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Georg F Hoffmann - One of the best experts on this subject based on the ideXlab platform.
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Extended diagnosis of purine and pyrimidine disorders from urine: LC MS/MS assay development and clinical validation - Fig 3
2019Co-Authors: Péter Monostori, Georg F Hoffmann, Glynis Klinke, Jana Hauke, Sylvia Richter, Jörgen Bierau, Sven F. Garbade, Claus-dieter Langhans, Dorothea Haas, Jürgen G. OkunAbstract:LC-MS/MS chromatograms of A: the Cal06 calibrator (16 μM) and urine specimens from B: a healthy proband; C: a patient with ADSL deficiency; D: a patient with HGPRT deficiency; E: a patient with UPB1 deficiency; and F: a patient with APRT deficiency. All intensities (Y-axes) have been normalized to 1.5*108 cps for better comparability and have been plotted against retention time (X-axes). Analytes have been numbered as follows: 1. URA; 2. DHU; 3. Thy; 4. DHT; 5. BUP; 6. ADN; 7. Hypo; 8. ALLOP; 9. BUIB; 10. Xan; 11. DHA; 12. dAdo; 13. AICAr; 14. ADS; 15. HMU; 16. Oro; 17. dUrd; 18. THD; 19. PSU; 20. dIno; 21. dGui; 22. Ino; 23. Guo; 24. Ord; 25. SAICAr; 26. SAdo. The ISs have been marked by an asterisk (*) after the number of the respective unlabeled analyte. Note that guanosine-IS has been measured in both ESI+ and ESI-. ADSL: Adenylosuccinate lyase deficiency; HGPRT: Hypoxanthine-guanine phosphoribosyltransferase deficiency; UPB1: Beta-Ureidopropionase deficiency; APRT: Adenine phosphoribosyltransferase deficiency. Further abbreviations are provided in the List of Abbreviations Section. Chromatograms were generated by MassLynx 4.1 (Waters, Milford, MA, USA) and modified using Inkscape 0.91pre4 (Open Source Software licensed under the GNU General Public License).
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comprehensive analysis of pyrimidine metabolism in 450 children with unspecific neurological symptoms using high pressure liquid chromatography electrospray ionization tandem mass spectrometry
Journal of Inherited Metabolic Disease, 2005Co-Authors: Christiane Schmidt, Ute Hofmann, Dirk Kohlmuller, Thomas E Murdter, Ulrich M Zanger, Matthias Schwab, Georg F HoffmannAbstract:To evaluate the significance of inborn metabolic disorders of the pyrimidine degradation pathway, 450 children with unspecific neurological symptoms were comprehensively studied; 200 healthy children were recruited as controls. Uracil and thymine as well as their degradation products in urine were determined with an improved method based on reversed-phase HPLC coupled with electrospray ionization tandem mass spectrometry and detection by multiple-reaction monitoring using stable-isotope-labelled reference compounds as internal standards. From the results of the control group we established age-related reference ranges of all pyrimidine degradation products. In the patient group, two children with dihydropyrimidine dehydrogenase (DPYD) deficiency were identified; one of these was homozygous for the exon 14-skipping mutation of the DPYD gene. In addition, two patients with high uracil, dihydrouracil and beta-ureidopropionate were found to have ornithine transcarbamylase deficiency. In the urine of 9 patients, beta-alanine was markedly elevated owing to treatment with vigabatrin, an irreversible inhibitor of GABA transaminase, which interferes with beta-alanine breakdown. Four patients had exclusively high levels of beta-aminoisobutyrate (beta-AIB) due to a low activity of the D-beta-AIB-pyruvate aminotransferase, probably without clinical significance. In conclusion, quantitative investigation of pyrimidine metabolites in children with unexplained neurological symptoms, particularly epileptic seizures with or without psychomotor retardation, can be recommended as a helpful tool for diagnosis in clinical practice. Sensitive methods and age-related reference ranges enable the detection of partial enzyme deficiencies.
