Changes in the voluntary muscles and the peripheral nerves in an autopsy case of MPS type II (Hunter).

Skeletal muscles and peripheral nerves obtained at autopsy from a fifteen-year-old boy who had mucopolysaccharidosis type II (Hunter) were examined. The muscles showed severe neurogenic atrophy, chiefly from a distal motor neuropathy due to damage of the intramuscular nerve terminals. There was only a very slight loss of motor neurons in the spinal cord, which itself could not explain the severe atrophy of the muscles. Contrary to former observations in Tay-Sachs disease, in which the telodendra of peripheral nerves had exhibited abundant intraaxonal storage phenomena, similar axonal distensions were not found in the present case.