Abstract: Specific mutations in the connexin-32 gene that are associated with X-linked Charcot-Marie-Tooth (CMT) disease are disclosed. Methods of diagnosing X-linked CMT disease are also disclosed. Methods include hybridization analysis, such as Southern or Northern analysis, which use hybridization of mutant connexin-32 nucleic acid probes to connexin-32 genes; direct mutation analysis by restriction digest; sequencing of the connexin-32 gene; hybridization of an allele-specific oligonucleotide with genomic DNA; or identification of mutant connexin-32 proteins. Mutant connexin-32 nucleic acid probes are also disclosed. The mutant connexin-32 nucleic acid probes have a mutation in at least one of the following codons: 13, 16, 20, 28, 29, 41, 75, 79, 80, 85, 86, 94, 106, 124, 131, 158, 161, 169, 178, 180, 189, 191, 193, 219, 220, 230, and 267.