctors to zero in on the most effective medications and treatments, with the fewest side effects, for each of their patients.

So, aside from finding out about which diseases could be in your future, what’s the downside of having this done?  For starters, whatever you learn about yourself could be very relevant to anyone else who shares your genes. That raises the question of whether patients should get the consent of siblings or other family members before starting the mapping process. Some family members may not want to know about disturbing health conditions hidden in family genes. And if you get bad news, some relatives may feel no choice but to get their genomes sequenced—which could be useful, but also could spread uncertainty and anxiety throughout the family.

Then there’s the matter of privacy. While most of us would assume that genome data, the most personal of information, would remain confidential, some privacy experts say there’s no guarantee it would. An article in Nature last year pointed out a study in which researchers, using an algorithm and information from public databases, could identify people who had been part of genetic studies. 

Maybe in the future, those who have their genomes sequenced can be assured of identity protection. If not, will people find that their predisposition for Alzheimer’s disease or breast cancer be held against them by employers and others? Or, could they discover that they are targeted for marketing of specific medications or treatments by pharmaceutical or diet supplement companies—all based on the diseases that show up in their genetic blueprints? 

Only time will tell.

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