Inherited metabolic disease resulting in accumulation
of abnormal glycogen in different tissues of the body.
Cori Disease; Forbes Disease; Illingworth-Cori-Forbes
Disease; Amylo-1,6-Glucosidase Debrancher Deficiency; Glycogenosis III;
Debranching Enzyme Deficiency; Limit Dextrinosis.
Incidence of GSD type III in the United States and other
countries is estimated to make up for 24% of all patients affected with GSD.
Autosomal recessive. The responsible defect has been mapped to 1p21.
Deficiency of amylo-1,6-debrancher enzyme, an
enzyme found in all tissues, that converts glycogen to
glucose-1,6-phosphate, resulting in accumulation of dextrin. The site of
glycogen accumulation is primarily cytoplasmic. Disease results from
generalized liver and muscle (GSD IIIa) or isolated (liver only) deficiency
of glycogen debranching enzyme (GSD IIIb).
Low blood glucose levels, elevated glycogen content in
red blood cells, and elevated levels of fat. Uric acid and lactic acid
levels are usually normal. Liver biopsy shows inflammatory changes,
significantly abnormally structured glycogen content, and deficiency of the
debrancher enzyme. Biopsy of muscle shows an accumulation of abnormally
structured glycogen in type IIIa.
Affected organs vary. Moderate-to-marked
hepatomegaly. May have moderate hypotonia and cardiomegaly. Hypoglycemia is
rare (but can be profound), occurring mainly after fasting periods. Hepatic or cardiac failure is
rare. Normal mental development. May have recurrent pneumonia. Muscle
weakness is commonly present in childhood and occasionally is severe. Often
the liver returns to a normal size at puberty, although the enzyme defect
persists and transition into hepatic cirrhosis and later hepatocellular carcinoma is a known complication.
Survival to adulthood however is common.
Assess extent of cardiac or hepatic
involvement. Assess extent of muscle weakness, which can become a prominant feature after
puberty in GSD IIIa. Treat intercurrent
No specific difficulties with anesthesia
have been described. A bleeding tendency may be present, which
contraindicates regional anesthesia (central block procedures). Although
hypoglycemia is rarely a clinical problem, blood glucose concentrations
should be measured in the perioperative period and intravenous dextrose-containing solutions
given if required. Depending on the operation, prolonged mechanical ventilation
may be required postoperatively in patients with predominant muscle weakness.
Muscle relaxants and drugs with
prolonged sedative properties should be used cautiously in children with
marked hypotonia. If cardiac function is reduced, agents should be selected
to avoid further myocardial depression.
Other glycogen storage
Cox JM: Anesthesia and glycogen-storage disease. Anesthesiology
Kiechl S, Kohlendorfer U, Thaler C, et al: Different clinical aspects of
debrancher deficiency myopathy. J Neurol Neurosurg Psychiatry