Improving Newborn Screening for Spinal Muscular Atrophy

Crystal Proud, MD

Spinal Muscular Atrophy (SMA) Awareness Month, observed annually in August by the patient and clinician communities, has the goal of bringing more attention to the genetic disorder, which affects motor neurons in the spinal cord and leads to muscle wasting and weakness. For SMA Awareness Month in 2024, CGTLive®'s sister site NeurologyLive® reached out to Crystal Proud, MD, the director of neurology and neuromuscular medicine at the Children’s Hospital of the King’s Daughters in Norfolk, Virginia, for her perspective on important aspects of awareness with regard to SMA.

Proud drew attention to the accomplishments made with expanding newborn screening practices for SMA to all 50 states, but noted that some challenges still remain. She pointed out that numerous barriers to rapid treatment of patients following newborn screening exist and emphasized the need to do more work to overcome these barriers.

CGTLive: What are some areas that are doing well with regard to SMA awareness, and what aspects need more work?

Crystal Proud, MD: I think recently we've done a nice job of raising awareness about newborn screening. Now we screen for the possibility of babies having SMA in all 50 states, which is a huge accomplishment. But this still leaves an estimated 5% of children being undiagnosed through the newborn screening program, and those children will be diagnosed based on symptoms. We do still need clinicians to be thinking about the possibility of SMA in a child who is presenting with weakness. That's something that we probably need to make sure that we bring to the forefront. It's been really an exciting time in clinical research, but our job is not done yet. I think we're doing a great job of highlighting the progress that we've made, but we still require comprehensive, multidisciplinary care and ongoing efforts to really optimize the outcomes of the kids that we're seeing and the adults that we're seeing impacted by SMA.

How can the efficiency of newborn screening and treatment be improved?

It's important and critical that we recognize that every day that a child with SMA goes untreated is a day where we could potentially be losing very valuable motor neurons. Those motor neurons can impact the long-term functional impacts of our patients. If we want to optimize their long-term motor function, their abilities overall, their capacity for independence and gaining skills, then the goal would be to treat as soon as possible. Barriers to that are numerous. Even if we have newborn screening in place, we know that there can be a delay in getting samples to the lab. There can be different processing times that different states' labs have. You may have one lab in one state that processes on a daily basis, and you may have another state that batches their tests together, and this can impact the timing of those results getting to the clinician. Then once we get those tests, we also need to make sure that we're confirming those tests. Usually that means a secondary test that ultimately confirms the patient's diagnosis and oftentimes will give us the SMN2 copy number which can play a role in some of the opportunities we might present to them, whether it be a commercially available treatment or a research protocol that they can enter into.

The next step is obviously authorizing treatment after you've prescribed it and then getting that treatment shipped to the location where you're going to be providing it. Each of these steps along the way can prove to be a barrier to timely treatment, and so if we examine each of these closely, we'll be able to hopefully cut down on the time it takes from diagnosis to intervention.

This transcript has been edited for clarity.