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'Newborn screening' benefits not so clear
Last spring, a federal advisory panel recommended that all states expand ''newborn screening" to check for about 50 rare genetic disorders. The March of Dimes and American Academy of Pediatrics applauded this move as a victory for children's health, and most states now require expanded testing.
Without federal direction, states had varied widely in testing practices, with some states testing for fewer conditions than others. But a new technology -- tandem mass spectroscopy -- has made screening for large numbers of diseases faster and cheaper.
The technology has outpaced medical knowledge, however, raising potential concerns.
For most of the new conditions detected by this technique, it is unknown whether a positive test result means a baby will ever get sick, or whether treatment, if it even exists, helps. According to the New England Journal of Medicine last month, the recommendations were made with weak medical evidence.
Underscoring this uncertainty, last year the British National Health Service chose to apply the technique for only one new disease. The Human Genetics Society of Australia concluded that none of the new tests was ''highly recommended." Massachusetts has long screened for 10 of the diseases, and 19 others are part of a ''pilot study" that's been under way for several years.
The diseases are rare. Of 100,000 babies born annually in Massachusetts, only about 10 a year have tested positive in the ''pilot study," which costs several hundred thousand dollars a year. (Ninety-eight percent of families readily give ''informed consent," suggesting they believe expanded testing likely is beneficial.)
At birth, newborns have their feet pricked and a few blood drops dabbed onto a card. The cards are sent to the state public health lab in Jamaica Plain, where they are tested for the diseases. The test uses beams of electrons to detect telltale chemicals indicating the presence of a genetic disease -- similar to the way automobile emissions testing checks for pollutants.
The idea behind newborn screening is to catch genetic diseases early and treat them before the children develop mental retardation or other serious problems, often by feeding more frequently or with special formulas.
Consider a recent case at Children's Hospital Boston. A 3-week-old boy, born in a nearby state that hasn't expanded screening, developed severe heart failure and was placed on life support and even considered for a heart transplant. An astute doctor sent his blood spots to the Jamaica Plain lab, where the test showed a rare fat-metabolism problem. Treated with sugar and a special diet, the child recovered. Earlier diagnosis and treatment might have prevented the illness, which still could have long-term side effects.
Dr. Mark Korson, a metabolism expert at Tufts-New England Medical Center, told me he supports expanded screening because doctors usually don't think of diagnosing rare metabolic diseases until it's too late. While testing might not distinguish between benign and deadly forms, at least people can make informed choices about whether to treat.
But like drugs that seem promising but later have unforeseen side effects, screening can be dangerous if adopted prematurely. From 1984 to 2003, for example, all Japanese infants underwent testing for a cancer called neuroblastoma, and about 200 healthy-seeming children a year tested positive and were treated with chemotherapy and/or surgery.
Then in 2002, a Canadian study showed that the test was faulty and that in many cases the children didn't have the cancer. The Japanese program was halted immediately. By not screening, Americans had saved $600 million in medical costs and the unnecessary treatment of almost 10,000 children.
Dr. Norm Fost, a medical ethicist from the University of Wisconsin, believes flawed testing decades ago for PKU, a genetic disease that causes mental retardation, led many healthy babies to be treated mistakenly with low-protein diets. ''It caused brain damage in we don't know how many kids, and killed we don't know how many kids," he told the Lancet in April. (Testing and treatment are better now.)
For most of the conditions in the new screen, there is controversy about whether any treatments actually work. But families often take extraordinary measures, even for potentially normal children.
Lauren and Michael Hammer of Westfield, N.J., paid out of pocket for an extended screen, since their state didn't offer tandem mass spectroscopy. It turned out their newborn Evan had SCAD, a condition that can lead to neurological problems -- but not always. On further testing, Evan's father was also positive for SCAD, but he has always been healthy.
Because with SCAD, any periods of fasting theoretically could causes seizures, the Hammers feed Evan every four hours. They set alarms at night. Now 19 months old, Evan had problems with spitting up, and with every illness (he had 10 ear infections in his first year, and an abdominal surgery for an unrelated problem), the family was on edge if he couldn't keep his food down every four hours. For months, we were ''tremendously stressed, physically and emotionally," Lauren Hammer said.
Evan wears a Medic-Alert bracelet, and his car seat has instructions affixed to it, she said, so that ''in case we're in an accident and unconscious, the paramedics will know about his condition." She deferred working in her practice as a social worker for over a year so she could care for Evan. The Hammers will continue the feedings until Evan is old enough to care for himself.
As far as Hammer is concerned, though, newborn screening may have saved Evan. To her, limiting information smacks of paternalism.
In the end, I agree with her that -- now that we can -- we should test, to try to save even a few babies. I worry, though, about the future. If we screen for diseases based on technological prowess rather than evidence of clear benefit, then looming low-cost ''personal genomes" will allow even more complete profiling with no good science to decide how to use the results.
Dr. Darshak Sanghavi, an
assistant professor of pediatrics at University of Massachusetts Medical
School, can be reached at www.darshaksanghavi.com.
