Presymptomatic spinal muscular atrophy: a cautionary approach to the proposed new terminology

A state-of-the-art review of registries in spinal muscular atrophy: A valuable resource for clinical research

Since 2016/17, three disease modifying therapies for spinal muscular atrophy (SMA) have been translated into clinical practice. This has driven the implementation of newborn screening to transform health outcomes and clinical practice. SMA registries have provided important sources of data on the evolution of novel phenotypes within the therapeutic era, treatment patterns, epidemiology, genotype-phenotype correlations, care and lived experiences of people living with SMA, to enrich knowledge and learnings of the condition in this changed landscape. In this state-of-the-art review, we consider the utility and outcomes of SMA registries and evaluate their role and importance. In 2024 there are more than 35 national registries cataloguing over 8000 individuals with SMA. Additional registries are operated by advocacy groups and pharmaceutical companies, compiling data for more than 10,000 individuals with this condition. This review highlights the essential role of registries in supporting clinical trial recruitment, defining the changing incidence and prevalence of SMA in an age of reproductive carrier and newborn screening, establishing natural history data, contributing to post market drug surveillance, assessing real world clinical and cost effectiveness and capturing patient-reported outcome measures (PROMS) and experience measures (PREMS). Whilst their utility is broad, barriers to effective data curation and management are evaluated including challenges of data curation and fragmentation, quality and sharing, alongside resource constraints and sustainability. Strategies to enhance the value of registries include the imperative to collaborate across clinical research networks and the value of interoperability, enabled by standardization of data collection and entry, sharing procedures and public and patient involvement. As new phenotypes and unmet needs emerge in the post therapeutic era, registries remain central tools in generating new insights now and into the future and are poised to respond meaningfully to the priorities of individuals living with SMA.

Spinal Muscular Atrophy Update in Best Practices: Recommendations for Diagnosis Considerations

Background and Objectives

Spinal muscular atrophy (SMA) is an autosomal recessive progressive neurodegenerative primary motor neuron disorder caused by biallelic variants of the survival motor neuron 1 (SMN1) gene. The most recent SMA best practice recommendations were published in 2018 shortly after the approval of the first SMN-enhancing treatment. The availability of disease-modifying therapies for 5q SMA and implementation of SMA newborn screening (NBS) has led to urgency to update the SMA best practice recommendations for diagnosis and to reevaluate the current classification of SMA. In addition, the availability of disease-modifying therapies has opened the door to explore improved diagnosis of adult-onset SMA.

Methods

A systematic literature review was conducted on SMA NBS. An SMA working group of American and European health care providers developed recommendations through a modified Delphi technique with serial surveys and virtual meeting feedback on SMA diagnosis to fill information gaps for topics with limited evidence. A community working group of an individual with SMA and caregivers provided insight and perspective on SMA diagnosis and support through a virtual meeting to guide recommendations.

Results

The health care provider working group achieved consensus that SMA NBS is essential to include in the updated best practice for SMA diagnosis (100%). Recommendations for the following are described: characterizing NBS-identified infants before treatment; minimum recommendations for starting or offering SMA NBS in a state or country; recommendations for activities and services to be provided by an SMA specialty care center accepting SMA NBS referrals; and recommendations for partnership with individuals with SMA and caregivers to support NBS-identified infants and their caregivers. Limited data are available to advance efficient diagnosis of adult-onset SMA.

Discussion

Updating best practice recommendations for SMA diagnosis to include SMA NBS implementation is essential to advancing care for individuals with SMA. In addition to testing, processes for the efficient management of positive newborn screen with access to knowledgeable and skilled health care providers and access to treatment options is critical to successful early diagnosis. Additional evidence is required to improve adult-onset SMA diagnosis.

Decision-making and challenges within the evolving treatment algorithm in spinal muscular atrophy: a clinical perspective

INTRODUCTION

The clinical application of disease modifying therapies has dramatically changed the paradigm of the management of people with spinal muscular atrophy (SMA), from sole reliance on symptomatic care directed toward the downstream consequences of muscle weakness, to proactive intervention and even preventative care.

AREAS COVERED

In this perspective, the authors evaluate the contemporary therapeutic landscape of SMA and discuss the evolution of novel phenotypes and the treatment algorithm, including the key factors that define individual treatment choice and treatment response. The benefits achieved by early diagnosis and treatment through newborn screening are highlighted, alongside an appraisal of emerging prognostic methods and classification frameworks to inform clinicians, patients, and families about disease course, manage expectations, and improve care planning. A future perspective of unmet needs and challenges is provided, emphasizing the key role of research.

EXPERT OPINION

SMN-augmenting therapies have improved health outcomes for people with SMA and powered the practice of personalized medicine. Within this new proactive diagnostic and treatment paradigm, new phenotypes and different disease trajectories are emerging. Ongoing collaborative research efforts to understand the biology of SMA and define optimal response are critical to refining future approaches.