Liver Biopsy-Associated Diagnosis of Glycogen Storage Disease Type IV (Andersen Disease).

Glycogen storage disease type IV (Andersen disease) is caused by a deficiency of the glycogen branching enzyme. We report a case in which liver biopsy played a key role in establishing the diagnosis. A 2-year-old girl presented to our hospital with hepatomegaly. Despite extensive testing, no definitive diagnosis was made, prompting a liver biopsy. The biopsy tissue revealed characteristic cytoplasmic inclusions. Genetic analysis identified a mutation in the GBE1 gene, confirming the diagnosis of glycogen storage disease type IV. Various special stains were helpful in characterizing the accumulated substances.