Short-incubation mass spectrometry assay for lysosomal storage disorders in newborn and high-risk population screening

AbstractObjective: A modified method for screening of six lysosomal storage disorders (LSDs) by tandem mass spectrometry was presented.Methods: The enzyme activities for six LSDs (Gaucher, Pompe, Krabbe, Fabry, Niemann-Pick A/B and Mucopolysaccharidosis Type I) was measured by using ultra- HPLC and mass spectrometry. After overnight incubation of dried blood spots with three distinct reaction cocktails containing substrates and internal standards, reactions were stopped and online trapping was performed with ultra-HPLC preceding to mass spectrometry. Ultra-HPLC was equipped with online solid phase extraction and Hypersil Gold C8 analytical columns and coupled with TSQ Quantum Access Max mass spectrometry.Results: Activities of acid-s-glucocerebrosidase (ABG), acid glucosidase (GAA), galactocerebroside-s-galactosidase (GALC), acid-galactosidase A (GLA), acid sphingomyelinase (ASM), and α-L-iduronidase (IDU) were obtained from DBSs of patients and healthy individuals. The intraand inter-assay precisions were <20% (CV).Conclusion: Our modified method, needing less DBS punches and only three reaction coctails, with the online trapping methodology, accurately differentiates newborns with LSDs from healthy newborns.

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Biomarkers for Lysosomal Storage Disorders with an Emphasis on Mass Spectrometry

International Journal of Molecular Sciences ◽

10.3390/ijms21082704 ◽

2020 ◽

Vol 21 (8) ◽

pp. 2704 ◽

Cited By ~ 2

Author(s):

Ryuichi Mashima ◽

Torayuki Okuyama ◽

Mari Ohira

Keyword(s):

Mass Spectrometry ◽

Biomarker Discovery ◽

Short Review ◽

Lysosomal Storage Disorders ◽

Lysosomal Storage ◽

Niemann Pick Disease ◽

Clinical Diagnoses ◽

History Of ◽

Niemann Pick ◽

Storage Disorders

Lysosomal storage disorders (LSDs) are characterized by an accumulation of various substances, such as sphingolipids, mucopolysaccharides, and oligosaccharides. The LSD enzymes responsible for the catabolism are active at acidic pH in the lysosomal compartment. In addition to the classically established lysosomal degradation biochemistry, recent data have suggested that lysosome plays a key role in the autophagy where the fusion of autophagosome and lysosome facilitates the degradation of amino acids. A failure in the lysosomal function leads to a variety of manifestations, including neurovisceral disorders. While affected individuals appear to be normal at birth, they gradually become symptomatic in childhood. Biomarkers for each condition have been well-documented and their proper selection helps to perform accurate clinical diagnoses. Based on the natural history of disorders, it is now evident that the existing treatment becomes most effective when initiated during presymptomatic period. Neonatal screening provides such a platform for inborn error of metabolism in general and is now expanding to LSDs as well. These are implemented in some areas and countries, including Taiwan and the U.S. In this short review, we will discuss several issues on some selected biomarkers for LSDs involving Fabry, Niemann–Pick disease type C, mucopolysaccharidosis, and oligosaccharidosis, with a focus on mass spectrometry application to biomarker discovery and detection.

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