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News from Newswise Aug.13, 2007
New Newborn Screening Technology
Revives Old Controversies
Newswise — In 1961, Robert Guthrie
developed a method to test newborns for phenylketonuria, or PKU – a
genetic disorder that prevents the body from processing a protein
found in almost all food, causing severe mental retardation.
Now using just one drop of blood, about 4 million newborns in the
United States undergo testing each year for PKU, as well as a number
of other genetic diseases including sickle cell disease and cystic
fibrosis through state newborn screening programs. And promising new
DNA-based technology is on the horizon that will greatly expand the
medical community’s ability to detect even more genetic
abnormalities in newborns.
While new technology has increased the ability to detect genetic
diseases in newborns, it also has rekindled much of the debate that
has plagued newborn screening for more than 40 years – lack of
federal mandates for testing, the costs of long-term treatment for
children who test positive for a genetic disorder, and testing for
diseases that may have a potential treatment but no cure, among
others.
In a paper published in the August issue of the Archives of
Pediatric & Adolescent Medicine, lead author Beth A. Tarini, M.D.,
clinical lecturer and member of the Child Health Evaluation Research
Unit at the University of Michigan C.S. Mott Children’s Hospital,
outlines the controversies surrounding newborn screening, and
provides insight into the issues that must be addressed for the
continued success of this public health screening program.
“Given the rapid pace of technological advancements, we must make
clear and informed decisions about how we implement new technology
in state newborn screening programs,” notes Tarini. “Many questions
remain about screening uniformity and how best to coordinate
follow-up evaluation for positive newborn screening tests.”
Although newborn screening is mandated by all 50 states, genetic
conditions screened and testing methods used often vary from state
to state. Some states test for the 29 conditions recommended by the
American College of Medical Genetics. Other states, including
Michigan, test for more than 40 conditions, Tarini says.
“Uniformity with newborn screening is key in terms of assuring equal
access and establishing a standard of care,” says Tarini. “But then
the issue becomes how high do you set the bar? Do you only test for
29 genetic disorders, or should newborns be tested for 40?”
New technology is pushing these issues to the forefront. With only
one drop of blood, tandem mass spectrometry – a technology that
medical experts first applied to newborn screening in the 1990s –
can detect at least four times more disorders than previous testing
techniques.
Another recently developed technological advance – DNA microarray –
offers the potential to continue to broaden newborn screening by
making it possible to test for hundreds of potentially
disease-causing genetic mutations.
But the process of newborn screening involves more than just the
initial blood test. A successful public health screening program is
not complete without proper follow-up care, and should include a
systematic collection of long-term data to advance medical research
and treatment of genetic disorders, says Tarini.
“In our society, technology drives us – and medicine is no different.
However, healthcare providers and public health officials are in a
position to make decisions about how we implement technology in a
way that maximizes health benefits for the child, and minimizes any
harm, even if it is unintentional,” she says.
To ensure the continued success of newborn screening, Tarini says
there needs to be improved communication between health care
providers and parents prior to and following screening, as well as
coordination of care between primary care physicians and genetic
experts for infants with positive screening results.
Another issue being debated in the medical community is whether or
not to test for diseases for which a cure or consistently effective
treatment may not be available. A recent report from the C.S. Mott
Children’s Hospital National Poll on Children’s Health that looked
at this issue found that 54 percent of adults endorse genetic
testing to determine if their child is at increased risk for
developing a disease, even when no effective treatment exists.
“Some experts believe that we should not test children for
conditions for which no effective treatment exists. On the other
hand, some parents feel that knowing that their child has a
condition helps families to prepare for their child’s illness, even
if a cure or effective treatment is not available,” says Tarini.
Reference: Archives of Pediatric and Adolescent Medicine, Aug. 2007,
Vol. 161, No. 8.
http://www.newswise.com/articles/view/532241/?sc=rsmn
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