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1.  A Multicenter Study of Glucocerebrosidase Mutations in Dementia With Lewy Bodies 
JAMA neurology  2013;70(6):10.1001/jamaneurol.2013.1925.
Importance
While mutations in glucocerebrosidase (GBA1) are associated with an increased risk for Parkinson disease (PD), it is important to establish whether such mutations are also a common risk factor for other Lewy body disorders.
Objective
To establish whether GBA1 mutations are a risk factor for dementia with Lewy bodies (DLB).
Design
We compared genotype data on patients and controls from 11 centers. Data concerning demographics, age at onset, disease duration, and clinical and pathological features were collected when available. We conducted pooled analyses using logistic regression to investigate GBA1 mutation carrier status as predicting DLB or PD with dementia status, using common control subjects as a reference group. Random-effects meta-analyses were conducted to account for additional heterogeneity.
Setting
Eleven centers from sites around the world performing genotyping.
Participants
Seven hundred twenty-one cases met diagnostic criteria for DLB and 151 had PD with dementia. We compared these cases with 1962 controls from the same centers matched for age, sex, and ethnicity.
Main Outcome Measures
Frequency of GBA1 mutations in cases and controls.
Results
We found a significant association between GBA1 mutation carrier status and DLB, with an odds ratio of 8.28 (95% CI, 4.78–14.88). The odds ratio for PD with dementia was 6.48 (95% CI, 2.53–15.37). The mean age at diagnosis of DLB was earlier in GBA1 mutation carriers than in noncarriers (63.5 vs 68.9 years; P<.001), with higher disease severity scores.
Conclusions and Relevance
Mutations in GBA1 are a significant risk factor for DLB. GBA1 mutations likely play an even larger role in the genetic etiology of DLB than in PD, providing insight into the role of glucocerebrosidase in Lewy body disease.
doi:10.1001/jamaneurol.2013.1925
PMCID: PMC3841974  PMID: 23588557
2.  Promoter DNA methylation regulates progranulin expression and is altered in FTLD 
Background
Frontotemporal lobar degeneration (FTLD) is a heterogeneous group of neurodegenerative diseases associated with personality changes and progressive dementia. Loss-of-function mutations in the growth factor progranulin (GRN) cause autosomal dominant FTLD, but so far the pathomechanism of sporadic FTLD is unclear.
Results
We analyzed whether DNA methylation in the GRN core promoter restricts GRN expression and, thus, might promote FTLD in the absence of GRN mutations. GRN expression in human lymphoblast cell lines is negatively correlated with methylation at several CpG units within the GRN promoter. Chronic treatment with the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (DAC) strongly induces GRN mRNA and protein levels. In a reporter assay, CpG methylation blocks transcriptional activity of the GRN core promoter. In brains of FTLD patients several CpG units in the GRN promoter are significantly hypermethylated compared to age-matched healthy controls, Alzheimer and Parkinson patients. These CpG motifs are critical for GRN promoter activity in reporter assays. Furthermore, DNA methyltransferase 3a (DNMT3a) is upregulated in FTLD patients and overexpression of DNMT3a reduces GRN promoter activity and expression.
Conclusion
These data suggest that altered DNA methylation is a novel pathomechanism for FTLD that is potentially amenable to targeted pharmacotherapy.
doi:10.1186/2051-5960-1-16
PMCID: PMC3893557  PMID: 24252647
5-aza-2′-deoxycytidine; DNA methylation; Epigenetics; FTLD; Progranulin
3.  APOE AND ALZHEIMER DISEASE: A MAJOR GENE WITH SEMI-DOMINANT INHERITANCE 
Molecular psychiatry  2011;16(9):903-907.
