Giant axonal neuropathy (GAN) is a rare pediatric neurodegenerative disease. It 
is best known for the "giant" axons caused by accumulations of intermediate 
filaments. The disease is progressive, with onset around age 3 years and death 
by the third decade of life. GAN results from recessive mutations in the GAN 
gene encoding gigaxonin, and our analysis of all reported mutations shows that 
they are distributed throughout the protein structure. Precisely how these 
mutations cause the disease remains to be determined. In addition to changes in 
peripheral nerves that are similar to those seen in neuropathies such as 
Charcot-Marie-Tooth type 2, GAN patients exhibit a wide range of central nervous 
system signs. These features, corroborated by degeneration of central tracts 
apparent from postmortem pathology, indicate that GAN is also a progressive 
neurodegenerative disease. To reflect this phenotype more precisely, we 
therefore propose that the disease should be more appropriately referred to as 
"giant axonal neurodegeneration."