title: Evaluation of plasma trace element and mineral status in children and adolescents with phenylketonuria using data from inductively-coupled-plasma atomic emission and mass spectrometric analysis.
abstract: BACKGROUND
  Phenylketonuria (PKU) is caused by a severe phenylalanine hydroxylase deficiency; the mainstay of treatment is a low-phenylalanine diet. A diet which is so restrictive is associated with a risk of nutritional deficiencies. We investigated plasma concentrations for 46 elements, including minerals and trace elements.
  
  
  METHODS
  We enrolled 20 children and adolescents with PKU and 20 matched controls. Multi-elementary quantification was carried out by solution-based inductively coupled plasma atomic emission spectroscopy (ICP-AES) and ICP mass spectrometry (ICP-MS).
  
  
  RESULTS
  With the exception of manganese and aluminium, no significant differences were found for element levels between PKU patients and controls. As a trend, manganese levels were lower in PKU patients than in control subjects (p < 0.05) but were within the reference range. There was a positive linear relationship between manganese and tyrosine levels in subjects with PKU (r(2) = 0.2295, p < 0.05). If detectable, potentially toxic elements were only identified in ultra-trace quantities in plasma samples of either group; aluminium levels were found to be slightly higher in PKU subjects than in controls (p < 0.01).
  
  
  CONCLUSIONS
  The combination of ICP-AES and ICP-MS data is a useful diagnostic tool for element quantification at a high analytical rate and for monitoring bio-element status, e.g. in patients on a restrictive diet.
authors.affiliation: National Centre for Inherited Metabolic Disorders, Children's University Hospital, Dublin, Ireland.
authors.forename: I
authors.initials: I
authors.lastname: Knerr
authors.forename: H
authors.initials: H
authors.lastname: Blessing
authors.forename: S
authors.initials: S
authors.lastname: Seyferth
authors.forename: R J
authors.initials: RJ
authors.lastname: Watling
authors.forename: M A
authors.initials: MA
authors.lastname: Chaudhri
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004032:Diet; D002149:Energy Intake; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D009752:Nutritional Status; D010649:Phenylalanine / Q000008:administration & dosage / Q000097:blood; D010661:Phenylketonurias / Q000097:blood*; D012016:Reference Values; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014131:Trace Elements / Q000097:blood*
chemical_list: D014131:Trace Elements; D010649:Phenylalanine