A Diagnosis at Birth, but No Treatment for Years

When Jennifer Kwon, MD, informed a mother that her 4-day-old baby had screened positive for spinal muscular atrophy, the woman insisted there had been an error and resisted follow-up testing. Kwon, a pediatric neurologist at UW Health in Madison, Wisconsin, eventually persuaded the parent to come in, and the infant received treatment. Now, as some states expand mandated newborn screening for another genetic neuromuscular disorder, Duchenne muscular dystrophy (DMD), Kwon worries clinicians could face similarly difficult conversations but without the same immediate treatment options. “There are no treatments for infants,” with DMD, Kwon said. Disease-modifying treatments for DMD are approved for children beginning at ages 2, 4, or 6, depending on the drug. None are approved for newborns. The progressive genetic disease causes muscle weakness and can lead to serious disability and premature death. Children are typically diagnosed around age 5, often after years of developmental concerns and medical visits. Newborn screening aims to shorten that delay and identify the disease before symptoms appear. Proponents say earlier identification could help families establish specialist care, monitor development, and access recommended therapies and support services. But research has also not established that starting these interventions in infancy improves long-term outcomes. How it Happened DMD is caused by pathogenic variants that result in a deficiency of dystrophin, a protein essential for muscle integrity. The disease primarily affects boys, causing loss of ambulation and eventually cardiac and respiratory complications. The interval between parents first noticing problems and a definitive diagnosis can stretch for years, said Scott Grosse, PhD, adjunct assistant professor of pediatrics at the University of Minnesota and senior author of a review on evidence backing expanding newborn screenings published recently in Pediatrics. Parents may raise concerns about a child’s trouble getting up from the floor or going up stairs, only to be told that the delay is normal. “That's why the term ‘diagnostic odyssey’ does appear to be appropriate in the case of Duchenne,” Grosse said. That lengthy search for answers is one reason clinicians and policymakers are reconsidering what newborn screening should accomplish. The screening “ allows families to gain access to the necessary specialists early on so a plan of care can be established to counsel, initiate treatment, and provide support over time ,” said Rachel Schrader, APRN, CPNP-PC, vice president of clinical care and education at Parent Project Muscular Dystrophy (PPMD). PPMD has been instrumental in the push for screening. The patient advocacy group, along with others, submitted in 2022 a nomination for the condition to be added to a federal list of recommended birth screenings that states cover. PPMD has received industry support for its newborn screening work, including from manufacturers with commercial or investigational DMD therapies. After the US Department of Health and Human Services added DMD to its recommended list in 2025, Florida and Texas passed laws mandating screening. Four other states, including Minnesota and New York, have also added the condition. Schrader said they are working with states on implementation and clinician education. But the moves come amid a changing treatment landscape. Care for the disorder once relied largely on corticosteroids and supportive therapies. Treatment options now include gene therapy, mutation-specific drugs, and medications designed to slow muscle degeneration. However, most are only approved starting when the child is a toddler, not in infancy. A review published in Pediatrics found no clear evidence that earlier initiation of DMD treatment reduces mortality or defers the loss of movement. Glucocorticoids are associated with delayed loss of ambulation in adults, but whether starting them in early childhood or infancy improves outcomes has not been established. Some clinicians now consider starting the drugs earlier than the traditional age of 4 years. However, the medications can cause weight gain, impaired growth, bone complications, and behavioral changes, which may deter some clinicians from prescribing them. Other InterventionsNewborn screening is often viewed as an inherently equitable public health intervention because it offers testing to every infant. But the expansion has renewed debate about what newborn screening should accomplish. Traditionally, the goal is to improve outcomes before symptoms of a condition ever present. But for DMD, the benefits “have to do with getting the patient identified early so that the family can access resources around that diagnosis,” such as neuromuscular neurologists and other supports, said Garey Noritz, MD, section chief of developmental and behavioral pediatrics at Nationwide Children’s Hospital in Columbus, Ohio. Noritz was involved in pilot initiatives to implement newborn screening. A child with DMD often presents with developmental differences involving language, cognition, behavior, and social-emotional skills. “We know that establishing care with expert providers and accessing early interventions, like speech and physical therapy, can support long term outcomes, as those delays are often present in early toddlerhood,” Schrader said. However, the 2026 evidence review found no studies demonstrating that starting nonpharmacologic interventions before symptoms appear improves outcomes compared with starting after a symptomatic diagnosis. “Some boys with Duchenne also have learning difficulties that may benefit from early recognition and services,” Kwon said. “But there is comparatively little treatment-oriented action to take during infancy.” Kwon said some parents of two children with DMD report that earlier diagnosis led to a younger sibling faring better than their older sibling. However, parents may report this because they spent more time navigating options and specialists for their older child. By the time they did the same for their younger child, care pathways were clearer. Determining whether newborn screening improves outcomes will require longitudinal study. Noritz said researchers already track patient information such as age at diagnosis, cardiac and lung function, mobility, and genetic variants through clinical registries such as MD STARnet. Researchers should also examine how early diagnosis affects families’ experiences, he said.For now, without evidence that earlier detection improves long-term outcomes, counseling is especially challenging, Kwon said. Rather than promising that early treatment will prevent serious harm, clinicians must help families understand a progressive disease and prepare for decisions that may not arise for years. As Kwon put it, “we’re focused on the scope of the future that they’re facing.” Grosse, Kwon, and Noritz reported no relevant financial relationships. Lara Salahi is a health journalist based in Boston.