Congenital giant axonal neuropathy

Giant axonal neuropathy (GAN) is a distal sensorimotor neuropathy, characterized by neurofilamentous axonal swellings, with usual onset at 2 to 3 years of age. We report a case of congenital GAN with hypotonia at birth. At 7 months of age, nerve conduction studies showed almost complete lack of sensory and motor responses in the lower extremities. A sural nerve biopsy specimen disclosed absence of myelinated axons. Autopsy, following death at 15 months of age, revealed axonal swellings in peripheral nerves and distal degeneration of long spinal cord tracts. The neurofilamentous content of the axonal swellings was confirmed by Glees-Marsland staining and immunoperoxidase reaction with antibodies to neurofilaments. Axonal swellings did not stain with periodic acid-Schiff and were not seen in the cerebral cortex or brain stem, distinguishing this process from infantile neuroaxonal dystrophy. This patient illustrates congenital GAN with subsequent rapid progression.