Peripheral nerve involvement in Hunter syndrome (mucopolysaccharidosis II)

A 20-year-old man with confirmed Hunter syndrome had entrapments of median and ulnar nerves. Sural nerve biopsy specimen revealed clear, lamellated, and granular inclusions in Schwann cells, fibroblasts, and perineurial cells. The clear inclusions are believed to represent storage of mucopolysaccharide, and the zebra bodies, ganglioside. Focal alterations in myelin were found, associated with moderately dense granular inclusions. Following carpal tunnel release operations, the patient experienced dramatic releif of symptoms.