Adult polyglucosan body disease is a late-onset, slowly progressive, autosomal recessive disorder affecting the central and peripheral nervous systems. Patients typically present after age 40 years with a variable combination of cognitive impairment, pyramidal tetraparesis, peripheral neuropathy, and neurogenic bladder. Other manifestations include cerebellar dysfunction and extrapyramidal signs. THis disease is an allelic disorder to type IV glycogen storage disease with GBE1 mutations (MIM.232500).

Synopsis

 widespread accumulation of round, intracellular polyglucosan bodies throughout the nervous system, which are confined to neuronal and astrocytic processes.
 neurogenic bladder
 micturition difficulties
 gait disturbance
 upper motor neuron signs
 pyramidal tetraparesis
 cognitive impairment
 white matter abnormalities (MRI)
 polyglucosan bodies (round intracellular inclusions) found in neuronal and astrocytic processes
 peripheral neuropathy
 distal sensory impairment
 paresthesias
 Onset after age 40 years
 Slowly progressive disease

Etiology

 adult polyglucosan body disease is caused by germline mutation in the glycogen branching enzyme gene GBE1 (MIM.607839).

• Mutation in the same gene GBE1 causes type IV glycogen storage disease (GSD IV) (MIM.232500), an early childhood disorder with systemic manifestations.
• Decreased or absent glycogen branching enzyme activity