Apolipoprotein E (APOE) dependent lifetime risks (LTRs) for Alzheimer Disease (AD) are currently not accurately known and odds ratios (ORs) alone are insufficient to assess these risks. We calculated AD lifetime risk in 7,351 cases and 10,132 controls from Caucasian ancestry using Rochester (USA) incidence data. At the age of 85 the LTR of AD without reference to APOE genotype was 11% in males and 14% in females. At the same age, this risk ranged from 51% for APOE44 male carriers to 60% for APOE44 female carriers, and from 23% for APOE34 male carriers to 30% for APOE34 female carriers, consistent with semi-dominant inheritance of a moderately penetrant gene. Using PAQUID (France) incidence data, estimates were globally similar except that at age 85 the LTRs reached 68% and 35 % for APOE 44 and APOE 34 female carriers, respectively. These risks are more similar to those of major genes in Mendelian diseases, such as BRCA1 in breast cancer, than those of low-risk common alleles identified by recent GWAS in complex diseases. In addition, stratification of our data by age- groups clearly demonstrates that APOE4 is a risk factor not only for late- onset but for early- onset AD as well. Together, these results urge a reappraisal of the impact of APOE in Alzheimer disease.
doi:10.1038/mp.2011.52
PMCID: PMC3162068  PMID: 21556001
4.  The genetics and neuropathology of frontotemporal lobar degeneration 
Acta Neuropathologica  2012;124(3):353-372.
Frontotemporal lobar degeneration (FTLD) is a heterogeneous group of disorders characterized by disturbances of behavior and personality and different types of language impairment with or without concomitant features of motor neuron disease or parkinsonism. FTLD is characterized by atrophy of the frontal and anterior temporal brain lobes. Detailed neuropathological studies have elicited proteinopathies defined by inclusions of hyperphosphorylated microtubule-associated protein tau, TAR DNA-binding protein TDP-43, fused-in-sarcoma or yet unidentified proteins in affected brain regions. Rather than the type of proteinopathy, the site of neurodegeneration correlates relatively well with the clinical presentation of FTLD. Molecular genetic studies identified five disease genes, of which the gene encoding the tau protein (MAPT), the growth factor precursor gene granulin (GRN), and C9orf72 with unknown function are most frequently mutated. Rare mutations were also identified in the genes encoding valosin-containing protein (VCP) and charged multivesicular body protein 2B (CHMP2B). These genes are good markers to distinguish underlying neuropathological phenotypes. Due to the complex landscape of FTLD diseases, combined characterization of clinical, imaging, biological and genetic biomarkers is essential to establish a detailed diagnosis. Although major progress has been made in FTLD research in recent years, further studies are needed to completely map out and correlate the clinical, pathological and genetic entities, and to understand the underlying disease mechanisms. In this review, we summarize the current state of the rapidly progressing field of genetic, neuropathological and clinical research of this intriguing condition.
doi:10.1007/s00401-012-1029-x
PMCID: PMC3422616  PMID: 22890575
Frontotemporal lobar degeneration; Proteinopathy; MAPT; GRN; C9orf72; VCP; CHMP2B; Tau; TDP-43; FUS
5.  Recommendations for the treatment of epilepsy in adult patients in general practice in Belgium: an update 
Acta Neurologica Belgica  2012;112(2):119-131.
In 2008, a group of Belgian epilepsy experts published recommendations for antiepileptic drug (AED) treatment of epilepsies in adults and children. Selection of compounds was based on the registration and reimbursement status in Belgium, the level of evidence for efficacy, common daily practice and the personal views and experiences of the authors. In November 2011 the validity of these recommendations was reviewed by the same group of Belgian epilepsy experts who contributed to the preparation of the original paper. The recommendations made in 2008 for initial monotherapy in paediatric patients were still considered to be valid, except for the first choice treatment for childhood absence epilepsy. This update therefore focuses on the treatment recommendations for initial monotherapy and add-on treatment in adult patients. Several other relevant aspects of treatment with AEDs are addressed, including considerations for optimal combination of AEDs (rational polytherapy), pharmacokinetic properties, pharmacodynamic and pharmacokinetic interaction profile, adverse effects, comorbidity, treatment of elderly patients, AED treatment during pregnancy, and generic substitution of AEDs.
doi:10.1007/s13760-012-0070-9
PMCID: PMC3375006  PMID: 22544726
Epilepsy; Antiepileptic drugs; Seizures; Treatment; Recommendations
6.  Both common variations and rare non-synonymous substitutions and small insertion/deletions in CLU are associated with increased Alzheimer risk 
Background
We have followed-up on the recent genome-wide association (GWA) of the clusterin gene (CLU) with increased risk for Alzheimer disease (AD), by performing an unbiased resequencing of all CLU coding exons and regulatory regions in an extended Flanders-Belgian cohort of Caucasian AD patients and control individuals (n = 1930). Moreover, we have replicated genetic findings by targeted resequencing in independent Caucasian cohorts of French (n = 2182) and Canadian (n = 573) origin and by performing meta-analysis combining our data with previous genetic CLU screenings.
