The underlying genetic cause of CMTX3 is a genomic rearrangement between chromosome 8q24.3 and chromosome Xq27.1. Because this involves the X chromosome, this is an X-Linked CMT.

CMTX3 symptom onset usually occurs within the first 5 years, but can be as late as 10 years old. CMTers who have CMTX3 usually experience severe foot deformities and lower limb weakness with sensory loss early in life, followed by the same in the upper limbs within 10 years of symptom onset. CMTX3 demonstrates both demyelinating and axonal neuropathy properties. CMTX3 tends to have an earlier onset than CMTX1, and typically causes more severe hand weakness and an overall faster progression than CMTX1.

A trait that sets all X-Linked CMT apart from the other types of CMT is that there can be no male-to-male transmission. Also, males who have X-Linked CMT tend to be more severely affected than females who have X-Linked CMT.