title: Newborn screening for lysosomal storage diseases.
abstract: BACKGROUND
  There is worldwide interest in newborn screening for lysosomal storage diseases because of the development of treatment options that give better results when carried out early in life. Screens with high differentiation between affected and nonaffected individuals are critical because of the large number of potential false positives.
  
  
  BACKGROUND
  This review summarizes 3 screening methods: (a) direct assay of enzymatic activities using tandem mass spectrometry or fluorometry, (b) immunocapture-based measurement of lysosomal enzyme abundance, and (c) measurement of biomarkers. Assay performance is compared on the basis of small-scale studies as well as on large-scale pilot studies of mass spectrometric and fluorometric screens.
  
  
  CONCLUSIONS
  Tandem mass spectrometry and fluorometry techniques for direct assay of lysosomal enzymatic activity in dried blood spots have emerged as the most studied approaches. Comparative mass spectrometry vs fluorometry studies show that the former better differentiates between nonaffected vs affected individuals. This in turn leads to a manageable number of screen positives that can be further evaluated with second-tier methods.
authors.affiliation: Department of Chemistry, Biochemistry, and gelb@chem.washington.edu.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Gelb
authors.affiliation: Pediatrics, University of Washington, Seattle, WA.
authors.forename: C Ronald
authors.initials: CR
authors.lastname: Scott
authors.affiliation: Department of Chemistry.
authors.forename: Frantisek
authors.initials: F
authors.lastname: Turecek
mesh_terms: D059788:Dried Blood Spot Testing / Q000379:methods; D057075:Enzyme Assays / Q000379:methods; D005470:Fluorometry / Q000379:methods; D006801:Humans; D007158:Immunologic Techniques / Q000379:methods; D007231:Infant, Newborn; D016464:Lysosomal Storage Diseases / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology*; D015997:Neonatal Screening / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods