title: Transferrin variants: pitfalls in the diagnostics of Congenital disorders of glycosylation.
abstract: OBJECTIVE
  Transferrin variants can hinder the diagnostic process in cases of suspected Congenital disorders of glycosylation which affect N-Glycosylation. In addition they can impair the use of Carbohydrate deficient Transferrin as a biomarker for chronic alcohol abuse, in which Asialo-Transferrin and Disialo-Transferrin are increased. We present a novel transferrin variant as well as an overview of transferrin mutations found at our laboratory.
  
  
  METHODS
  Blood samples from patients with suspected CDG were analyzed using the standard diagnostic procedures of Isoelectric focusing and High-performance liquid chromatography as well as the additional procedures of neuraminidase digestion of glycans and Electrospray ionization time-of-flight mass spectrometry (ESI-TOF MS).
  
  
  RESULTS
  Four known and one previously unreported transferrin variants were identified. Neuraminidase digestion and ESI-TOF MS revealed changes in charge of the transferrin molecules while the glycosylation status was found to be normal.
  
  
  CONCLUSIONS
  Transferrin variants are pitfalls in the diagnostics of CDG. The found variants change the charge of the transferrin molecule, thus affecting the standard diagnostic procedures. Neuraminidase digestion as well as ESI-TOF MS can identify variants and mutations in a laboratory context.
authors.affiliation: Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Albert Schweitzer Campus 1, Gebäude A 1, 48149 Münster, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Zühlsdorf
authors.affiliation: Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Albert Schweitzer Campus 1, Gebäude A 1, 48149 Münster, Germany.
authors.forename: Julien Heinrich
authors.initials: JH
authors.lastname: Park
authors.affiliation: Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka University, 840 Murodo-cho, Izumi, Osaka 594-1101, Japan.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Wada
authors.affiliation: Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Albert Schweitzer Campus 1, Gebäude A 1, 48149 Münster, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Rust
authors.affiliation: Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Albert Schweitzer Campus 1, Gebäude A 1, 48149 Münster, Germany.
authors.forename: Janine
authors.initials: J
authors.lastname: Reunert
authors.affiliation: Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Albert Schweitzer Campus 1, Gebäude A 1, 48149 Münster, Germany.
authors.forename: Ingrid
authors.initials: I
authors.lastname: DuChesne
authors.affiliation: Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Albert Schweitzer Campus 1, Gebäude A 1, 48149 Münster, Germany.
authors.forename: Marianne
authors.initials: M
authors.lastname: Grüneberg
authors.affiliation: Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Albert Schweitzer Campus 1, Gebäude A 1, 48149 Münster, Germany. Electronic address: marquat@uni-muenster.de.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Marquardt
mesh_terms: D002851:Chromatography, High Pressure Liquid; D018981:Congenital Disorders of Glycosylation / Q000175:diagnosis* / Q000235:genetics*; D006801:Humans; D007525:Isoelectric Focusing; D009154:Mutation / Q000235:genetics*; D021241:Spectrometry, Mass, Electrospray Ionization; D014168:Transferrin / Q000235:genetics*
chemical_list: D014168:Transferrin
keywords: Biomarker; Carbohydrate deficient transferrin; Congenital disorders of glycosylation; Glycosylation; High-performance liquid chromatography; Isoelectric focusing; Mass spectrometry; Mutation; Neuraminidase; Transferrin