Clinicopathologic features of frontotemporal dementia with progranulin sequence variation.
BACKGROUND
Frontotemporal lobar degeneration with ubiquitin-immunoreactive (ub-ir) inclusions (FTLD-U) has been associated with frontotemporal dementia (FTD) and ALS. Recently, mutations in Progranulin (PGRN), predicted to cause premature truncation of the PGRN coding sequence, were found in patients with inherited FTLD-U and ub-ir neuronal intranuclear inclusions (NII).


OBJECTIVE
To describe clinical, pathologic, and genetic features of three FTD patients having either a family history of FTD (A.III.1 and B.II.1) or of ALS (C.III.1).


METHODS
Patients underwent a single clinical assessment, MRI, and [(18)F]fluorodeoxyglucose PET brain scan. Neuropathologic examination and genetic analyses were carried out.


RESULTS
Patients presented clinically with the behavioral variant of FTD. Language dysfunctions were marked with comprehension being particularly affected. Neuroimaging revealed frontotemporal atrophy and glucose hypometabolism, with predominant left-side involvement, in Patients A.III.1 and B.II.1. Subject C.III.1 displayed mild atrophy and symmetric anterior hypometabolism. All patients were neuropathologically diagnosed with FTLD-U. Ub-ir NII were noted in Patients A.III.1 and B.II.1 but were absent in Patient C.III.1. The following PGRN sequence variations were found: IVS6-2A-->G (A.III.1), R493X (B.II.1), and R433W (C.III.1). IVS6-2A-->G may lead to skipping of exon 7 with consequent frameshift of the coding sequence and premature termination of PGRN translation.


CONCLUSIONS
We have found two PGRN mutations associated with FTD, in affected individuals who are members of families with possible autosomal dominant FTD. A third PGRN sequence variation (R433W) was found in an FTD patient with family history of ALS.
Spina
S
S
Indiana Alzheimer Disease Center, Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Murrell
J R
JR
Huey
E D
ED
Wassermann
E M
EM
Pietrini
P
P
Baraibar
M A
MA
Barbeito
A G
AG
Troncoso
J C
JC
Vidal
R
R
Ghetti
B
B
Grafman
J
J
D000328:Adult; D001483:Base Sequence / Q000235:genetics*; D003704:Dementia / Q000235:genetics* / Q000473:pathology*; D005260:Female; D014644:Genetic Variation / Q000235:genetics*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D000077153:Progranulins
C492314:GRN protein, human; D036341:Intercellular Signaling Peptides and Proteins; D000077153:Progranulins