A Voluntary Statewide Newborn Screening Pilot for Spinal Muscular Atrophy: Results from Early Check.

Area of Science:

• Genetics and Genetic Disorders
• Newborn Screening
• Neuromuscular Diseases

Background:

• North Carolina implemented voluntary newborn screening (NBS) for spinal muscular atrophy (SMA) via the Early Check (EC) research study prior to statewide expansion.
• The EC study aimed to gather data on the feasibility and effectiveness of SMA screening in newborns.

Purpose of the Study:

• To describe the experience and outcomes of voluntary SMA NBS through the EC research study from October 2018 to December 2020.
• To evaluate the timing of screening for prenatally and postnatally enrolled infants and identify reasons for delays.
• To assess the performance of the SMA quantitative PCR (q-PCR) screening assay.

Main Methods:

• Enrolled 12,065 newborns for voluntary screening.
• Utilized a quantitative PCR (q-PCR) assay to screen for SMA by analyzing SMN1 and SMN2 gene copy numbers.
• Compared screening and reporting times for infants enrolled prenatally versus postnatally.

Main Results:

• Identified one newborn with a confirmed diagnosis of SMA (0 copies of SMN1, 2 copies of SMN2).
• Detected one false positive result, potentially due to an unrelated blood disorder.
• Prenatal enrollment resulted in faster return of results (median 13 days) compared to postnatal enrollment (median 21 days), both within a clinically relevant timeframe for early treatment.

Conclusions:

• The EC pilot project successfully demonstrated the capability to screen for SMA in newborns, identifying a case requiring early intervention.
• The SMA q-PCR screening method proved robust and reliable.
• The findings provided valuable insights for the upcoming statewide NBS program for SMA.