Newborn Screening For Spinal Muscular Atrophy: Outcomes and Insights From A Single-Center Experience

Objectives: The advent of disease modifying therapies in the last decade has dramatically changed the field of spinal muscular atrophy (SMA). Herein, we report our experience with short-term outcomes of newborn screening (NBS) for SMA.

Methods: A total of ten patients identified by SMA newborn screening were included. Clinical variables, including demographic features, age at diagnosis, symptoms, SMN2 copy number, age at treatment onset, developmental stages, baseline/follow-up neurological examinations and standardized physiotherapeutic assessments were retrospectively analyzed.

Results: The median age of the patients at last visit was 9.5 months (2-17 months). The median age at diagnosis was 9 days (6-27 days). One patient had 1 SMN2 copy, 4 had 2 copies, 2 had 3, and 3 had more than 3 copies. One of the patients had an additional diagnosis of trisomy 21. Six patients had Nusinersen treatment. Nusinersen therapy was initiated at the age of 22-28 days in 4 patients with 2 SMN2 copies. Two patients with 3 SMN2 copies had treatment at 53 days of life and 10 months of age. In the follow-up, all the treated patients gained motor milestones and none of them developed respiratory/swallowing problems. Untreated patient with one SMN2 copy died at the age of 3 months.

Conclusion: Our results are consistent with previous reports of improved outcomes from early diagnosis and treatment. Long-term real-world outcome results and determination of disease modifying factors will improve our understanding of the disease. Benefits of early treatment underscores for the need for rapid referral to specialized neuromuscular centers.