Frontotemporal dementia

As scientists have begun to decipher the molecular genetic bases of hereditary frontotemporal dementia (FTD), it has become clear that the biology of these human neurodegenerative diseases has a complexity not previously suspected. FTD has been found to be linked to several chromosomal loci including those in chromosome 9, chromosome 17, and chromosome 3.

The article by Guyant-Maréchal et al. in this issue of Neurology reports the clinical, pathologic, and molecular characteristics of a form of FTD associated with inclusion body myopathy and Paget disease of the bone observed in members of two families and expands our knowledge on genetically determined FTD.¹ The disorder is associated with mutations in the valosin-containing protein (VCP) gene located in chromosome 9q21.1-p12.^2,3 Guyant-Maréchal et al. elucidate and compare the phenotypic characteristics associated with the R93C and R155C mutations in exon 3 of the VCP gene. VCP plays a role in the ubiquitin-proteasome dependent degradation of cytosolic proteins and in the retrotranslocation of misfolded proteins from the endoplasmic reticulum into the cytoplasm. VCP mutations disrupt normal VCP functions leading to the accumulation of ubiquitinated proteins within cells and to the alteration of the ubiquitin-proteasome system. VCP is considered a chaperone protein with widespread expression in numerous cell types and …