In this international, retrospective cohort study, we collected data on age at symptom onset, age at death, and disease duration for patients with pathogenic mutations in the GRN and MAPT genes and pathological expansions in the C9orf72 gene through the Frontotemporal Dementia Prevention Initiative and from published papers.
Tauopathies such as Alzheimer's disease (AD), Pick's disease (PiD), Frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) etc. represent a group of age-related neurodegenerative disorders in which tau protein loses its normal conformation mostly due to hyperphosphorylation and subsequent formation of the aggregates of defined shapes, known as Neurofibrillary Tangles (NFTs).
Neuropathological analysis in Alzheimer's disease (AD) and experimental evidence in transgenic models overexpressing frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17) mutant tau suggest that amyloid-β pathology enhances the development of tau pathology.
The missense mutation in the Mapt gene in the P301S mouse model of FTD results in impaired synaptic function and microgliosis at three months of age, which are the earliest manifestations of disease.
We report the novel p.P397SMAPT variant in eight subjects from five apparently nonrelated families suffering from frontotemporal dementia with autosomal dominant pattern of inheritance.
Of the cohort of 73 participants, eight mutation carriers (three GRN, five MAPT) developed clinical features of frontotemporal dementia ('converters').
In human neurons, deviations from the ∼1:1 physiological 4R:3R ratio lead to frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17).
We further qualitatively assessed the cellular patterns of frontoinsular tau aggregation in FTLD-tau/MAPT using antibodies specific for tau hyperphosphorylation, acetylation, or conformational change.
The assembly of tau protein into abnormal filaments and brain cell degeneration are characteristic of a number of human neurodegenerative diseases, including Alzheimer's disease and frontotemporal dementia and parkinsonism linked to chromosome 17.
More than 50 different intronic and exonic autosomal dominant mutations in the tau gene have been linked to the neurodegenerative disorder frontotemporal dementia with Parkinsonism linked to chromosome-17 (FTDP-17).
The microtubule-associated protein tau undergoes aberrant modification resulting in insoluble brain deposits in various neurodegenerative diseases, including frontotemporal dementia (FTD), progressive supranuclear palsy, and corticobasal degeneration.
Through genetic screening of 165 cases possibly associated with tauopathies, including 88 Alzheimer's disease, 26 behavioral variant FTD, eight primary progressive aphasia, nine FTD with motor neuron disease, 21 progressive supranuclear palsy, and 13 corticobasal syndrome, we identified two novel MAPT variants: a heterozygous missense variant, p.P160S, in a patient with FTD with motor neuron disease and a heterozygous insertional variant, p.K298_H299insQ, in three patients with familial progressive supranuclear palsy.
Anatomical MRI, diffusion tensor imaging (DTI) and resting-state functional MRI data were collected in 55 presymptomatic FTD mutation carriers (8 microtubule-associated protein Tau, 35 progranulin, and 12 chromosome 9 open reading frame 72) and 48 familial controls.
Mutations in the MAPT gene that encodes tau can cause frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), providing the clearest evidence that tauopathy plays a causal role in neurodegeneration.
Four patients with N279K mutant frontotemporal dementia and parkinsonism linked to chromosome 17/MAPT underwent [<sup>11</sup> C]PBB3-PET to estimate regional tau loads.
Diversity of 30-Mb haplotypes found in Barcelona and the inference of the mutation age in these populations, among other reasons, suggest that prevalence of FTD linked to P301LMAPT mutation is the result of a locally originated mutation.
Microtubule-associated protein Tau (MAPT) and GGGGCC (G<sub>4</sub>C<sub>2</sub>) repeat expansion in chromosome 9 open reading frame 72 (C9ORF72) are the major known genetic causes of frontotemporal dementia (FTD) and other neurodegenerative diseases, such as Amyotrophic Lateral Sclerosis (ALS).
A spectrum of missense mutations in the tau-encoding gene microtubule-associated protein tau (<i>MAPT</i>) can cause frontotemporal dementias. tau aggregation is postulated to spread by a prion-like mechanism.
Neurons in the post-mortem human FTD-MAPT cortex have a high incidence of nuclear invaginations, indicating that tau-mediated nuclear membrane dysfunction is an important pathogenic process in FTD.
We found genetic etiology in 6 patients: 2 mutations in the PSEN1 gene (p.Pro264Ser and p.Phe105Cys) in the EOAD patients, C9orf72 expansion and MAPT (c.1920+16C>T), mutation in the FTD group of patients as well as MAPT (c.1920+16C>T) mutation and likely pathogenic mutation in the TYROBP mutation (p.Asp32Asn) in patients with unspecified diagnosis.
Regardless, the original FTDP-17 nomenclature has been retained for patients with MAPT mutations, with such patients currently classified independently from the different sporadic forms of FTLD with tau-immunoreactive inclusions (FTLD-tau).