A highly multiplexed biochemical assay for analytes in dried blood spots: application to newborn screening and diagnosis of lysosomal storage disorders and other inborn errors of metabolism.

To develop a multiplexed assay for the newborn screening of lysosomal storage disorders and additional inborn errors in a flexible, comprehensive, and affordable manner to keep up with the expansion of the newborn screening panel. Ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was chosen as the detection platform for its superiority compared to traditional flow-injection MS/MS. A high-throughput, 18-plex UPLC-MS/MS assay was developed for screening purposes with a sample turnaround time of 2.7 minutes. The assay was consolidated such that only four dried blood spot punches were required, and it displayed good precision and reproducibility. We report a highly multiplexed UPLC-MS/MS assay that is appropriate for the newborn screening of 15 lysosomal storage diseases and 3 additional inborn errors. It can be further expanded to include additional conditions for which presymptomatic diagnosis may facilitate optimum treatment outcome.