After a century of study, mutations in connexin32, peripheral myelin protein22, and protein zero are now known to culminate in the prototypical phenotype of Charcot-Marie-Tooth disease. Many of these mutations have been modeled in rodents and in tissue culture. Consequently, structure—function predictions for these mutations are now possible and detailed analyses of many of them are ongoing. Despite the marked differences in the functions of these three proteins, it is profitable to consider the many similarities between them, including the types of mutational mechanisms and their effects on myelin structure and function. Accordingly, the biology and genetics of Charcot-Marie-Tooth disease and other inherited peripheral neuropathies due to mutations in these proteins are reviewed.