Characteristics of frontotemporal dementia patients with a Progranulin mutation.
OBJECTIVE
Mutations in the Progranulin gene (PGRN) recently have been discovered to be associated with frontotemporal dementia (FTD) linked to 17q21 without identified MAPT mutations. The range of mutations of PGRN that can result in the FTD phenotype and the clinical presentation of patients with PGRN mutations have yet to be determined.


METHODS
In this study, we examined 84 FTD patients from families not known previously to have illness linked to chromosome 17 for identified PGRN and MAPT mutations and sequenced the coding exons and the flanking intronic regions of PGRN. We compared the prevalence, clinical characteristics, magnetic resonance imaging and 18-fluoro-deoxyglucose positron emission tomography results, and neuropsychological testing of patients with the PGRN R493X mutation with those patients without identified PGRN mutations.


RESULTS
We discovered a new PGRN mutation (R493X) resulting in a stop codon in two patients. This was the only PGRN mutation identified in our sample. The patients with the PGRN R493X mutation had a rapid illness course and had predominant right-sided atrophy and hypometabolism on magnetic resonance imaging and 18-fluoro-deoxyglucose positron emission tomography. The affected father of one of the patients with the PGRN R493X mutation showed frontal and temporal atrophy without neurofibrillary tangles on neuropathological examination.


CONCLUSIONS
Known PGRN and MAPT mutations were rare and of similar prevalence in our sample (2 compared with 1/84). The patients with the PGRN R493X mutation had a clinical presentation comparable with other behavior-predominant FTD patients. The neuropathology of an affected family member of a patient with the PGRN R493X mutation appears not to be Alzheimer's disease.
Huey
Edward D
ED
Cognitive Neuroscience Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1440, USA.
Grafman
Jordan
J
Wassermann
Eric M
EM
Pietrini
Pietro
P
Tierney
Michael C
MC
Ghetti
Bernardino
B
Spina
Salvatore
S
Baker
Matt
M
Hutton
Mike
M
Elder
Joshua W
JW
Berger
Stephen L
SL
Heflin
Kyle A
KA
Hardy
John
J
Momeni
Parastoo
P
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001120:Arginine / Q000235:genetics; D002886:Chromosomes, Human, Pair 17; D004252:DNA Mutational Analysis; D003704:Dementia / Q000000981:diagnostic imaging / Q000235:genetics* / Q000503:physiopathology; D003847:Deoxyglucose / Q000378:metabolism; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008869:Microtubule-Associated Proteins / Q000235:genetics; D008875:Middle Aged; D009154:Mutation; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000379:methods; D016875:tau Proteins / Q000235:genetics
D036341:Intercellular Signaling Peptides and Proteins; C491894:MAP6 protein, human; C054369:MAPT protein, human; D008869:Microtubule-Associated Proteins; D016875:tau Proteins; D001120:Arginine; D003847:Deoxyglucose