Glycogen Storage Disease Type VIII (GSD VIII)

At a glance

One of the mildest form of the glycogenoses. It is characterized by hepatomegaly, growth retardation, elevation of glutamate-pyruvate transaminase and glutamate-oxaloacetate transaminase, hypercholesterolemia, hypertriglyceridemia, and fasting hyperketosis.

Synonyms

Hepatic Phosphorylase Kinase Deficiency; Liver Phosphorylase Kinase Deficiency; Phosphorylase Kinase Deficiency of Liver; Phosphorylase Kinase-Deficient Liver Glycogenosis; Glycogenosis Type VIII.

Incidence

Fewer than 10 cases have been reported, but it may be underdiagnosed because it is often asymptomatic and, when symptomatic, usually classified as a GSD VI.

Genetic inheritance

X-linked recessive (GSD VIII) and autosomal recessive (GSD IX) types described. Gene map loci are Xp22.2-p22.1 (GSD VIII) and 16q12-q13 (GSD IX).

Pathophysiology

Deficiency of liver phosphorylase kinase, which is required to activate liver phosphorylase. Protein phosphorylation is a major mechanism of signal transduction.

Diagnosis

Clinical finding of hepatomegaly. Enzyme deficiency on liver biopsy.

Clinical aspects

Massive hepatomegaly in infancy that may regress later in life. Otherwise, children are normal and prognosis is good.

Precautions before anesthesia

Check liver function.

Anesthetic considerations

Anesthetic management has not been described. If hepatomegaly is significant, functional residual capacity of the lungs may be reduced. Proper preoxygenation would be recommended. Case reports exist where hepatomegaly finally progressed to liver cirrhosis and formation of a hepatocellular adenoma.

Pharmacological implications

No agents specifically contraindicated.

Other condition to be considered

Other glycogen storage diseases described in this section.

References