NYTimes- Screening for Rare Genetic Disorders Now Routine in Newborns
creening for Rare Genetic Disorders Now Routine in Newborns
By RONI CARYN RABIN
When David Swift’s baby girl Giana was born at Santa Monica U.C.L.A. Medical Center six years ago, a nurse approached to ask if the baby could participate in a pilot program to screen newborns for dozens of rare genetic disorders. It involved little more than a heel prick blood test, but Mr. Swift, a 33-year-old first-time father, declined.
The nurse persisted, asking the question again and again, until Mr. Swift relented. And he’s been trying to find that nurse ever since, because the test, which identified an extremely rare metabolic condition in his newborn daughter, may have saved her life.
Had we not been at that particular hospital, with that particular pilot program and that particular nurse… he said, his voice trailing off. It’s miraculous.
A March of Dimes report released today says all 50 states and the District of Columbia now require newborn screening for 21 or more so-called core disorders recommended for testing. These core disorders, 29 in all, include many rare but potentially disabling or fatal metabolic disorders. Although all states have rules or laws requiring the screenings, Pennsylvania and West Virginia have yet to implement their expanded programs, according to the organization.
The increase represents a big change since 2000, when most states screened for only four conditions and testing practices varied widely from state to state, according to March of Dimes officials.
It’s a milestone, said Jennifer L. Howse, president of the March of Dimes, which advocated for expanded testing. Screening rates in newborns rose from 38 percent in 2005, when the organization began monitoring, to 96 percent by the end of 2008, she said. That’s very, very dramatic.
Twenty-four states do all of the tests, and seven do 28 of the 29 tests, she said. The tests include screens for phenylketonuria, or PKU, a potentially devastating illness that strikes about one in 25,000 newborns, and maple syrup urine disease, so-named for the infant’s sweet-smelling urine, which affects one in 100,000. More common ailments like sickle cell anemia, which affects one in 400 African-Americans, and cystic fibrosis and hearing loss, each of which affect one in 5,000 children, are screened for as well.
The American College of Medical Genetics developed the list of the 29 disorders recommended for testing. (A list of tests provided by each state can be found at the March of Dimes Web site).
Dr. Howse emphasized that the metabolic disorders on the list are rare but treatable, and if they’re not detected and treated, they’re catastrophic and can lead to infant death.
In most cases, she added, the babies look perfectly healthy.
New technology, specifically the advent of a technique called tandem mass spectrometry, provided the means to identify many conditions from just a tiny sample of blood, she said.
Mr. Swift’s daughter was found to suffer from a condition that makes her unable to break down leucine, an essential amino acid in protein. Only about 30 cases of the disorder have ever been documented and, undiagnosed, it could have led to mental or physical disability, or even death.
Instead, Giana was put on a modified diet with very little protein and takes a special protein formula free of leucine, Mr. Swift said.
She is beautiful, healthy, precocious, 99th percentile height and weight, just wonderful, Mr. Swift said. That test saved her life.