Results
In the Flanders-Belgian cohort, we identified significant clustering in exons 5-8 of rare genetic variations leading to non-synonymous substitutions and a 9-bp insertion/deletion affecting the CLU β-chain (p = 0.02). Replicating this observation by targeted resequencing of CLU exons 5-8 in 2 independent Caucasian cohorts of French and Canadian origin identified identical as well as novel non-synonymous substitutions and small insertion/deletions. A meta-analysis, combining the datasets of the 3 cohorts with published CLU sequencing data, confirmed that rare coding variations in the CLU β-chain were significantly enriched in AD patients (ORMH = 1.96 [95% CI = 1.18-3.25]; p = 0.009). Single nucleotide polymorphisms (SNPs) association analysis indicated the common AD risk association (GWA SNP rs11136000, p = 0.013) in the 3 combined datasets could not be explained by the presence of the rare coding variations we identified. Further, high-density SNP mapping in the CLU locus mapped the common association signal to a more 5' CLU region.
Conclusions
We identified a new genetic risk association of AD with rare coding CLU variations that is independent of the 5' common association signal identified in the GWA studies. At this stage the role of these coding variations and their likely effect on the β-chain domain and CLU protein functioning remains unclear and requires further studies.
doi:10.1186/1750-1326-7-3
PMCID: PMC3296573  PMID: 22248099
Alzheimer disease; clusterin gene (CLU); genomic resequencing; non-synonymous substitutions; insertions/deletions; β-chain domain; meta-analysis
7.  TMEM106B is associated with frontotemporal lobar degeneration in a clinically diagnosed patient cohort 
Brain  2011;134(3):808-815.
In a genome-wide association study of frontotemporal lobar degeneration with pathological inclusions of TAR DNA-binding protein, significant association was obtained with three single nucleotide polymorphisms at 7p21.3, in a region encompassing the gene TMEM106B. This study also suggested a potential modifying effect of TMEM106B on disease since the association was strongest in progranulin mutation carriers. Further, the risk effect seemed to correlate with increased TMEM106B expression in patients. In the present study, we sought to replicate these three findings using an independent Flanders–Belgian cohort of primarily clinically diagnosed patients with frontotemporal lobar degeneration (n = 288). We were able to confirm the association with TMEM106B with a P-value of 0.008 for rs1990622, the top marker from the genome-wide association study [odds ratio 0.75 (95% confidence interval 0.61–0.93)]. Further, high-density single nucleotide polymorphism mapping suggested that the association was solely driven by the gene TMEM106B. Homozygous carriers of the TMEM106B protective alleles had a 50% reduced risk of developing frontotemporal lobar degeneration. However, we were unable to detect a modifying effect of the TMEM106B single nucleotide polymorphisms on onset age in progranulin mutation carriers belonging to an extended, clinical and pathological well-documented founder family segregating a progranulin null mutation. Also, we could not observe significant differences in messenger RNA expression between patients and control individuals in lymphoblast cell lines and in brain frontal cortex. In conclusion, we replicated the genetic TMEM106B association in a primarily clinically diagnosed cohort of patients with frontotemporal lobar degeneration from Flanders–Belgium. Additional studies are needed to unravel the molecular role of TMEM106B in disease onset and pathogenesis.
