type III glycogen storage disease

Last reviewed 08/2021

Forbes' disease is a glycogen storage disease that affects liver and muscle. It is characterized by the deposition of an abnormal glycogen structure and is caused by an amylo-1,6-glucosidase defect, the usual function of which is as a debranching enzyme.

Diagnosis is based on biochemical assay of leucocytes, liver or muscle.

Life expectancy is not affected significantly by this condition. Management is to avoid fasting - for example overnight infusions of calories and feed with uncooked corn starch, which releases calories slowly.