Multiplex Enzymatic Assay for Newborn Screening of Mucopolysaccharidoses (type II, IIIB, IVA, VI, VII) and Neuronal Ceroid Lipofuscinosis II

摘要

New reagent (C6) for TPP1 has a lower initial conversion rate as a substrate, the product and int. std. have better sensitivity and better extraction efficiency than C3 version. The assay conditions were optimized for all 6 lysosomal enzymes and used one-step ex-traction as simplified sample work-up, reducing the liquid-transfer steps. The Isocratic LC-MS method was able to separate each pair of substrate and their enzymatic products, eliminating the interferences caused by thermal breakdown of sub-strates in the ESI source. Simultaneous (6-plex) detection of enzyme activities in dried blood spots for the early detection of MPS II, IIIB, IVA, VI, VII and NCL-II affected newborns was validated. The fast 2 min/sample efficiency allows high throughput analysis and thus meets the time constraints of a neonatal screening lab.