The Tuesday afternoon sessions of MDA’s 2018 Clinical Conference focused on best practices in newborn screening. Augmentative communication, pediatric-to-adult transition, respiratory health and care coordination also were covered in parallel sessions.
Among the highlights:
R. Rodney Howell, M.D., from the Miller School of Medicine, University of Miami, talked about the history of newborn screening (NBS).
The practice of newborn screening originated in Norway in the 1930s, following the discovery that the underlying cause of the disease phenylketonuria (PKU) is an inability to metabolize the essential amino acid phenylalanine. PKU is treatable with a modified diet, but in order for treatment to be effective it must begin in early infancy — which means testing for the disease has to be conducted shortly after birth.
A public health program for newborn screening was launched in the United States. However, individual states added a number of different conditions to their newborn screening panels, leading to variability in what disorders were screened for from state to state. To address this, the U.S. Congress established the Secretary’s Advisory Committee on Hereditary Disorders in Newborns and Children. The expert group convened in 2002 and published a report in 2006 that was guided by evidence-based data and contained a list of conditions the group recommended be included on the newborn screening panel.
The recommended uniform screening panel (RUSP) is based on the feasibility of testing, the severity of the disease and the availability of one or more treatments, and may include conditions for which onset may be at birth or later in life. Patient advocacy groups are instrumental in state-by-state implementation.
With the emergence of new treatments, neuromuscular care centers have begun seeing screened newborn babies whose early diagnoses can trigger early treatment and long-term follow-up care that can help save their lives. And with additional treatments coming online soon, we’re likely to see more diseases added to the RUSP in the near future.
Currently, the only neuromuscular disorder on the RUSP is Pompe disease, which has an FDA-approved treatment. Following the 2016 approval of Spinraza, the Advisory Committee has recommended that spinal muscular atrophy (SMA) be included on the RUSP, and efforts to add Duchenne muscular dystrophy (DMD) are underway.
Newborn screening in DMD
Robert Griggs, M.D., FAAN, University of Rochester Medical Center, said, “There is virtually no established precedent for withholding a treatment that improves a disease.”
In addition, Griggs noted, MDA is aggressively pursuing newborn screening preparedness for DMD and other neuromuscular diseases.
In cystic fibrosis, newborn screening led to dramatic benefit in patients long before molecular treatment was available. Early recognition and the generation of standards of care have transformed the course of the disease.
An FDA-approved treatment exists for DMD that improves strength; the corticosteroid Emflaza was approved in early 2017. Results from treatment with corticosteroids have been observed beginning at 10 days, with continuous improvement for 18 months. Early treatment is beneficial, with diagnostic delays leading to worse outcomes.
In China, 25 percent of individuals with DMD receive corticosteroids. However, in cases where diagnosis is made after these boys begin using a wheelchair, life expectancy is fewer than 20 years.
The annual outcomes of the two-tier newborn screening test for DMD show that of those who show high levels of creatine kinase (CK), 50 percent are diagnosed with DMD, while the rest have other forms of neuromuscular disease including Becker muscular dystrophy, limb-girdle muscular dystrophy and congenital myopathy — it’s important to determine what to do in these cases.
MDA is grateful to the following companies for their support of the 2018 Clinical Conference:
- Strength for Life supporters — Biogen, PTC Therapeutics
- Muscle Champion supporters — AveXis, Santhera Pharmaceuticals, Inc., Sarepta Therapeutics