Lee, V.M.Y.

Identification of common variants influencing risk of the tauopathy progressive supranuclear palsy (Article)

2011-07-01T00:00:00Z

Progressive supranuclear palsy (PSP) is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common of which is Alzheimer's disease. Environmental causes of tauopathies include repetitive head trauma associated with some sports. To identify common genetic variation contributing to risk for tauopathies, we carried out a genome-wide association study of 1,114 individuals with PSP (cases) and 3,247 controls (stage 1) followed by a second stage in which we genotyped 1,051 cases and 3,560 controls for the stage 1 SNPs that yielded P ≤ 10-3. We found significant previously unidentified signals (P < 5 × 10-8) associated with PSP risk at STX6, EIF2AK3 and MOBP. We confirmed two independent variants in MAPT affecting risk for PSP, one of which influences MAPT brain expression. The genes implicated encode proteins for vesicle-membrane fusion at the Golgi-endosomal interface, for the endoplasmic reticulum unfolded protein response and for a myelin structural component.

Genetic and clinical features of progranulin-associated frontotemporal lobar degeneration (Article)

2011-04-01T00:00:00Z

Objective: To assess the relative frequency of unique mutations and their associated characteristics in 97 individuals with mutations in progranulin (GRN), an important cause of frontotemporal lobar degeneration (FTLD). Participants and Design: A 46-site International Frontotemporal Lobar Degeneration Collaboration was formed to collect cases of FTLD with TAR DNA-binding protein of 43-kDa (TDP-43)-positive inclusions (FTLD-TDP). We identified 97 individuals with FTLD-TDP with pathogenic GRN mutations (GRN+ FTLD-TDP), assessed their genetic and clinical characteristics, and compared them with 453 patients with FTLD-TDP in which GRN mutations were excluded (GRN- FTLD-TDP). No patients were known to be related. Neuropathologic characteristics were confirmed as FTLD-TDP in 79 of the 97 GRN+ FTLDTDP cases and all of the GRN- FTLD-TDP cases. Results: Age at onset of FTLD was younger in patients with GRN+ FTLD-TDP vs GRN- FTLD-TDP (median, 58.0 vs 61.0 years; P<.001), as was age at death (median, 65.5 vs 69.0 years; P<.001). Concomitant motor neuron disease was much less common in GRN+ FTLDTDP vs GRN- FTLD-TDP (5.4% vs 26.3%; P<.001). Fifty different GRN mutations were observed, including 2 novel mutations: c.139delG (p.D47TfsX7) and c.378C>A (p.C126X). The 2 most common GRN mutations were c.1477C>T (p.R493X, found in 18 patients, representing 18.6% of GRN cases) and c.26C>A (p.A9D, found in 6 patients, representing 6.2% of cases). Patients with the c.1477C>T mutation shared a haplotype on chromosome 17; clinically, they resembled patients with other GRN mutations. Patients with the c.26C>A mutation appeared to have a younger age at onset of FTLD and at death and more parkinsonian features than those with other GRN mutations. Conclusion: GRN+ FTLD-TDP differs in key features from GRN- FTLD-TDP.

Common variants at 7p21 are associated with frontotemporal lobar degeneration with TDP-43 inclusions (Article)

2010-03-01T00:00:00Z

Frontotemporal lobar degeneration (FTLD) is the second most common cause of presenile dementia. The predominant neuropathology is FTLD with TAR DNA-binding protein (TDP-43) inclusions (FTLD-TDP). FTLD-TDP is frequently familial, resulting from mutations in GRN (which encodes progranulin). We assembled an international collaboration to identify susceptibility loci for FTLD-TDP through a genome-wide association study of 515 individuals with FTLD-TDP. We found that FTLD-TDP associates with multiple SNPs mapping to a single linkage disequilibrium block on 7p21 that contains TMEM106B. Three SNPs retained genome-wide significance following Bonferroni correction (top SNP rs1990622, P = 1.08 × 10 11; odds ratio, minor allele (C) 0.61, 95% CI 0.53-0.71). The association replicated in 89 FTLD-TDP cases (rs1990622; P = 2 × 10 4). TMEM106B variants may confer risk of FTLD-TDP by increasing TMEM106B expression. TMEM106B variants also contribute to genetic risk for FTLD-TDP in individuals with mutations in GRN. Our data implicate variants in TMEM106B as a strong risk factor for FTLD-TDP, suggesting an underlying pathogenic mechanism.

Survival profiles of patients with frontotemporal dementia and motor neuron disease (Article)

2009-11-01T00:00:00Z

Background: Frontotemporal dementia and amyotrophic lateral sclerosis are neurodegenerative diseases associated with TAR DNA-binding protein 43- and ubiquitin-immunoreactive pathologic lesions. Objective: To determine whether survival is influenced by symptom of onset in patients with frontotemporal dementia and amyotrophic lateral sclerosis. Design, Setting, and Patients: Retrospective review of patients with both cognitive impairment and motor neuron disease consecutively evaluated at 4 academic medical centers in 2 countries. Main Outcome Measures: Clinical phenotypes and survival patterns of patients. Results: A total of 87 patients were identified, including 60 who developed cognitive symptoms first, 19 who developed motor symptoms first, and 8 who had simultaneous onset of cognitive and motor symptoms. Among the 59 deceased patients, we identified 2 distinct subgroups of patients according to survival. Long-term survivors had cognitive onset and delayed emergence of motor symptoms after a long monosymptomatic phase and had significantly longer survival than the typical survivors (mean, 67.5 months vs 28.2 months, respectively; P<.001). Typical survivors can have simultaneous or discrete onset of cognitive and motor symptoms, and the simultaneous-onset patients had shorter survival (mean, 19.2 months) than those with distinct cognitive or motor onset (mean, 28.6 months) (P=.005). Conclusions: Distinct patterns of survival profiles exist in patients with frontotemporal dementia and motor neuron disease, and overall survival may depend on the relative timing of the emergence of secondary symptoms.