The neuropathology of frontotemporal lobar degeneration caused by mutations in the progranulin gene.
The most common pathology in frontotemporal dementia (FTD) is tau-negative, ubiquitin-immunoreactive (ub-ir) neuronal inclusions (FTLD-U). Recently, we identified mutations in the progranulin (PGRN) gene as the cause of autosomal dominant FTLD-U linked to chromosome 17. Here, we describe the neuropathology in 13 patients from 6 different families, each with FTD caused by a different PGRN mutation. The most consistent feature was the presence of ub-ir lentiform neuronal intranuclear inclusions (NII) in the neocortex and striatum. In addition, the neocortex showed moderate-to-severe superficial laminar spongiosis, chronic degenerative changes, ub-ir neurites and well-defined ub-ir neuronal cytoplasmic inclusions (NCI). In the striatum, there were numerous ub-ir neurites. NCI in the hippocampus usually had a granular appearance. In contrast, familial FTLD-U cases without PGRN mutations had no NII, less severe neocortical and striatal pathology and hippocampal NCI that were more often solid. Eight cases in which genetic analysis was not available also had NII and an overall pathology similar to those with proven mutations. None of our cases of FTLD-U without NII showed the same pattern of pathology as those with mutations. These findings suggest that FTD caused by PGRN mutations has a recognizable pathology with the most characteristic feature being ub-ir NII.
Mackenzie
Ian R A
IR
Department of Pathology and Laboratory Medicine, University of British Columbia and Vancouver Coastal Health Vancouver, BC, Canada. ian.mackenzie@vch.ca
Baker
Matt
M
Pickering-Brown
Stuart
S
Hsiung
Ging-Yuek R
GY
Lindholm
Caroline
C
Dwosh
Emily
E
Gass
Jennifer
J
Cannon
Ashley
A
Rademakers
Rosa
R
Hutton
Mike
M
Feldman
Howard H
HH
D000368:Aged; D003342:Corpus Striatum / Q000378:metabolism / Q000473:pathology; D003704:Dementia / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D002479:Inclusion Bodies / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D045586:Intranuclear Inclusion Bodies / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation; D019579:Neocortex / Q000378:metabolism / Q000473:pathology; D000077153:Progranulins; D012189:Retrospective Studies; D025801:Ubiquitin / Q000378:metabolism
C492314:GRN protein, human; D036341:Intercellular Signaling Peptides and Proteins; D000077153:Progranulins; D025801:Ubiquitin