title: Improved analysis of C26:0-lysophosphatidylcholine in dried-blood spots via negative ion mode HPLC-ESI-MS/MS for X-linked adrenoleukodystrophy newborn screening.
abstract: BACKGROUND
  X-linked adrenoleukodystrophy (X-ALD) is the most common human peroxisomal disorder, and is caused by mutations in the peroxisomal transmembrane ALD protein (ALDP, ABCD1). The biochemical defect associated with X-ALD is an accumulation of very long-chain fatty acids (VLCFA, e.g. C24:0 and C26:0), which has been shown to result in the accumulation of C26:0-lysophosphatidylcholine (C26:0-LPC).
  
  
  METHODS
  We describe the analysis of C26:0-LPC in dried-blood spots (DBS) using a rapid (30 min) and simple extraction procedure, isocratic HPLC resolution of LPC, and structure-specific analysis via negative ion mode tandem mass spectrometry.
  
  
  RESULTS
  In putative normal DBS specimens from newborns (N=223) C26:0-LPC was 0.09±0.03 μmol/l whole blood, while in peroxisomal biogenesis disorder (including X-ALD) patients (N=28) C26:0-LPC was 1.13±0.67 μmol/l whole blood. Both multiple reaction monitoring and a neutral loss scan (225.1 Da) analysis of DBS were used to analyze LPC.
  
  
  CONCLUSIONS
  Compared to a previous report of C26:0-LPC analysis in DBS, the method described here is simpler, faster, and more structure-specific for LPC with C26:0 acyl chains.
authors.affiliation: Newborn Screening and Molecular Biology Branch, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. cph7@cdc.gov
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Haynes
authors.forename: Víctor R
authors.initials: VR
authors.lastname: De Jesús
mesh_terms: D000326:Adrenoleukodystrophy / Q000097:blood* / Q000175:diagnosis / Q000235:genetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D059788:Dried Blood Spot Testing / Q000379:methods; D006801:Humans; D007231:Infant, Newborn; D008244:Lysophosphatidylcholines / Q000097:blood*; D015997:Neonatal Screening; D018901:Peroxisomal Disorders / Q000097:blood*; D012016:Reference Values; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D008244:Lysophosphatidylcholines