Two brothers with frontotemporal dementia and parkinsonism with an N279K mutation of the tau gene

To the Editor: The article by Arima et al.1 shows another Japanese family with frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) with N279K mutation on the microtubule-associated protein tau gene. There are three other families with this mutation: a family with pallido-ponto-nigral degeneration (PPND), a French family with dementia with supranuclear palsy, and a Japanese family with pallido-nigro-luysian degeneration.2 All four families have pronounced parkinsonian signs in addition to dementia, personality and behavior changes, pyramidal dysfunction, supranuclear palsy, apraxia, dystonia, dysphasia, cachexia, and other features. Arima et al.1 raise an important point regarding the response of the affected individuals with N279K mutation to antiparkinsonian therapy. One of their patients had responded beneficially to anticholinergic medications, amantadine, and levodopa. The positive response lasted 2 years. The patient was in the initial stage of …