AAP: Newborn screening: past, present, and future

October 13, 2008

Newborn screening has been a major advance in preventative medicine, Harvey Levy, MD, FAAP, explained. However, are too many infants being diagnosed due to newborn screening?

Newborn screening has been a major advance in preventative medicine, Harvey Levy,MD, of Children's Hospital Boston explained. However, are too many infants being diagnosed due to newbornscreening?

Newborn screening began with the discovery of phenylketonuria (PKU). The severityof the disease, the inability to diagnose it combined with the ability to treatit, set the criteria for what other diseases could be screened, such as maplesyrup urine diseases and homocystinuria. When urine screening became an adjunctto newborn screening, it revealed that many other diseases being screened werenot important, and even benign.

The development of tandem mess spectrometry, however, changed newborn screeningby providing a single assay for multiple disorders, offering increased efficiency.It expanded newborn screening into fatty acid oxidation disorders, organic acidemias,and urea cycle disorders. Consequently, there was a rise in the frequency of metabolicdisorder diagnoses, Levy said. It eventually prompted questions: are too manyinfants being diagnosed due to newborn screening? Do all the new diagnoses indicatea previous underdiagnosis?

“We are probably diagnosing some infants with newborn screening who wouldnot have been diagnosed clinically,” Levy said, adding, “We have gottenaway from preventative therapy” as one of the criteria for including a diseasein newborn screening. This is evidenced by screening for metabolic disorders andcystic fibrosis.

Currently, there are pilot studies looking at other diseases for newborn screening,such as Fragile X. Diseases under consideration for newborn screening includeWilson disease and Duchenne muscular dystrophy. Levy also said that whole genomescreening will eventually be included in newborn screening. However, he cautionedthat the future of newborn screening holds new opportunities for both good andharm. There have been unnecessary treatments, diagnoses, and anxiety in families,he said.