glycogen storage disease type-III (Cori-Forbes type glycogen storage disease)

Classification

3-4 types recognized:

• GSD type 3A patients lack glycogen debrancher enzyme activity in both liver & muscle
• GSD type 3B patients are enzyme-deficient in liver only
• GSD type 3C (rare) selective loss of only 1 of the 2 debranching activities, the glucosidase activity
• GSD type 3D (rare) selective loss of only 1 of the 2 debranching activities, the transferase activity

Pathology

• accumulation of abnormal glycogen with short outer chains

Genetics

• associated with defect in AGL gene

Clinical manifestations

• variable degrees of hepatomegaly, muscle weakness, fasting hypoglycemia, short stature

Laboratory

• normal response of plasma glucose to IM glucagon after food; poor after fasting
• AGL gene mutation
• amylo-alpha-1,6-glucosidase in leukocytes

More general terms

• glycogen storage disease (glycogenosis)

Additional terms

• glycogen debranching enzyme; glycogen debrancher [includes: 4-alpha-glucanotransferase, oligo-1,4-1,4-glucantransferase; amylo-alpha-1,6-glucosidase, amylo-1,6-glucosidase, dextrin 6-alpha-D-glucosidase] (AGL, GDE)

Database

• OMIM: https://mirror.omim.org/entry/232400