Rare But Deadly
Some simple, cheap blood tests could save thousands of kids' lives every year
Two cousins, two babies, two states. The six years between the birth of Toni Cline's daughter and Sharon Allen's son made all the difference between tragedy and joy. Kasie Cline died in Richmond, Va., in 1991 of a rare disorder called medium-chain acyl-CoA dehydrogenase, or MCAD.
Joshua Allen, born in 1997 in Wilson, N.C., with the same disorder, is today a healthy, energetic 7-year-old. What happened after Kasie's death and before Joshua's birth was the development of technology called tandem mass spectrometry, capable of screening newborn infants for MCAD as well as a variety of other rare disorders. With screening, physicians and metabolic nutritionists can develop treatment plans, often as simple as dietary changes, to save lives.
But even today, which side of a state border an infant is born on can make a life-or-death difference. Some states screen for as few as six disorders, while others screen for more than 50. That may change soon, as Secretary of Health and Human Services Michael Leavitt acts in the next few weeks on the recommendations of the American College of Medical Genetics' newborn screening expert group. The panel recommended that all 50 states screen for 29 rare disorders. All are treatable if discovered early, and none is obvious to pediatricians in the hospital nursery. Together, they affect no more than 5,000 of the 4 million infants born in the United States annually. Some are fatty-acid disorders, others involve a toxic buildup of amino or organic acids. Some hit select populations, like sickle-cell disease, which affects African-Americans.
Too late. Without screening, the disorders are discovered only when the infant becomes deathly ill. A child with undetected sickle-cell disease, for example, is vulnerable to life-threatening infections. When the disease is known, the child can be treated with antibiotics before any infection takes place. "We have preventive interventions when they're identified early," says F. Sessions Cole, newborn medicine director at St. Louis Children's Hospital.
Consequences of delayed treatment of these hidden disorders can include seizures, retardation, and death. "We had a classic example of an infant in North Carolina who presented with glutaric acidemia [GA-1] and overwhelming brain damage," says Joseph Muenzer, associate professor of pediatrics at the University of North Carolina and chair of the state's Newborn Screening Advisory Committee. "The baby was born in Virginia, and the family moved to North Carolina. If the child had been born in North Carolina, there's a chance the problem would have been avoided." That's because testing for GA-1 is required in North Carolina. Virginia has recently added the disease to its panel of tests but has not yet implemented statewide screening.
"Parents are oblivious to this," says Dianne Frazier, professor of pediatrics and a metabolic dietitian at UNC. "They see the Band-Aid on the baby's heel, but they don't know which tests have been done." As recently as five years ago, only North Carolina and Massachusetts required that parents be offered the option of new screening tests utilizing tandem mass spectrometry to detect rare metabolic disorders. At least 35 states have increased the number of screening tests offered for infants, and more plan to do so. State movements have largely been led by parents who have lost a child; there is no uniform, national plan.
advertisement
