Evidence gaps hindering implementation of newborn screening for galactosemia

Background

Variability in newborn screening for classic galactosemia (GALT) across countries reflects important evidence gaps that challenge consistent and equitable implementation. Robust evidence is required to support decisions on screening effectiveness and safety.

Methods

A systematic review of the literature was conducted to assess the clinical effectiveness and safety of newborn screening for galactosemia compared with no screening. Searches included systematic reviews, health technology assessments, and primary studies (2019–2026). Study selection followed PRISMA guidelines. Evidence was synthesised using an Evidence-to-Decision framework. A national survey of screening programmes was also performed.

Results

Three critical evidence gaps represent key challenges for implementation. First, the early age of clinical onset—often within the first week of life—may precede the availability of screening results, limiting timely intervention. Second, heterogeneous screening strategies, including variability in biomarkers and cut-off thresholds, lead to uncertainty in test performance and hinder comparability across programmes. Third, evidence on the benefits of presymptomatic treatment is limited and inconclusive, with no robust data demonstrating improved long-term outcomes.

Conclusions

Key uncertainties in timing, test performance and outcomes limit conclusions on the effectiveness and safety of newborn screening for GALT. Addressing these challenges is essential to support consistent and equitable implementation across health systems. Strengthening evidence on long-term benefits and promoting standardisation of screening protocols should be prioritised.

Key messages

• Key evidence gaps in timing, testing and outcomes challenge implementation of galactosemia screening.

• Stronger evidence and standardisation are needed for consistent and equitable screening decisions.