Most parents want their babies’ genome sequenced, study finds

by jeeg 5. January 2015 21:20

 

By sequencing the billions of chemical letters in a cell’s DNA, which make up the human genome, scientists may be able to better estimate the risk of a person developing cancer, heart, biochemical and metabolic diseases.

But while a majority of parents surveyed in a new study said they would be interested in having some — or all — of their newborn’s genome sequenced, some researchers raise ethical questions about how much families should know about the results.

“Of course, sequencing babies at birth captures people’s imaginations because the idea is that you could create this book of life,” said Dr. Robert Green, a geneticist and an author of the study done by researchers at Brigham and Women’s Hospital and Boston Children’s Hospital. “You could use it as a reference to look up anything that happens to the child — if the child develops a medical problem, you’ve got the sequence done and ready to examine.”

In the study, within 48 hours of their baby’s birth, researchers gave 514 moms and dads a quick rundown on the human genome — inheritance patterns, genetic risk and implications — then asked if they would hypothetically be interested in having their baby’s genome sequenced. Most said they would.

Most babies born in the U.S. already receive a test that screens for about 30 different types of genetic disorders, but genome sequencing can be more comprehensive.

“The general principle is that the earlier you do this the more chance you have of picking up disorders that exhibit themselves early in life,” Green said.

Regardless of their age, race or education, 83 percent of parents in the study said they’d be somewhat, very or extremely interested in having their newborn’s genome sequenced, though parents who were already concerned about their baby’s health were less likely to be interested.

A first step

The study was the first step in what researchers hope is a safe, controlled look into the effects of genetic screening before a market for it barrels forward.

The cost of sequencing has dropped swiftly in the past few years, and could soon become affordable enough for many families to consider. In 2001, it cost $100 million to sequence a human genome. In the past six years, the price dropped from about $1 million to less than $10,000 for sequences funded by the National Human Genome Research Institute.

But as the field moves forward, many questions remain unanswered: Should doctors report only childhood illnesses, and not adult ones that no intervention can fix? When should doctors order sequencing, and when should insurance companies pay for it?

The next step in the study, pending approval, is the BabySeq Project, in which researchers will sequence groups of sick and healthy babies.

The goal is to determine whether sequencing can help doctors diagnose babies in intensive care. The genomes of sick adults and children already are being sequenced to help doctors in making diagnoses, said Green, who is helping to lead BabySeq.

Sequencing healthy newborns’ genomes is more controversial.

“You could potentially find some genetic predisposition that could alert you to problems in the future and be in the position to mitigate or prevent them,” Green said. On the other hand, it might find genetic glitches doctors don’t understand or worse, genetic predispositions for diseases that modern medicine can’t fix.

Not definitive

Part of the controversy surrounding genome sequencing is the nature of genetics. In most cases, being predisposed means a person is more likely — but not certain — to develop a disease, said Mildred Cho, associate director of the Stanford University Center for Biomedical Ethics and an associate professor of pediatrics and genetics.

Knowing a child could develop a disease “might sort of change the way that parents feel about the kids and raise them, maybe being overprotective or sort of hovering a lot and going to the doctor more often than they might,” Cho said.

For example, if parents who knew their child was at risk for cystic fibrosis brought their child to the doctor frequently as a precaution, they could expose the child to more germs and, as a result, make them sicker. Families could inadvertently learn more than they want to know about other family members’ genes, too.

“If you find out that there’s a dominant disorder (in) a baby, then the siblings have a 50 percent chance of having it, too,” Cho said.

There are also concerns about the accuracy and comprehensiveness of the testing, Cho said.

“People think that whole genome sequencing must be the gold standard of looking at DNA, but it really doesn’t detect all types of genetic structures,” Cho said, noting that an ultrasound can pick up some conditions that genetic sequencing cannot.

Greta Kaul, San Francisco Chronicle

 

 

 

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