CMT1B Patient with a Novel p.Arg98Leu MPZ Variant Mimicking Chronic Inflammatory Demyelinating Polyneuropathy on Electrodiagnostic Testing

Conduction block or temporal dispersion on motor nerve conduction studies (NCSs) are known as key features of chronic inflammatory demyelinating polyneuropathy. Some types of CharcotMarieTooth disease (CMT) have been also reported to show conduction block or temporal dispersion on NCS. We experienced a case who presented with slowly progressive motor weakness, sensory loss, foot deformity, and segmental demyelination on NCS. We confirmed her and her mother harboring CMT1B with a novel p.Arg98Leu MPZ variant.