title: Diagnosing inborn errors of lipid metabolism with proton nuclear magnetic resonance spectroscopy.
abstract: BACKGROUND
  Many severe diseases are caused by defects in lipid metabolism. As a result, patients often accumulate unusual lipids in their blood and tissues, and proper identification of these lipids is essential for correct diagnosis. In this study, we investigated the potential use of proton nuclear magnetic resonance (1H-NMR) spectroscopy to simultaneously identify and quantify (un)usual lipids present in the blood of patients with different inborn errors of lipid metabolism.
  
  
  METHODS
  We extracted blood plasma or serum lipids in chloroform-methanol (2:1 by volume). After addition of the nonvolatile chemical shift and concentration reference compound octamethylcyclotetrasiloxane, we performed 1H-NMR measurements on a 500-MHz spectrometer. Assignments were based on the literature, computer simulations, and reference spectra of relevant authentic standards.
  
  
  RESULTS
  Spectra of normal plasma samples allowed the identification of 9 lipid species. We found good correlation between conventional methods and 1H-NMR for cholesterol and triglyceride concentrations. We also investigated 4 inborn errors of lipid metabolism (3 in sterol metabolism and 1 in fatty acid metabolism). NMR analysis led to a correct diagnosis for all 4 diseases, whereas the concentration of the diagnostic metabolite could be determined for 3.
  
  
  CONCLUSIONS
  1H-NMR spectroscopy of blood plasma or serum lipid extracts can be used to accurately identify and quantify lipids. The method can also identify unusual lipids in the blood of patients with inborn errors of lipid metabolism. This technique may therefore be applicable in clinical diagnosis and follow-up.
authors.affiliation: Laboratory of Pediatrics and Neurology and Department of Pediatric Neurology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Marlies
authors.initials: M
authors.lastname: Oostendorp
authors.forename: Udo F H
authors.initials: UF
authors.lastname: Engelke
authors.forename: Michèl A A P
authors.initials: MA
authors.lastname: Willemsen
authors.forename: Ron A
authors.initials: RA
authors.lastname: Wevers
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D007223:Infant; D008052:Lipid Metabolism, Inborn Errors / Q000175:diagnosis*; D008055:Lipids / Q000097:blood; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D011522:Protons; D012016:Reference Values; D012035:Refsum Disease / Q000175:diagnosis; D012855:Sitosterols / Q000378:metabolism; D019082:Smith-Lemli-Opitz Syndrome / Q000175:diagnosis; D019294:Xanthomatosis, Cerebrotendinous / Q000175:diagnosis
chemical_list: D008055:Lipids; D011522:Protons; D012855:Sitosterols