Isolated vitamin E deficiency mimicking distal hereditary motor neuropathy in a 13-year-old boy.

We report an atypical neurophysiologic pattern of isolated vitamin E deficiency in a 13-year-old boy. Electroneurography- electromyography, somatosensory evoked potentials, serum vitamin E concentration and genetic analysis of the alpha-tocopherol transfer protein gene were performed. Nerve conduction study failed to show peripheral neuropathy whereas needle electromyography of distal muscles demonstrated chronic neurogenic motor unit potentials. Both clinical and neurophysiologic data fulfilled the criteria of distal hereditary motor neuropathy. Later on, somatosensory-evoked potential displayed absence of spinal and central response. The serum vitamin E level was low, and the patient was found to be homozygous for a 513insTT mutation in exon 3 of the alpha-tocopherol transfer protein gene. To our knowledge this is the first case of isolated deficiency of vitamin E that presents the classic neurophysiologic and clinical features of distal hereditary motor neuropathy.