Christiane Schmidt - One of the best experts on this subject based on the ideXlab platform.
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comprehensive analysis of pyrimidine metabolism in 450 children with unspecific neurological symptoms using high pressure liquid chromatography electrospray ionization tandem mass spectrometry
Journal of Inherited Metabolic Disease, 2005Co-Authors: Christiane Schmidt, Ute Hofmann, Dirk Kohlmuller, Thomas E Murdter, Ulrich M Zanger, Matthias Schwab, Georg F HoffmannAbstract:To evaluate the significance of inborn metabolic disorders of the pyrimidine degradation pathway, 450 children with unspecific neurological symptoms were comprehensively studied; 200 healthy children were recruited as controls. Uracil and thymine as well as their degradation products in urine were determined with an improved method based on reversed-phase HPLC coupled with electrospray ionization tandem mass spectrometry and detection by multiple-reaction monitoring using stable-isotope-labelled reference compounds as internal standards. From the results of the control group we established age-related reference ranges of all pyrimidine degradation products. In the patient group, two children with dihydropyrimidine dehydrogenase (DPYD) deficiency were identified; one of these was homozygous for the exon 14-skipping mutation of the DPYD gene. In addition, two patients with high uracil, dihydrouracil and beta-ureidopropionate were found to have ornithine transcarbamylase deficiency. In the urine of 9 patients, beta-alanine was markedly elevated owing to treatment with vigabatrin, an irreversible inhibitor of GABA transaminase, which interferes with beta-alanine breakdown. Four patients had exclusively high levels of beta-aminoisobutyrate (beta-AIB) due to a low activity of the D-beta-AIB-pyruvate aminotransferase, probably without clinical significance. In conclusion, quantitative investigation of pyrimidine metabolites in children with unexplained neurological symptoms, particularly epileptic seizures with or without psychomotor retardation, can be recommended as a helpful tool for diagnosis in clinical practice. Sensitive methods and age-related reference ranges enable the detection of partial enzyme deficiencies.
Thomas E Murdter - One of the best experts on this subject based on the ideXlab platform.
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comprehensive analysis of pyrimidine metabolism in 450 children with unspecific neurological symptoms using high pressure liquid chromatography electrospray ionization tandem mass spectrometry
Journal of Inherited Metabolic Disease, 2005Co-Authors: Christiane Schmidt, Ute Hofmann, Dirk Kohlmuller, Thomas E Murdter, Ulrich M Zanger, Matthias Schwab, Georg F HoffmannAbstract:To evaluate the significance of inborn metabolic disorders of the pyrimidine degradation pathway, 450 children with unspecific neurological symptoms were comprehensively studied; 200 healthy children were recruited as controls. Uracil and thymine as well as their degradation products in urine were determined with an improved method based on reversed-phase HPLC coupled with electrospray ionization tandem mass spectrometry and detection by multiple-reaction monitoring using stable-isotope-labelled reference compounds as internal standards. From the results of the control group we established age-related reference ranges of all pyrimidine degradation products. In the patient group, two children with dihydropyrimidine dehydrogenase (DPYD) deficiency were identified; one of these was homozygous for the exon 14-skipping mutation of the DPYD gene. In addition, two patients with high uracil, dihydrouracil and beta-ureidopropionate were found to have ornithine transcarbamylase deficiency. In the urine of 9 patients, beta-alanine was markedly elevated owing to treatment with vigabatrin, an irreversible inhibitor of GABA transaminase, which interferes with beta-alanine breakdown. Four patients had exclusively high levels of beta-aminoisobutyrate (beta-AIB) due to a low activity of the D-beta-AIB-pyruvate aminotransferase, probably without clinical significance. In conclusion, quantitative investigation of pyrimidine metabolites in children with unexplained neurological symptoms, particularly epileptic seizures with or without psychomotor retardation, can be recommended as a helpful tool for diagnosis in clinical practice. Sensitive methods and age-related reference ranges enable the detection of partial enzyme deficiencies.
