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Updated: Aug 29, 2026

Radiochemical Assessment of Glycogen Synthase Enzyme Activity in Animal Tissue
Published on: October 24, 2025
Markedly elevated serum biotinidase activity may indicate glycogen storage disease type Ia
B Wolf1, C L Freehauf, J A Thomas
1Department of Pediatrics, Connecticut Children's Medical Center, 282 Washington Street, Hartford, CT 06106, USA. bwolf@ccmckids.org
Abstract:
We report two children who presented with symptoms suggestive of biotinidase deficiency. Rather than deficiency, markedly elevated serum biotinidase activities were found. Based upon literature reports of elevated biotinidase activities in children with glycogen storage disease (GSD) type Ia, we considered the latter in our differential diagnosis and subsequently confirmed GSD type Ia in both patients by enzymatic testing. GSD type Ia should be considered in children with markedly elevated serum biotinidase activity.
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