Expanded Newborn Screening Could Save Infants’ Lives

from Caring For Our Future, Spring 2005

By Kristin Kelly, Publications Editor, The Children’s Hospital

Many Parents Unaware of Genetic Testing

It’s a simple test: A caregiver pricks a newborn baby’s heel, places the blood on a card and mails it to the University of Colorado at Denver and Health Sciences Center (UCDHSC).

The test may be simple, but what it does is anything but: it can detect more than 20 metabolic disorders, many of which can cause mental retardation, physical disability and even death.

The tragic part is that not only is the test not mandated for all newborns in Colorado , most parents don’t even know it exists.

Since the 1960s, all states have mandated tests for some congenital disorders. In Colorado , babies are screened at birth for seven disorders: Phenylketonuria (PKU), congenital hypothyroidism, galactosemia, biotinidase deficiency, sickle-cell disease, congenital adrenal Hyperplasia and Cystic Fibrosis.

Testing for the more than 20 metabolic disorders, called Expanded Newborn Screening, is not required by the state, although it should be, said Stephen Goodman, MD, professor of Pediatrics/Cell and Developmental Biology at UCDHSC and The Children’s Hospital.

“If the test is not offered, kids with these diseases are either not diagnosed at all, or not diagnosed before they develop symptoms,” he said. In fact, he said, the cost of treating these diseases is much higher than the cost of offering Expanded Newborn Screening. The state funds the test for seven disorders, but because Expanded Newborn Screening isn’t mandated, insurance won’t cover it. Parents must pay for the $25 test out of their own pockets.

Parents Can Request Screening

If parents are not offered Expanded Newborn Screening, Dr. Goodman said, they can request it from their pediatrician or a nurse at their birthing hospital. Doctors recommend that blood be taken when the baby is 24 to 48 hours old. However, a pediatrician also can perform the test in the first week of the baby’s life. The test is not recommended for infants older than 2 months.

“The sensitivity of the test decreases as the child gets older,” said Michael Woontner, research associate in UCDHSC’s School of Pediatrics .

Doctors also caution that Expanded Newborn Screening does not replace the state-mandated screening for seven disorders – babies should get both tests.

Parents may not think a child needs Expanded Newborn Screening because the child looks healthy, but a child may not develop symptoms for months. Many parents also think that if their family has no history of metabolic disorders, their child doesn’t need to be tested, Dr. Goodman said. But many children with these disorders come from families with no history of the condition.

Although these metabolic disorders are rare and affect fewer than 20 of the 70,000 children born in Colorado each year, early treatment is necessary to prevent serious harm or even death, said Dr. Goodman. At Children’s Inherited Metabolic Diseases Clinic, he sees the children who weren’t screened and developed diseases. The diseases can’t be cured, but can be managed with a special diet or other medical treatment.

UCDHSC began offering Expanded Newborn Screening about two years ago, Dr. Goodman said, when the school realized that no one else in the state was doing it. The university purchased a tandem mass spectrometer, an expensive instrument that weighs and sorts molecules. Blood samples from newborns have hundreds of compounds in them, but researchers are only interested in a few dozen, Dr. Goodman said. The compounds researchers are looking for have certain common and unique characteristics and are members of a chemical class or family such as amino acids or fatty acids.

Once the test is run through the tandem mass spectrometer, results are reported to the child’s pediatrician.

UCDHSC State Experts

UCDHSC screens roughly 800 to 1,000 samples each month, Dr. Goodman said. In fact, he said, he and his team are known as the state experts in Expanded Newborn Screening. The trouble with that, he said, is that UCDHSC isn’t funded to do the tests.

“The more samples we get, the less time we have to do research,” he said.

And that’s why he hopes the proposal to make Expanded Newborn Screening mandatory in Colorado makes it to the Legislature this year. Quite a few states already have made the screening mandatory, including California , Iowa , North Carolina , Minnesota and Illinois .

But not every state can afford the pricey tandem mass spectrometers or the costs associated with doing the tests.

“This is a national tragedy,” said Harry Hannon, MD, chief of the Centers for Disease Control’s newborn screening branch, which estimates that testing shortfalls result in the sometimes-preventable illness or death of several thousand children every year. “Every baby in this nation should be screened with these expanded tests.”

For more information on Expanded Newborn Screening or to request a screening kit to bring to the hospital at the time of delivery, call (303) 315-7301.

Disorders That May Be Identified By Expanded Newborn Screening

• Maple Syrup Urine Disease (MSUD): Defect in breakdown of amino acids from proteins. Could result in failure to thrive, neurological complications and death in the newborn. Treated with restricted protein diet. Frequency: 1 in 175,000.
• Other Amino Acid Disorders: In addition to PKU and MSUD, screening can detect a number of additional defects in amino acid breakdown.
• Medium Chain Acyl-CoA Dehydrogenase (MCAD) Deficiency: Defect in the breakdown of fat. Generally presents within the first two years of life with recurrent episodes of low blood sugar provoked by fasting. It also is a significant cause of unexplained infant death. Treatment includes avoidance of fasting and reduction of dietary fat. Frequency: 1 in 10,000.
• Other Fatty Acid Oxidation Disorders: In addition to MCAD deficiency, screening can detect a number of additional defects in fat breakdown. Clinically, these disorders are similar to MCAD deficiency and the treatment is similar. Combined frequency: 1 in 50,000.
• Methylmalonic Acidemia: A group of defects in the breakdown of organic acids that can involve a primary enzyme deficiency or a number of defects in vitamin B12 transport or synthesis. Symptoms include acidosis and failure to thrive. Symptoms may be severe very early in infancy or mild to severe later in infancy. Treatment involves dietary protein restriction and/or vitamin B12 supplementation. Combined frequency: 1 in 50,000.
• Propionic Acidemia: Defect in the breakdown of organic acids that may present within the first few days of life with poor feeding, vomiting, seizures, acidosis and coma, or later in life with a milder clinical presentation. Treatment involves protein restriction and carnitine, glycine or biotin supplementation. Frequency: 1 in 50,000.
• Isovaleric Acidemia: Another defect in the breakdown of organic acids that may present in the newborn period as an acute episode of acidosis with vomiting and coma or as a chronic form with episodes of acidosis. Treatment involves protein restriction and carnitine or glycine supplementation. Frequency: 1 in 50,000.
• Glutaric Acidemia-Type I: Defect in organic acid breakdown that presents within the first years of life with impaired movement and muscle tone. Frequency: 1 in 30,000.
• Other Organic Acid Disorders: Screening can detect a number of other disorders. Clinically, they are similar to the above defects and treatment is similar. Combined frequency: 1 in 30,000.

References

“For the Health of Your Growing Family,” UCDHSC Biochemical Genetics.

“Expanded Newborn Screening: A Parent’s Guide,” UCDHSC Biochemical Genetics.

“A Simple Test Could Have Saved Ben’s Life,” People Magazine, Aug. 2, 2004.