Charcot-Marie-Tooth disease masquerading as acute demyelinating encephalomyelitis-like illness.

X-linked Charcot-Marie-Tooth disease (CMTX1) is a clinically heterogeneous hereditary motor and sensory neuropathy with X-linked transmission. Common clinical manifestations of CMTX1 disease, as in other forms of Charcot-Marie-Tooth (CMT) disease, are distal muscle wasting and weakness, hyporeflexia, distal sensory disturbance, and foot deformities. Mutations in the connexin-32 gene (gap junction protein β1 [GJB1]) are responsible for CMTX1 disease. In this report, we describe a patient with CMTX1 disease presenting with recurrent attacks of transient and episodic acute demyelinating encephalomyelitis (ADEM)-like symptoms without previous signs of lower extremity weakness or foot deformities; the patient, as well as his asymptomatic mother, exhibited a novel GJB1 mutation (p.Met1Ile). Differential diagnosis of recurrent and transient ADEM-like illness, if unexplained, should include the possibility of CMTX1 disease.