Podcast Explores Newborn Screening for DMD

An April 2012 podcast from Nationwide Children's Hospital in Columbus, Ohio, explores the implications of a recently developed strategy for newborn screening for Duchenne muscular dystrophy (DMD).

The podcast is part of a Nationwide Children's series called "This Month in Muscular Dystrophy."

It features neurologist Jerry Mendell, a longtime MDA research grantee, director of the Center for Gene Therapy and co-director of the MDA Clinic at Nationwide Children's, discussing his group's proposed two-step approach to DMD newborn screening.

One sample, two tests

The approach proposes that testing for DMD could be done on the single dried blood spot derived from a heel stick performed at birth on all newborns. Currently, about 30 screening tests are run on this single blood sample.

First, the sample would be screened for elevated creatine kinase (CK); second, for those samples showing markedly elevated CK, DNA analysis of the dystrophin gene would be performed on the same blood spot, with no need for a second blood sample from the baby.

CK is an enzyme that leaks out of degenerating muscle cells and indicates nonspecific muscle damage. The dystrophin gene, which codes for a crucial muscle protein, is mutated in DMD.

A pilot project conducted in Ohio screened 37,749 newborns using this two-step process and identified six newborn boys as having dystrophin gene mutations. (DMD is an X-linked disease and affects boys almost exclusively.)

Earlier diagnosis would allow earlier treatment

In the April podcast, Mendell emphasizes that the need for early identification of children with DMD appears compelling because of the many experimental therapies in the pipeline. These therapies, such as gene therapy and exon skipping, he says, will probably work best if started as soon after birth as possible, before much muscle damage has occurred.

And, he notes, even without these experimental therapies, currently available glucocorticoids (corticosteroids), such as prednisone, now used to treat children with DMD, might be even more effective if started earlier.

"Glucocorticoids are already on the table, exon skipping has great potential, and we're moving toward gene therapy," Mendell says in the podcast.

Mendell noted that MDA will be hosting a workshop (an MDA "Muscle Symposium") in September 2012 "with expertise on the muscular dystrophy side and on the newborn screening side," in order to establish guidelines for going forward with newborn screening for DMD.

Screening paper highlighted

The two-step approach to newborn screening for DMD was initially described in a paper by Mendell and colleagues, published in March 2012 in Annals of Neurology (and online in January).

Eva Feldman, president of the American Neurological Association, which publishes Annals of Neurology, recognized the paper as the March 2012 "President's selection," indicating that newborn screening for DMD is considered an important topic in the research community.

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