Pilot Study on Newborn Screening for Spinal Muscular Atrophy

Area of Science:

• Medical Genetics
• Public Health
• Neonatology

Background:

• Newborn screening (NBS) in Portugal is vital for early detection and treatment of disorders.
• Spinal muscular atrophy (SMA) is a severe neuromuscular disorder affecting motor neurons, with an incidence of 1 in 6,000-11,800 live births.
• A pilot NBS study is evaluating SMA screening feasibility, sensitivity, and specificity in Portugal.

Purpose of the Study:

• To assess the feasibility of implementing spinal muscular atrophy (SMA) screening within Portugal's existing newborn screening (NBS) program.
• To determine the sensitivity and specificity of SMA detection in a large newborn cohort.
• To support the recommendation for including SMA in national NBS programs.

Main Methods:

• Analysis of 25,000 newborn blood samples for SMA.
• Qualitative detection of SMN1 gene exon 7 deletion using real-time PCR (Eonis SMN1, TREC, and KREC kit).
• Confirmation of positive cases via specialized clinical and reference laboratory analysis.

Main Results:

• Two out of 25,000 newborns screened were diagnosed with SMA due to SMN1 deletion.
• Positive SMA cases were referred for confirmatory testing, including SMN2 copy number determination.
• The pilot study provides data on the prevalence and detection of SMA in the Portuguese newborn population.

Conclusions:

• Early diagnosis and pre-symptomatic treatment are critical for effective spinal muscular atrophy (SMA) intervention.
• Newborn screening (NBS) for SMA is strongly recommended given the availability of targeted therapies.
• Inclusion of SMA screening in newborn programs is a global trend supported by this study's findings.