MAPT p.V363I mutation in a patient with presenile dementia and late amyotrophic lateral sclerosis

There are limited reports of motor neuron disease associated with MAPT mutations. We present a woman, carrier of the pathogenic MAPT V363I mutation, who developed a presenile dementia and, after 7 years, amyotrophic lateral sclerosis affecting both bulbar and spinal segments. This mutation has been reported in ten previous cases with various cognitive phenotypes and corticobasal syndrome, but not motor neuron disease. We also review the handful of MAPT mutations associated with motor neuron disease.