CMT type 1 (CMT1; MIM 118200) is a group of autosomal dominant-inherited demyelinating neuropathies with a disease onset at or after childhood. Five different subtypes have been identified based on different causative genes. Among them, CMT1A (MIM #118220) is most common and is usually associated with a duplication of a 1.5-Mb region on chromosome 17p11.2, which includes peripheral myelin protein 22 gene (PMP22; MIM *601097)