A 7-year-old female presented with fever, urinary incontinence, mental regression, gait disturbance, and lethargy after diarrhea. Magnetic resonance imaging revealed multifocal T(2)-weighted hypersignal lesions supportive of acute disseminated encephalomyelitis. Her mother had been diagnosed with hereditary neuropathy with susceptibility to pressure palsy. The girl was also determined to have hereditary neuropathy with liability to pressure palsy, with a 1.5-Mb deletion in chromosome 17p11.2 encompassing the gene for peripheral myelin protein 22 detected by fluorescent in situ hybridization. Hereditary peripheral neuropathies may be a factor in triggering the autoimmune demyelinating disorder of the central nervous system.