Julien H Park1, Andrea Zühlsdorf1, Yoshinao Wada2, Claudia Roll3, Stephan Rust4, Ingrid Du Chesne1, Marianne Grüneberg1, Janine Reunert1, Thorsten Marquardt5. 1. Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Münster, Germany. 2. Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka University, Osaka, Japan. 3. Vestische Kinder- und Jugendklinik, Universität Witten/Herdecke, Datteln, Germany. 4. Leibniz-Institut für Arterioskleroseforschung, Münster, Germany. 5. Universitätsklinikum Münster, Klinik und Poliklinik für Kinder- und Jugendmedizin - Allgemeine Pädiatrie, Münster, Germany. Electronic address: marquat@uni-muenster.de.
Abstract
BACKGROUND: The analysis of serum transferrin either by high-performance liquid chromatography (HPLC) or isoelectric focusing (IEF) is the standard diagnostic procedure in patients with the suspicion of a congenital disorder of glycosylation (CDG). Carbohydrate-deficient transferrin (CDT) is also analysed in monitoring programmes in cases of alcohol abuse. We report a novel transferrin variant that impairs the analysis using conventional methods and propose alternative forms of analysis. METHODS: Transferrin samples were analysed using HPLC, immunoprecipitation followed by SDS-PAGE and IEF. Neuraminidase treatment followed by conventional IEF and electrospray ionization time of flight mass spectrometry (ESI-TOF MS) were applied before sequencing of the transferrin gene was performed. RESULTS: The novel transferrin variant E592A, found both in homozygous and heterozygous form, causes an altered charge of the transferrin molecule, which changes the results of IEF and HPLC and mimics an increase in trisialo-transferrin. The change in charge can be detected either by neuraminidase digestion followed by IEF or by ESI-TOF MS. CONCLUSION: Conventional diagnostic methods for CDG are hindered by the novel transferrin E592A. Neuraminidase treatment followed by IEF and ESI-TOF MS can identify the mutation. The mutation appears to be functionally normal.
BACKGROUND: The analysis of serum transferrin either by high-performance liquid chromatography (HPLC) or isoelectric focusing (IEF) is the standard diagnostic procedure in patients with the suspicion of a congenital disorder of glycosylation (CDG). Carbohydrate-deficient transferrin (CDT) is also analysed in monitoring programmes in cases of alcohol abuse. We report a novel transferrin variant that impairs the analysis using conventional methods and propose alternative forms of analysis. METHODS:Transferrin samples were analysed using HPLC, immunoprecipitation followed by SDS-PAGE and IEF. Neuraminidase treatment followed by conventional IEF and electrospray ionization time of flight mass spectrometry (ESI-TOF MS) were applied before sequencing of the transferrin gene was performed. RESULTS: The novel transferrin variant E592A, found both in homozygous and heterozygous form, causes an altered charge of the transferrin molecule, which changes the results of IEF and HPLC and mimics an increase in trisialo-transferrin. The change in charge can be detected either by neuraminidase digestion followed by IEF or by ESI-TOF MS. CONCLUSION: Conventional diagnostic methods for CDG are hindered by the novel transferrinE592A. Neuraminidase treatment followed by IEF and ESI-TOF MS can identify the mutation. The mutation appears to be functionally normal.
Authors: Julien H Park; Max Hogrebe; Marianne Grüneberg; Ingrid DuChesne; Ava L von der Heiden; Janine Reunert; Karl P Schlingmann; Kym M Boycott; Chandree L Beaulieu; Aziz A Mhanni; A Micheil Innes; Konstanze Hörtnagel; Saskia Biskup; Eva M Gleixner; Gerhard Kurlemann; Barbara Fiedler; Heymut Omran; Frank Rutsch; Yoshinao Wada; Konstantinos Tsiakas; René Santer; Daniel W Nebert; Stephan Rust; Thorsten Marquardt Journal: Am J Hum Genet Date: 2015-12-03 Impact factor: 11.025
Authors: Kristine Nolting; Julien H Park; Laura C Tegtmeyer; Andrea Zühlsdorf; Marianne Grüneberg; Stephan Rust; Janine Reunert; Ingrid Du Chesne; Volker Debus; Eric Schulze-Bahr; Robert C Baxter; Yoshinao Wada; Christian Thiel; Emile van Schaftingen; Ralph Fingerhut; Thorsten Marquardt Journal: Mol Genet Metab Rep Date: 2017-07-31