Little Amelia Sloan is a
pioneer: Shortly after her birth, scientists took drops of the healthy baby's
blood to map her genetic code.
Amelia is part of a large
research project that is decoding the DNA of hundreds of infants. New parents
soon can start signing up for smaller studies to explore if what's called
genome sequencing – fully mapping someone's genes to look for health risks –
should become a part of newborn care.
Should parents be told only
about childhood threats? Or would they also want to learn if their babies
carried a key gene for, say, breast cancer after they're grown? Could knowing
about future risks alter how a family treats an otherwise healthy youngster?
And how accurate is this technology – could it raise too many false alarms?
This is the newest frontier
in the genetic revolution: how early to peek into someone's DNA, and how to
make use of this health forecast without causing needless worry.
"This was something
that was looming over the horizon," said Dr Alan Guttmacher, a paediatrician
and geneticist at the National Institutes of Health. Last month, NIH announced
a $25 million, five-year pilot project in four cities – Boston, San Francisco,
Chapel Hill, and Kansas City – to start answering some of the questions before
the technology is widely offered for babies.
Today, the 4 million US
babies born annually have a heel pricked in the hospital, providing a spot of
blood to be tested for signs of at least 30 rare diseases. This newborn
screening catches several thousand affected babies each year in time for early
treatment to prevent death, brain damage or other disabilities. It's considered
one of the nation's most successful public health programs.
A complete genetic
blueprint would go well beyond what that newborn blood spot currently tells
doctors and parents – allowing a search for potentially hundreds of other
conditions, some that arise in childhood and some later, some preventable and
"If I truly believed
that knowing one's genome was going to be transformative to medicine over the
next decade or more, then wouldn't I want to start generating that information
around the time of birth?" asked Dr. John Niederhuber, former director of
the National Cancer Institute who now oversees one of the largest
baby-sequencing research projects to date.Mapping the genomes of newborns
At Niederhuber's Inova
Translational Medicine Institute in Falls Church, Virginia, researchers are
mapping the genomes of newborns, along with their parents and other relatives
for comparison. The long-term goal of the privately funded study is to uncover
genetic patterns that predict complex health problems, from prematurity to
But the experimental tests
will turn up some gene mutations already well-known to cause serious ailments,
and participating parents must choose upfront whether to be told. They don't
get a full report card of their baby's genes. Only ones that cause treatable or
preventable conditions – so-called medically actionable findings – are revealed,
to the family's doctor. That means in addition to paediatric diseases, parents
also could learn whether a baby carries a particular breast-cancer-causing
gene, information useful once she reaches young adulthood.
Nurse Holly Sloan was eager
to enrol daughter Amelia, although she thought hard about how she'd handle any
"If it was something
that we could hopefully prevent through diet or exercise or some kind of
lifestyle change, we could start with that as early as possible," said
Sloan. "I guess I'm just the type of person, I would rather know and
address it." Five months after Amelia's birth she hasn't received any
Ready to be used
Until now, genome
sequencing has been used mostly in research involving curious adults or to help
diagnose children or families plagued by mysterious illnesses.
But many specialists say
it's almost inevitable that DNA mapping eventually will be used for healthy
young children, too, maybe as an addition to traditional newborn screening for
at least some tots. It takes a few drops of blood or a cheek swab. And while
it's still too costly for routine use, the price is dropping rapidly. Whole
genome sequencing is expected to soon come down to $1 000, what it now costs
for a more targeted "exome" sequencing that maps only certain genes
and may be enough.
The NIH decided this was a
window of opportunity to explore different ways this technology might be used.
One of the four teams – at Children's Mercy Hospital in Kansas City – will test
rapid gene-mapping to speed diagnosis of sick babies in intensive care.
Another will look for
narrow sets of genes important in childhood, such as those involved with immune
disorders not detected by today's newborn screening or that alter how a child processes
medication. "It's not going to be some sort of fishing expedition
throughout the genome," said Dr. Robert Nussbaum of the University of
California, San Francisco.
The two other projects
The two other projects – at
Brigham and Women's Hospital in Boston and the University of North Carolina,
Chapel Hill – will go a step further by enrolling healthy infants as they
explore what kind of information parents want about their babies' future.
"We aren't even sure
that genome-scale sequencing in newborns is really a good idea," cautioned
UNC lead researcher Dr Jonathan Berg in a recent Facebook chat to alert the
community about the study. Rather than a one-time mapping, it's possible that
"we will use targeted sequencing at certain times in a person's life, when
that specific information will actually be medically useful."
For those pioneering babies
whose DNA is being mapped already, researchers are "trying to figure out
what is legal, versus ethical, versus good medicine" in revealing results,
said Joe Vockley, Inova Translational Medicine Institute's chief science
Mom and dad may be told
something that their child, once grown, wishes hadn't been revealed. Other findings
may be withheld presently that would be good to know years later, as new treatments
"This is a living,
breathing problem," Vockley said, "not a static decision that's made,
and it lasts for all time."