doi:10.1093/brain/awr007
PMCID: PMC3044834  PMID: 21354975
frontotemporal lobar degeneration; TMEM106B; genetic association; risk factor
8.  The CALHM1 P86L polymorphism is a genetic modifier of age at onset in Alzheimer’s disease: a meta-analysis study 
Lambert, Jean-Charles | Sleegers, Kristel | González-Pérez, Antonio | Ingelsson, Martin | Beecham, Gary W | Hiltunen, Mikko | Combarros, Onofre | Bullido, Maria J | Brouwers, Nathalie | Bettens, Karolien | Berr, Claudine | Pasquier, Florence | Richard, Florence | DeKosky, Steven T | Hannequin, Didier | Haines, Jonathan L | Tognoni, Gloria | Fiévet, Nathalie | Dartigues, Jean-François | Tzourio, Christophe | Engelborghs, Sebastiaan | Arosio, Beatrice | Coto, Elicer | De Deyn, Peter | Zompo, Maria Del | Mateo, Ignacio | Boada, Merce | Antunez, Carmen | Lopez-Arrieta, Jesus | Epelbaum, Jacques | Schjeide, Brit-Maren Michaud | Frank-Garcia, Ana | Giedraitis, Vilmentas | Helisalmi, Seppo | Porcellini, Elisa | Pilotto, Alberto | Forti, Paola | Ferri, Raffaele | Delepine, Marc | Zelenika, Diana | Lathrop, Mark | Scarpini, Elio | Siciliano, Gabriele | Solfrizzi, Vincenzo | Sorbi, Sandro | Spalletta, Gianfranco | Ravaglia, Giovanni | Valdivieso, Fernando | Vepsäläinen, Saila | Alvarez, Victoria | Bosco, Paolo | Mancuso, Michelangelo | Panza, Francesco | Nacmias, Benedetta | Bossù, Paola | Hanon, Olivier | Piccardi, Paola | Annoni, Giorgio | Mann, David | Marambaud, Philippe | Seripa, Davide | Galimberti, Daniela | Tanzi, Rudolph E | Bertram, Lars | Lendon, Corinne | Lannfelt, Lars | Licastro, Federico | Campion, Dominique | Pericak-Vance, Margaret A | Soininen, Hilkka | Van Broeckhoven, Christine | Alpérovitch, Annick | Ruiz, Agustin | Kamboh, M Ilyas | Amouyel, Philippe
The only established genetic determinant of non-Mendelian forms of Alzheimer’s disease (AD) is the ε4 allele of the apolipoprotein E gene (APOE). Recently, it has been reported that the P86L polymorphism of the calcium homeostasis modulator 1 gene (CALHM1) is associated with the risk of developing AD. In order to independently assess this association, we performed a meta-analysis of 7,873 AD cases and 13,274 controls of Caucasian origin (from a total of 24 centres in Belgium, Finland, France, Italy, Spain, Sweden, the UK and the USA). Our results indicate that the CALHM1 P86L polymorphism is likely not a genetic determinant of AD but may modulate age at onset by interacting with the effect of the ε4 allele of the APOE gene.
doi:10.3233/JAD-2010-100933
PMCID: PMC2964875  PMID: 20847397
9.  Diagnosis-Independent Alzheimer Disease Biomarker Signature in Cognitively Normal Elderly People 
Archives of neurology  2010;67(8):949-956.
Objective
To identify biomarker patterns typical for Alzheimer disease (AD) in an independent, unsupervised way, without using information on the clinical diagnosis.
Design
Mixture modeling approach.
Setting
Alzheimer’s Disease Neuroimaging Initiative database.
Patients or Other Participants
Cognitively normal persons, patients with AD, and individuals with mild cognitive impairment.
Main Outcome Measures
Cerebrospinal fluid–derived β-amyloid protein 1–42, total tau protein, and phosphorylated tau181P protein concentrations were used as biomarkers on a clinically well-characterized data set. The outcome of the qualification analysis was validated on 2 additional data sets, 1 of which was autopsy confirmed.
