A case of dementia parkinsonism resembling progressive supranuclear palsy due to mutation in the tau protein gene

Background: Few cases of frontotemporal dementia parkinsonism (FTDP-17) have been described in the literature. To our knowledge, this is the first Italian case. Objective: To report a case of FTDP linked to chromosome 17, exhibiting progressive supranuclear palsy on initial examination. Patient: A 50-year-old woman had a 4-year history of behavior changes associated with slowly progressive mental decay and parkinsonism, with poor balance, supranuclear vertical gaze palsy, and bradykinesia. The symptoms were not responsive to dopaminergic therapy. Her father had died at age 46 years after a 7-year history of parkinsonism, and her brother, diagnosed as having progressive supranuclear palsy, died at age 45 years. Results: Magnetic resonance imaging showed mild midbrain atrophy, results of an electroencephalogram were normal, and cognitive evaluation showed moderate cognitive impairment, especially evident in the executive and attentional functions. Genetic testing revealed a tau gene mutation at codon 279 (AAT-->AAG) of exon 10. Conclusion: Exon 10 mutations (including the N279K mutation) that result in overproduction of the tau isoform with 4 microtubule binding motifs seem to be associated with a mainly parkinsonian phenotype at disease onset.