title: Elevated serum biotinidase activity in hepatic glycogen storage disorders--a convenient biomarker.
abstract: An elevated serum biotinidase activity in patients with glycogen storage disease (GSD) type Ia has been reported previously. The aim of this work was to investigate the specificity of the phenomenon and thus we expanded the study to other types of hepatic GSDs. Serum biotinidase activity was measured in a total of 68 GSD patients and was compared with that of healthy controls (8.7 +/- 1.0; range 7.0-10.6 mU/ml; n = 26). We found an increased biotinidase activity in patients with GSD Ia (17.7 +/- 3.9; range: 11.4-24.8; n = 21), GSD I non-a (20.9 +/- 5.6; range 14.6-26.0; n = 4), GSD III (12.5 +/- 3.6; range 7.8-19.1; n = 13), GSD VI (15.4 +/- 2.0; range 14.1-17.7; n = 3) and GSD IX (14.0 +/- 3.8; range: 7.5-21.6; n = 22). The sensitivity of this test was 100% for patients with GSD Ia, GSD I non-a and GSD VI, 62% for GSD III, and 77% for GSD IX, indicating reduced sensitivity for GSD III and GSD IX, respectively. In addition, we found elevated biotinidase activity in all sera from 5 patients with Fanconi-Bickel Syndrome (15.3 +/- 3.7; range 11.0-19.4). Taken together, we propose serum biotinidase as a diagnostic biomarker for hepatic glycogen storage disorders.
authors.affiliation: Division of Metabolism and Molecular Pediatrics, University Children's Hospital, Steinwiesstrasse 75, CH-8032, Zurich, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Paesold-Burda
authors.forename: M R
authors.initials: MR
authors.lastname: Baumgartner
authors.forename: R
authors.initials: R
authors.lastname: Santer
authors.forename: N U
authors.initials: NU
authors.lastname: Bosshard
authors.forename: B
authors.initials: B
authors.lastname: Steinmann
mesh_terms: D015415:Biomarkers / Q000378:metabolism*; D043523:Biotinidase / Q000097:blood*; D004252:DNA Mutational Analysis; D006003:Glycogen / Q000378:metabolism; D005953:Glycogen Storage Disease Type I / Q000097:blood / Q000235:genetics*; D006009:Glycogen Storage Disease Type II / Q000097:blood / Q000235:genetics; D006010:Glycogen Storage Disease Type III / Q000097:blood / Q000235:genetics; D006013:Glycogen Storage Disease Type VI / Q000097:blood / Q000235:genetics; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008107:Liver Diseases / Q000201:enzymology; D012680:Sensitivity and Specificity; D013048:Specimen Handling
chemical_list: D015415:Biomarkers; D006003:Glycogen; D043523:Biotinidase