Results
Using the US Alzheimer’s Disease Neuroimaging Initiative data set, a cerebrospinal fluid β-amyloid protein 1–42/phosphorylated tau181P biomarker mixture model identified 1 feature linked to AD, while the other matched the “healthy” status. The AD signature was found in 90%, 72%, and 36% of patients in the AD, mild cognitive impairment, and cognitively normal groups, respectively. The cognitively normal group with the AD signature was enriched in apolipoprotein E ε4 allele carriers. Results were validated on 2 other data sets. In 1 study consisting of 68 autopsy-confirmed AD cases, 64 of 68 patients (94% sensitivity) were correctly classified with the AD feature. In another data set with patients (n = 57) with mild cognitive impairment followed up for 5 years, the model showed a sensitivity of 100% in patients progressing to AD.
Conclusions
The mixture modeling approach, totally independent of clinical AD diagnosis, correctly classified patients with AD. The unexpected presence of the AD signature in more than one-third of cognitively normal subjects suggests that AD pathology is active and detectable earlier than has heretofore been envisioned.
doi:10.1001/archneurol.2010.179
PMCID: PMC2963067  PMID: 20697045
10.  FUS pathology defines the majority of tau- and TDP-43-negative frontotemporal lobar degeneration 
Acta neuropathologica  2010;120(1):33-41.
Through an international consortium, we have collected 37 tau- and TAR DNA-binding protein 43 (TDP-43)-negative frontotemporal lobar degeneration (FTLD) cases, and present here the first comprehensive analysis of these cases in terms of neuropathology, genetics, demographics and clinical data. 92% (34/37) had fused in sarcoma (FUS) protein pathology, indicating that FTLD-FUS is an important FTLD subtype. This FTLD-FUS collection specifically focussed on aFTLD-U cases, one of three recently defined subtypes of FTLD-FUS. The aFTLD-U subtype of FTLD-FUS is characterised clinically by behavioural variant frontotemporal dementia (bvFTD) and has a particularly young age of onset with a mean of 41 years. Further, this subtype had a high prevalence of psychotic symptoms (36% of cases) and low prevalence of motor symptoms (3% of cases). We did not find FUS mutations in any aFTLD-U case. To date, the only subtype of cases reported to have ubiquitin-positive but tau-, TDP-43- and FUS-negative pathology, termed FTLD-UPS, is the result of charged multivesicular body protein 2B gene (CHMP2B) mutation. We identified three FTLD-UPS cases, which are negative for CHMP2B mutation, suggesting that the full complement of FTLD pathologies is yet to be elucidated.
doi:10.1007/s00401-010-0698-6
PMCID: PMC2887939  PMID: 20490813
FTLD; FUS; FTLD-UPS; Frontotemporal; FTD
11.  FUS pathology defines the majority of tau- and TDP-43-negative frontotemporal lobar degeneration 
Acta Neuropathologica  2010;120(1):33-41.
Through an international consortium, we have collected 37 tau- and TAR DNA-binding protein 43 (TDP-43)-negative frontotemporal lobar degeneration (FTLD) cases, and present here the first comprehensive analysis of these cases in terms of neuropathology, genetics, demographics and clinical data. 92% (34/37) had fused in sarcoma (FUS) protein pathology, indicating that FTLD-FUS is an important FTLD subtype. This FTLD-FUS collection specifically focussed on aFTLD-U cases, one of three recently defined subtypes of FTLD-FUS. The aFTLD-U subtype of FTLD-FUS is characterised clinically by behavioural variant frontotemporal dementia (bvFTD) and has a particularly young age of onset with a mean of 41 years. Further, this subtype had a high prevalence of psychotic symptoms (36% of cases) and low prevalence of motor symptoms (3% of cases). We did not find FUS mutations in any aFTLD-U case. To date, the only subtype of cases reported to have ubiquitin-positive but tau-, TDP-43- and FUS-negative pathology, termed FTLD-UPS, is the result of charged multivesicular body protein 2B gene (CHMP2B) mutation. We identified three FTLD-UPS cases, which are negative for CHMP2B mutation, suggesting that the full complement of FTLD pathologies is yet to be elucidated.
doi:10.1007/s00401-010-0698-6
PMCID: PMC2887939  PMID: 20490813
FTLD; FUS; FTLD-UPS; Frontotemporal; FTD

Results 1-11 (11)