Childhood giant axonal neuropathy. Case report and review of the literature.

Giant axonal neuropathy (GAN) is a rare autosomal recessive childhood disorder characterized by a peripheral neuropathy and features of central nervous system involvement. Typically seen are distal axonal swellings filled with 8-10 nm in diameter neurofilaments in central and peripheral axons, and intermediate filament collections in several other cell types. Many neurotoxins produce a morphologically similar neuropathy in humans and experimental animals. Defective nerve fiber energy metabolism has been postulated as a cause in these toxic neuropathies. It is possible that GAN represents an inborn error of metabolism of enzyme-linked sulfhydryl containing proteins, resulting in impaired production of energy necessary for the normal organization of intermediate filaments.