Quantitative histologic study of the sural nerve in Lesch-Nyhan syndrome.

The sural nerve of a 31-year-old man with Lesch-Nyhan syndrome obtained at autopsy was studied histologically. Large, myelinated nerve fibers were reduced in number and no myelinated nerve fibers larger than 5 microns were seen. Diameter distribution of myelinated nerve fibers did not demonstrate a bimodal pattern. The density of myelinated nerve fibers was 5,530/mm2 and was decreased as compared to the controls. On electron microscopic examination, lipid-like inclusions were observed in the cytoplasm of some Schwann cells. The role of these inclusions could not be elucidated, but reduction of larger myelinated nerve fibers suggests a peripheral nervous disorder in patients with this syndrome; therefore, patients with Lesch-Nyhan syndrome must be reappraised for disorders of the peripheral nervous system.