Modern medical laboratories employ, depending on their analytical repertoire, an array of analytical techniques including gas chromatography-mass spectrometry (GC-MS), high-pressure liquid chromatography-mass spectrometry (HPLC-MS), liquid chromatography-mass spectrometry (LC-MS), or electrospray tandem mass spectrometry (ESI-MS/MS). In this context, MS is typically used for the analysis of small molecules for the diagnosis of inborn errors of metabolism (IEM), endocrine disorders, in toxicology, and pharmacology. The application of ESI-MS/MS allows the identification and quantification of individual oligosaccharides for the diagnosis of glycoproteinoses (oligosaccharidurias) such as GM1 gangliosidosis, GM2 gangliosidosis, sialic acid storage disorder, sialidase/neuraminidase deficiency, galactosialidosis, I-cell disease, fucosidosis, and Pompe and Gaucher diseases. This method is adapted to high-throughput use allowing the application to management follow-up and eventually newborn screening for this group of disorders. A direct multiplex assay of lysosomal enzymes in dried blood spots is developed for newborn screening. This approach is based on the incubation of dried blood spots at 37°C overnight with the appropriate substrates and stable isotopically labeled internal standards.
ASJC Scopus subject areas