After seven years of unexplained infertility, Ann Najdek-Andrada finally had a son, a baby boy who seemed as perfect as she’d always imagined.
But that fantasy was shattered when Gianni was two weeks old. That’s when the call came saying the child had tested positive for cystic fibrosis — and that it would take nearly four months to find out for sure.
“After everything we’d been through, I was thinking to myself ‘Why does this have to happen?’” said the 34-year-old Mastic, N.Y., mom. “My husband even cried when I was explaining the whole thing to him.”
The weeks dragged by, with Najdek-Andrada juggling the care of a newborn with constant worry about his health.
“Absolutely, waiting was the worst part,” she said. “You’re living in uncertainty.”
When Gianni was finally old enough to have the sweat test that confirms CF, an inherited lung disease that can lead to disability and early death, the news was good. Gianni’s initial newborn screening test was actually a false positive, a kind of mistaken result experts say may affect as many as 200,000 babies in the U.S. each year.
"I was extremely relieved," his mother said.
Gianni Andrada was among some 4.1 million babies born in the U.S. in 2009, one of nearly all newborns who are screened for an ever-growing list of genetic problems aimed at detecting devastating disease before symptoms start.
Every year, between 4,000 and 5,000 infants are correctly identified as having serious genetic disorders, including some that would result in disability or death if they weren't flagged so treatment could begin.
When they’re correct, such tests are invaluable. But when they’re not — and they're not a lot — parents and kids can endure months of repeated tests, special sleeping schedules and stringent diets, plus lingering uncertainty and anxiety, health experts say.
Only 1 in 50 positive tests is true Overall, perhaps only one in 50 of every “positive” newborn screening tests detects actual disease, estimates Dr. Philip M. Farrell, a professor of pediatrics and population health sciences at the University of Wisconsin School of Medicine and Public Health. But that average can vary widely.
On average, for every 10 positive screening tests for cystic fibrosis, one child will actually have the disease, Farrell said.
But for the disorder congenital adrenal hyperplasia — which can cause boys to enter puberty at age 2 or 3 — there are between 100 and 200 false positives for every child truly affected.
“In my opinion, it’s just tragic that parents have to suffer and think about their child having a chronic illness when the child is perfect healthy,” said Audrey Tluczek, an assistant professor and psychologist at the University of Wisconsin-Madison School of Nursing.
In Jennifer Allen’s case, for instance, she was told her 10-day-old daughter, Sophie, had tested positive for propionic acidemia, a potentially fatal disorder that required Allen to wake the baby on a strict schedule for careful feeding. For two weeks last fall, the 25-year-old mother of three from Ontario, Canada, lived with constant fear.
“There was all this pressure on me to keep her fed, to keep waking her up,” Allen recalled. “And then it came back she was perfectly healthy. It felt like a part of what I was supposed to enjoy with her as a newborn was taken away from me.”
Certainly, no one wants to miss sick babies, said Farrell, noting that the consequence of a false negative test "can be devastating." However, experts now say that tackling the problem of false positives must become as important as detecting disease in the first place.
“These families with false positive tests should be cared for and receive the kind of attention they deserve," Farrell said. "There needs to be more attention given to that, in my judgment.”
Dozens of conditions screened Newborn screening has been conducted in the U.S. for more than four decades, starting with mass voluntary testing for phenylketonuria or PKU.
Today’s babies may be screened for dozens of disorders, including a uniform screening panel of 30 core treatable conditions, plus another 25 ailments without a standard treatments, according to the American College of Medical Genetics. States may also screen for additional conditions beyond the 55.
With a few drops of blood from a heel prick, a process called tandem mass spectrometry testing can identify multiple genetic defects at once. Computer analysis has made the process both fast and relatively inexpensive, allowing screening for problems from blood disorders such as sickle cell anemia to conditions such as congenital hypothyroidism.
But just because technology allows such testing doesn’t mean it’s done well — or consistently, noted Dr. Piero Rinaldo, a professor of laboratory medicine and pathology at the Mayo Clinic in Rochester, Minn.
He’s been working for years to improve a system in which newborn screening is conducted on a state-by-state basis, with widely ranging standards — and wildly varying outcomes for those who receive the results. The differences often depend on varied skills, plus political realities and resources. Some states, such as Minnesota, detect far more actual cases of disease with far fewer false positives than others, which may put some families at a disadvantage.
“To me, all children matter the same and they matter a lot,” Rinaldo said.
As it stands now, parents in one state might find that false positives rates are as low as 0.01 percent of all newborn tests, while parents a few states over may find as many as 1.52 percent of those tests are false alarms.
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