The most common type of Charcot-Marie-Tooth disease is caused by a duplication of PMP22 leading to dysmyelination, axonal loss and progressive muscle weakness (CMT1A).
Charcot-Marie-Tooth disease type 1A is an autosomal dominant polyneuropathy due to peripheral myelin protein 22 gene duplication and characterized by slowly progressive distal limb muscle weakness, atrophy and sensory loss with foot deformities.
Heterozygous PMP22-transgenic rats develop muscle weakness and gait abnormalities as well as reduced nerve conduction velocities and EMG abnormalities, which closely resemble recordings in patients with CMT1A.