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Case Reports in Genetics
Volume 2011, Article ID 768610, 3 pages
Case Report

A De Novo Whole GCK Gene Deletion Not Detected by Gene Sequencing, in a Boy with Phenotypic GCK Insufficiency

1Department of Pediatric, Aarhus University Hospital, Skejby, 8200 Aarhus C, Denmark
2Department of Clinical Genetic, Aarhus University Hospital, Nørrebrogade, 8200 Aarhus C, Denmark
3Hagedorn Research Institute, 2820 Gentofte, Denmark
4Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, 1350 Copenhagen K, Denmark
5University of Aarhus, 8200 Aarhus C, Denmark
6Steno Diabetes Center, 2820 Gentofte, Denmark
7Faculty of Health Sciences, University of Southern Denmark, 5000 Odense C, Denmark

Received 13 July 2011; Accepted 18 August 2011

Academic Editors: A. Baumer, C.-W. Cheng, and C. Yapijakis

Copyright © 2011 N. H. Birkebæk et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We report on a boy with diabetes mellitus and a phenotype indicating glucokinase (GCK) insufficiency, but a normal GCK gene examination applying direct gene sequencing. The boy was referred for diabetes mellitus at 7.5 years old. His father, grandfather and great grandfather suffered type 2 DM. Several blood glucose profiles showed (BG) of 6.5–10 mmol/L L. After three years on neutral insulin Hagedorn (NPH) in a dose of 0.3 IU/kg/day haemoglobin A1c (HbA1c) was 6.8%. Treatment was changed to sulphonylurea 750 mg a day, and after 4 years HbA1c was 7%. At that time a multiplex ligation-dependent amplification gene dosage assay (MLPA) was done, revealing a whole GCK gene deletion. Medical treatment was ceased, and after one year HbA1c was 6.8%. This case underscores the importance of a MLPA examination if the phenotype of a patient is strongly indicative of GCK insufficiency and no mutation is identified using direct sequencing.