Metabolomic screening in neonates

Abstract

Surveillance for inbornerrorsof metabolism(IEMs)typically relies on three programs: universal neonatal screening, targeted screening of children and adults who present with symptoms, and postmortem screening of sudden unexpected deaths. Tandem mass spectrometryisnow akeytechnologyinalltheseareas. Allneonates in Australasia are screened for approximately 24 IEMs with dried blood spot samples being analysed for a panel of amino acids and acyl carnitines. Some metabolites have relatively poor positive predictive value and second tier tests for more specific metabolites can be used to improve this situation. Earlier diagnosis has resulted in improved treatment and outcomes and some maternal deficiencies are detected via testing of the baby. Some IEMs can cause death before the neonatal screening sample is collected but these disorders can be diagnosed from dried blood spots collected post-mortem. Many more IEMs can be diagnosed through urine screening of symptomatic patients and a metabolomics platform has been developed to target >100 biomarkers. New biomarkers are easily added to the panel as new disorders are discovered. This platform has streamlined laboratory procedures and improved the overall performance of Victoria’s urine screening program.