Type III Glycogen Storage Disease (Forbes-Cori Disease) Clinical Presentation

Updated: Jul 21, 2021
  • Author: Ricardo R Correa Marquez, MD, EsD, FACP, FACE, FAPCR, CMQ, ABDA, FACHT; Chief Editor: George T Griffing, MD  more...
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Early clinical findings include hepatomegaly (98%), hypoglycemia (53%), failure to thrive (49%), and recurrent illness and/or infections (17%). [13]

Laboratory findings include ketonic hypoglycemia, hyperlipidemia, and elevated hepatic transaminases. [2]

Myopathy presents as muscle weakness and elevated creatine kinase (CK); it progresses slowly and becomes prominent in the third to fourth decade of life.

Cognitive deficits—impaired working memory, planning skills, the capacity to elaborate and maintain strategies, conceptualization and rule generation, and a generalized slowness—have been described in patients with GSD III. [14]


Physical Examination

Hepatomegaly is the most common presenting sign in patients with GSD III. Hepatomegaly usually resolves during puberty, and growth accelerates, with the attainment of normal adult height. [15]  In adult patients with GSD III, a decrease in liver progression may be a sign of liver cirrhosis; the median age of cirrhosis diagnosis is 18 years old. [13]

Cardiac findings vary according to the degree and type of cardiac involvement. The most common cardiac abnormality in patients with GSD III is left ventricular hypertrophy [1] ; findings on physical examination include a sustained, displaced point of maximal impulse.