Genetics and neurobiology of frontotemporal lobar degeneration.

Frontotemporal dementia (FTD) is characterised by brain intracellular deposition of abnormally phosphorylated tau protein, considered responsible for neuronal death. Several familial cases with different mutations in the tau encoding gene (MAPT), located on chromosome 17, have been described. Besides, in a Danish family, the genetic defect has been associated to chromosome 3. Although many FTD families exhibit known mutations, in some cases none of them occur. Recent findings demonstrate an increased intrathecal production of both pro- and anti-inflammatory cytokines in sporadic FTD patients. Besides, increased cerebrospinal fluid monocyte chemotactic protein-1 and interleukin-8 levels have been observed in FTD, whereas interferon-gamma-inducible protein-10 levels were similar to controls.