Spinal Muscular Atrophy Treatments, Newborn Screening, and the Creation of a Neurogenetics Urgency

Abstract

Spinal muscular atrophy (SMA) is a progressive neuromuscular disorder characterized by loss of motor neurons leading to muscle weakness and atrophy. The United States' Food and Drug Administration's (FDA) approval of nusinersen, onasemnogene abeparvovec, and risdiplam for SMA has challenged existing treatment paradigms with multiple treatment options, a new natural history of the disease, and an emerging understanding of the importance of early and pre-symptomatic treatment. The profound impact of early, pre-symptomatic treatment has led to the creation of a neurogenetics urgency for newly identified patients with SMA, a novel problem for neurologists more accustomed to a more methodical approach to diagnosis and care. Implementation of newborn screening programs has helped facilitate early diagnosis and treatment, but challenges remain in overcoming administrative and procedural hurdles that can lead to treatment delays. Herein I discuss 2 cases that highlight the importance of early treatment, as well as gaps in our understanding of the progression of SMA in pre-symptomatic infants.