Phenotypic variability associated with progranulin haploinsufficiency in patients with the common 1477C→T (Arg493X) mutation: an international initiative

Rosa Rademakers, Matt Baker, Jennifer Gass, Jennifer Adamson, Edward D. Huey, Parastoo Momeni, Salvatore Spina, Giovanni Coppola, Anna M. Karydas, Heather Stewart, Nancy Johnson, Ging Yuek Hsiung, Brendan Kelley, Karen Kuntz, Ellen Steinbart, Elisabeth Mc Carty Wood, Chang En Yu, Keith Josephs, Eric Sorenson, Kyle B. WomackSandra Weintraub, Stuart M. Pickering-Brown, Peter R. Schofield, William S. Brooks, Vivianna M. Van Deerlin, Julie Snowden, Christopher M. Clark, Andrew Kertesz, Kevin Boylan, Bernardino Ghetti, David Neary, Gerard D. Schellenberg, Thomas G. Beach, Marsel Mesulam, David Mann, Jordan Grafman, Ian R. Mackenzie, Howard Feldman, Thomas Bird, Ron Petersen, David Knopman, Bradley Boeve, Dan H. Geschwind, Bruce Miller, Zbigniew Wszolek, Carol Lippa, Eileen H. Bigio, Dennis Dickson, Neill Graff-Radford, Mike Hutton

Research output: Contribution to journalArticlepeer-review

177 Scopus citations

Abstract

Background: The progranulin gene (GRN) is mutated in 5-10% of patients with frontotemporal lobar degeneration (FTLD) and in about 20% of patients with familial FTLD. The most common mutation in GRN is Arg493X. We aimed to establish the contribution of this mutation to FTLD and related disorders. Methods: We measured the frequency of Arg493X in 3405 unrelated patients with various neurodegenerative diseases using Taqman single-nucleotide polymorphism (SNP) genotyping. Clinicopathological characterisation and shared haplotype analysis were done for 30 families with FTLD who carry Arg493X. To investigate the effect of potential modifying loci, we did linear regression analyses with onset age as the covariate for GRN variants, for genotypes of the apolipoprotein E gene (APOE), and for haplotypes of the microtubule-associated protein tau gene (MAPT). Findings: Of 731 patients with FTLD, 16 (2%) carried Arg493X. This mutation was not detected in 2674 patients who did not have FTLD. In 37 patients with Arg493X from 30 families with FTLD, clinical diagnoses included frontotemporal dementia, primary progressive aphasia, corticobasal syndrome, and Alzheimer's disease. Range of onset age was 44-69 years. In all patients who came to autopsy (n=13), the pathological diagnosis was FTLD with neuronal inclusions that contained TAR DNA-binding protein or ubiquitin, but not tau. Neurofibrillary tangle pathology in the form of Braak staging correlated with overall neuropathology in the Arg493X carriers. Haplotype analyses suggested that Arg493X arose twice, with a single founder for 27 families. Linear regression analyses suggested that patients with SNP rs9897528 on their wild-type GRN allele have delayed symptom onset. Onset ages were not associated with the MAPT H1 or H2 haplotypes or APOE genotypes, but early memory deficits were associated with the presence of an APOE ε4 allele. Interpretation: Clinical heterogeneity is associated with GRN haploinsufficiency, and genetic variability on the wild-type GRN allele might have a role in the age-related disease penetrance of GRN mutations.

Original languageEnglish (US)
Pages (from-to)857-868
Number of pages12
JournalLancet Neurology
Volume6
Issue number10
DOIs
StatePublished - Oct 2007

ASJC Scopus subject areas

  • Clinical Neurology

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