Clinical Experience of Timing Treatment in Newborns with Spinal Muscular Atrophy: A Call for Standardized Screening Practices in Italy

TL;DR

This study highlights the importance of early diagnosis and treatment for spinal muscular atrophy in newborns through screening and pre-symptomatic intervention.

Contribution

The paper emphasizes the need for standardized newborn screening practices in Italy to enable timely SMA treatment.

Findings

Thirteen infants tested positive for SMA among 62,801 screened in the Campania region.

Pre-symptomatic treatment improved motor outcomes, with some patients walking independently within two years.

SMN2 copy numbers varied among patients, influencing treatment outcomes.

Abstract

Spinal muscular atrophy (SMA) is a rare neuromuscular disorder causing progressive muscle weakness. Severe SMA forms are typically observed up to six months postnatally. Disease-modifying therapies provide significant benefits, making newborn screening (NBS) essential for timely diagnosis and treatment initiation. The NBS programme evaluated infants born between April 2023 and October 2024 in the Campania region, Italy. DNA was amplified to detect homozygous deletion of the SMN1 gene by RT-PCR and SMN2 copy number using multiplex ligation-dependent probe amplification. Following treatment, motor functions were assessed using CHOP-INTEND and Bayley III scales. Among 62,801 infants screened for SMA, thirteen (11 females, 2 males) tested positive. The distribution of SMN2 copy numbers was as follows: eight patients had two copies, one patient had three, and four patients had four copies. One year after treatment, motor outcome data were available for four of the eight patients with two SMN2 copies. Among these patients, one achieved the milestones of walking without support, and three were standing with support. At 24 months, three of these patients were walking independently. Pre-symptomatic treatment markedly improves motor function development. This underscores the urgent need for large-scale newborn screening to prevent diagnostic delays and ensure timely, effective therapy. Validated care protocols must be established to facilitate early diagnosis and intervention.

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