Thirteen families have been described with an autosomal dominantly inherited dementia named frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), historically termed Pick's disease.
In addition, the recent identification of mutations in the tau gene associated with a similar neurodegenerative condition (frontotemporal dementia and parkinsonism linked to chromosome 17) has further strengthened the argument that tau dysfunction is somehow involved in the pathogenesis of PSP.
We also examined postural sway in mice expressing mutations that mimic frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17) (T-279, P301L or P301L-nitric oxide synthase 2 (NOS2)(-/-) mice) and that demonstrate motor symptoms.
The relevance of tau dysfunction for neurodegeneration has been clarified through the identification of mutations in the Tau gene in cases with frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17).
They include the largely sporadic Alzheimer's disease (AD), progressive supranuclear palsy, corticobasal degeneration, Pick's disease and argyrophilic grain disease, as well as the inherited frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17).
In addition to FTDP-17, altered tau isoform levels are also pathogenically associated with other FTD disorders such as progressive supranuclear palsy (PSP), corticobasal degeneration and Pick's disease; however, the mechanisms remain undefined and mutations in tau have not been detected.
Here, we describe a new mutation of the tau gene, a T --> C transition at position +11 of the intron following exon 10 (T --> C 3'E10 +11) in the family showing frontotemporal dementia with very early age of onset (the first decade of proband's life).
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.
Compared with cells overexpressing wild-type Tau, cells overexpressing FTD-associated MAPT mutations produce significantly less extracellular total Tau without altering intracellular total Tau levels.
To better understand the role of tau-mediated effects on pathophysiology and global central nervous system function, we extensively characterized gene expression, pathology and behavior of the rTg4510 mouse model, which overexpresses a mutant form of human tau that causes Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17).
Tau is not only a basic component of neurofibrillary degeneration, but is also an aetiological factor, as demonstrated by mutations on the tau gene responsible for frontotemporal dementias with parkinsonism linked to chromosome 17.
These data argue that additional genes may confer disease risk to PSP and CBS, and to FTD as well, beyond the MAPT tau haplotype.Further studies are warranted.
Furthermore, we analyzed some markers located in the common region of linkage (D17S800-D17S791), associated with some cases of familial frontotemporal dementia (FTDP-17), and the SNPs rs1816 and rs937 close to the tau gene, to determine their possible association with sporadic PSP.
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).
We screened a cohort of 48 patients with familial frontotemporal dementia (FTD) negative forMAPT, GRN, and C9orf72 mutations for other known FTD genes by using whole exome sequencing.
The discovery of mutations in the tau gene, located on Chromosome 17 and its relationship to frontotemporal dementia with Parkinsonism (FTDP-17) has enhanced the importance of tau protein in cognitive neurology.
Mutations in the Progranulin gene (PGRN) recently have been discovered to be associated with frontotemporal dementia (FTD) linked to 17q21 without identified MAPT mutations.
Missense mutations of the tau gene cause autosomal dominant frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), an illness characterized by progressive personality changes, dementia, and parkinsonism.