Transient leukoencephalopathy associated with X-linked Charcot-Marie-Tooth disease.

X-linked hereditary demyelinating neuropathy (Charcot-Marie-Tooth 1X) accounts for 10% to 20% of all hereditary demyelinating neuropathies and is caused by mutations in the GJB1 gene, which codes for connexin 32. Connexin 32 is a gap junction protein widely expressed in Schwann cells as well as oligodendrocytes. Transient leukoencephalopathy has been reported in children and adults with Charcot-Marie-Tooth 1X. The case of a previously healthy 10-year-old boy who presented with fluctuating neurological deficits is reviewed. His brain magnetic resonance imaging scans showed abnormal restricted diffusion and mild hyperintense T2-weighted and fluid attenuation inversion recovery abnormalities in the splenium of the corpus callosum and the posterior cerebral white matter in a bilaterally symmetric distribution. A family history of Charcot-Marie-Tooth disease was revealed late in his presentation, and genetic testing identified a mutation in the GJB1 gene that has not previously been associated with central nervous system involvement.