The Newborn Screening Mucopolysaccharidosis Type I (MPS I) Pilot Program

Identifying the youngest victims of a rare genetic disorder

The Eunice Kennedy Shriver National Institute of Child Health and Human Development

Mucopolysaccharidosis Type I (MPS I) is a rare genetic condition that affects about one in every 100,000 newborns nationwide. This disease causes a buildup of a specific kind of sugar in the lysosomes of cells, and in its most severe form—known as Hurler’s Syndrome—usually causes death before the age of 10.

In 2016, the U.S. Department of Health and Human Services added MPS I to its Recommended Uniform Screening Panel (RUSP), which advises states on which conditions should be screened in newborns. However, because RUSP is a recommendation rather than a mandate, many states have yet to institute screening for MPS I. To demonstrate the feasibility of screening for this condition, we teamed with Duke University, the University of North Carolina-Chapel Hill, and the North Carolina State Laboratory of Public Health to screen more than 60,000 newborns in North Carolina.

Our method to screen for MPS I involved detecting enzyme activity from a dried blood spot specimen using tandem mass spectrometry, a common technique that is currently used to detect about 50 other conditions in newborns. Before starting screenings, however, we were careful to develop supplementary materials about MPS I, including a website and a brochure, for use by parents and health care providers. We also retained the services of a genetic counselor who provided consultation in case of a screen positive result. Educating parents, especially pregnant women who may be carrying a child with MPS I, gives them the opportunity to adapt to the complications the disease may bring.

Notably, we did identify one newborn with the most severe form of MPS I. Because we caught the disease in its earliest stages, doctors were able to treat this child with a stem-cell transplant, which will allow the child to avoid the most deleterious consequences of severe MPS I and lead a relatively healthy life. We also identified 18 newborns with genetic variants within the MPS I gene (IDUA), which are not known to cause disease and require no treatment.

The success of our study demonstrates to other states that screening for MPS I can be done as successfully and as reliably as screening for other newborn diseases. The fact that we were able to identify one infant with severe MPS I, and facilitate the proper medical intervention, shows the potential benefits of screening for this rare disease on a nationwide basis.