Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is an autosomal dominant

neurodegenerative A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic ...

tauopathy Tauopathy belongs to a class of neurodegenerative diseases involving the aggregation of tau protein into neurofibrillary or gliofibrillary tangles in the human brain. Tangles are formed by hyperphosphorylation of the microtubule protein known ...

and

Parkinson plus syndrome Parkinson-plus syndromes (PPS) are a group of neurodegenerative diseases featuring the classical features of Parkinson's disease ( tremor, rigidity, akinesia/bradykinesia, and postural instability) with additional features that distinguish them f ...

. FTDP-17 is caused by mutations in the

MAPT The tau proteins (abbreviated from tubulin associated unit) are a group of six highly soluble protein isoforms produced by alternative splicing from the gene ''MAPT'' (microtubule-associated protein tau). They have roles primarily in maintainin ...

(microtubule associated protein tau) gene located on the q arm of

chromosome 17 Chromosome 17 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 17 spans more than 83 million base pairs (the building material of DNA) and represents between 2.5 and 3% of the total D ...

, and has three cardinal features: behavioral and personality changes, cognitive impairment, and motor symptoms. FTDP-17 was defined during the ''International Consensus Conference in Ann Arbor'', Michigan, in 1996.

Signs and symptoms

Pathophysiology

The pathogenetic mechanisms underlying the disorder are thought to be related to the altered proportion of tau isoforms or to the ability of tau to bind microtubules and to promote microtubule assembly.

Diagnosis

Definitive diagnosis of FTDP-17 requires a combination of characteristic clinical and pathological features and molecular genetic analysis. Genetic counseling should be offered to affected and at-risk individuals; for most subtypes, penetrance is incomplete.

Management

Currently, treatment for FTDP-17 is only symptomatic and supportive.

Prognosis

The prognosis and rate of the diseases progression vary considerably among individual patients and genetic kindreds, ranging from life expectancies of several months to several years, and, in exceptional cases, as long as two decades.

Epidemiology

The prevalence and incidence remain unknown but FTDP-17 is an extremely rare condition. It is caused by mutations in the

gene, which encodes a microtubule-binding protein. Over 100 families with 38 different mutations in the tau gene have been identified worldwide. The phenotype of FTDP-17 varies not only between families carrying different mutations but also between and within families carrying the same mutations.

References

External links

{{DEFAULTSORT:Frontotemporal Dementia And Parkinsonism Linked To Chromosome 17 Neurodegenerative disorders Brain disorders Cognitive disorders Genetic disorders with no OMIM