Ute Hofmann - One of the best experts on this subject based on the ideXlab platform.
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comprehensive analysis of pyrimidine metabolism in 450 children with unspecific neurological symptoms using high pressure liquid chromatography electrospray ionization tandem mass spectrometry
Journal of Inherited Metabolic Disease, 2005Co-Authors: Christiane Schmidt, Ute Hofmann, Dirk Kohlmuller, Thomas E Murdter, Ulrich M Zanger, Matthias Schwab, Georg F HoffmannAbstract:To evaluate the significance of inborn metabolic disorders of the pyrimidine degradation pathway, 450 children with unspecific neurological symptoms were comprehensively studied; 200 healthy children were recruited as controls. Uracil and thymine as well as their degradation products in urine were determined with an improved method based on reversed-phase HPLC coupled with electrospray ionization tandem mass spectrometry and detection by multiple-reaction monitoring using stable-isotope-labelled reference compounds as internal standards. From the results of the control group we established age-related reference ranges of all pyrimidine degradation products. In the patient group, two children with dihydropyrimidine dehydrogenase (DPYD) deficiency were identified; one of these was homozygous for the exon 14-skipping mutation of the DPYD gene. In addition, two patients with high uracil, dihydrouracil and beta-ureidopropionate were found to have ornithine transcarbamylase deficiency. In the urine of 9 patients, beta-alanine was markedly elevated owing to treatment with vigabatrin, an irreversible inhibitor of GABA transaminase, which interferes with beta-alanine breakdown. Four patients had exclusively high levels of beta-aminoisobutyrate (beta-AIB) due to a low activity of the D-beta-AIB-pyruvate aminotransferase, probably without clinical significance. In conclusion, quantitative investigation of pyrimidine metabolites in children with unexplained neurological symptoms, particularly epileptic seizures with or without psychomotor retardation, can be recommended as a helpful tool for diagnosis in clinical practice. Sensitive methods and age-related reference ranges enable the detection of partial enzyme deficiencies.
Dirk Kohlmuller - One of the best experts on this subject based on the ideXlab platform.
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comprehensive analysis of pyrimidine metabolism in 450 children with unspecific neurological symptoms using high pressure liquid chromatography electrospray ionization tandem mass spectrometry
Journal of Inherited Metabolic Disease, 2005Co-Authors: Christiane Schmidt, Ute Hofmann, Dirk Kohlmuller, Thomas E Murdter, Ulrich M Zanger, Matthias Schwab, Georg F HoffmannAbstract:To evaluate the significance of inborn metabolic disorders of the pyrimidine degradation pathway, 450 children with unspecific neurological symptoms were comprehensively studied; 200 healthy children were recruited as controls. Uracil and thymine as well as their degradation products in urine were determined with an improved method based on reversed-phase HPLC coupled with electrospray ionization tandem mass spectrometry and detection by multiple-reaction monitoring using stable-isotope-labelled reference compounds as internal standards. From the results of the control group we established age-related reference ranges of all pyrimidine degradation products. In the patient group, two children with dihydropyrimidine dehydrogenase (DPYD) deficiency were identified; one of these was homozygous for the exon 14-skipping mutation of the DPYD gene. In addition, two patients with high uracil, dihydrouracil and beta-ureidopropionate were found to have ornithine transcarbamylase deficiency. In the urine of 9 patients, beta-alanine was markedly elevated owing to treatment with vigabatrin, an irreversible inhibitor of GABA transaminase, which interferes with beta-alanine breakdown. Four patients had exclusively high levels of beta-aminoisobutyrate (beta-AIB) due to a low activity of the D-beta-AIB-pyruvate aminotransferase, probably without clinical significance. In conclusion, quantitative investigation of pyrimidine metabolites in children with unexplained neurological symptoms, particularly epileptic seizures with or without psychomotor retardation, can be recommended as a helpful tool for diagnosis in clinical practice. Sensitive methods and age-related reference ranges enable the detection of partial enzyme deficiencies.