Publications by authors named "Isabella Fogh"

25 Publications

  • Page 1 of 1

Genome-wide Meta-analysis Finds the ACSL5-ZDHHC6 Locus Is Associated with ALS and Links Weight Loss to the Disease Genetics.

Cell Rep 2020 10;33(4):108323

Centre for Clinical Research, The University of Queensland, Brisbane QLD, Australia; Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane QLD, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane QLD, Australia.

We meta-analyze amyotrophic lateral sclerosis (ALS) genome-wide association study (GWAS) data of European and Chinese populations (84,694 individuals). We find an additional significant association between rs58854276 spanning ACSL5-ZDHHC6 with ALS (p = 8.3 × 10), with replication in an independent Australian cohort (1,502 individuals; p = 0.037). Moreover, B4GALNT1, G2E3-SCFD1, and TRIP11-ATXN3 are identified using a gene-based analysis. ACSL5 has been associated with rapid weight loss, as has another ALS-associated gene, GPX3. Weight loss is frequent in ALS patients and is associated with shorter survival. We investigate the effect of the ACSL5 and GPX3 single-nucleotide polymorphisms (SNPs), using longitudinal body composition and weight data of 77 patients and 77 controls. In patients' fat-free mass, although not significant, we observe an effect in the expected direction (rs58854276: -2.1 ± 1.3 kg/A allele, p = 0.053; rs3828599: -1.0 ± 1.3 kg/A allele, p = 0.22). No effect was observed in controls. Our findings support the increasing interest in lipid metabolism in ALS and link the disease genetics to weight loss in patients.
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http://dx.doi.org/10.1016/j.celrep.2020.108323DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7610013PMC
October 2020

C9orf72 intermediate expansions of 24-30 repeats are associated with ALS.

Acta Neuropathol Commun 2019 07 17;7(1):115. Epub 2019 Jul 17.

Department of Basic and Clinical Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK.

The expansion of a hexanucleotide repeat GGGGCC in C9orf72 is the most common known cause of ALS accounting for ~ 40% familial cases and ~ 7% sporadic cases in the European population. In most people, the repeat length is 2, but in people with ALS, hundreds to thousands of repeats may be observed. A small proportion of people have an intermediate expansion, of the order of 20 to 30 repeats in size, and it remains unknown whether intermediate expansions confer risk of ALS in the same way that massive expansions do. We investigated the association of this intermediate repeat with ALS by performing a meta-analysis of four previously published studies and a new British/Alzheimer's Disease Neuroimaging Initiative dataset of 1295 cases and 613 controls. The final dataset comprised 5071 cases and 3747 controls. Our meta-analysis showed association between ALS and intermediate C9orf72 repeats of 24 to 30 repeats in size (random-effects model OR = 4.2, 95% CI = 1.23-14.35, p-value = 0.02). Furthermore, we showed a different frequency of the repeat between the northern and southern European populations (Fisher's exact test p-value = 5 × 10). Our findings provide evidence for the association between intermediate repeats and ALS (p-value = 2 × 10) with direct relevance for research and clinical practice by showing that an expansion of 24 or more repeats should be considered pathogenic.
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http://dx.doi.org/10.1186/s40478-019-0724-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6637621PMC
July 2019

PON1 is a disease modifier gene in amyotrophic lateral sclerosis: association of the Q192R polymorphism with bulbar onset and reduced survival.

Neurol Sci 2019 Jul 22;40(7):1469-1473. Epub 2019 Mar 22.

Department of Neurology - Stroke Unit and Laboratory of Neuroscience, Istituto Auxologico Italiano, IRCCS, Piazzale Brescia 20, 20149, Milan, Italy.

Introduction: Previous studies have associated single-nucleotide polymorphisms (SNPs) in the gene encoding the detoxifying enzyme paraoxonase 1 (PON1) to the risk of sporadic ALS. Here, we aimed to assess the role of the coding rs662 (Q192R) SNP as a modifier of ALS phenotype.

Materials And Methods: We genotyped a cohort of 409 patients diagnosed with ALS at our Center between 2002 and 2009 (269 males and 140 females; mean age at onset, 58.3 ± 37.5 years).

Results: We found PON1 to be a disease modifier gene in ALS, with the minor allele G associated both with bulbar onset (30.9% vs. 24.6%, p = 0.013) and independently with reduced survival (OR = 1.38, p = 0.012) under a dominant model. No association was found with gender or age at onset.

Discussion: As this SNP is known to modify the detoxifying activity of paraxonase 1 with respect to different substrates as well as other activities of the protein, we hypothesize that the identified association might reflect specific motor neuron vulnerability to certain exogenous toxic substances metabolized less efficiently by the 192R alloenzyme, or to detrimental endogenous pathophysiological processes such as oxidative stress. Further exploration of this possible metabolic susceptibility could deepen our knowledge of ALS pathomechanisms.
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http://dx.doi.org/10.1007/s10072-019-03834-2DOI Listing
July 2019

ALSgeneScanner: a pipeline for the analysis and interpretation of DNA sequencing data of ALS patients.

Amyotroph Lateral Scler Frontotemporal Degener 2019 05 5;20(3-4):207-215. Epub 2019 Mar 5.

c UK Dementia Research Institute, King's College London , London , UK.

Amyotrophic lateral sclerosis (ALS, MND) is a neurodegenerative disease of upper and lower motor neurons resulting in death from neuromuscular respiratory failure, typically within two years of first symptoms. Genetic factors are an important cause of ALS, with variants in more than 25 genes having strong evidence, and weaker evidence available for variants in more than 120 genes. With the increasing availability of next-generation sequencing data, non-specialists, including health care professionals and patients, are obtaining their genomic information without a corresponding ability to analyze and interpret it. Furthermore, the relevance of novel or existing variants in ALS genes is not always apparent. Here we present ALSgeneScanner, a tool that is easy to install and use, able to provide an automatic, detailed, annotated report, on a list of ALS genes from whole-genome sequencing (WGS) data in a few hours and whole exome sequence data in about 1 h on a readily available mid-range computer. This will be of value to non-specialists and aid in the interpretation of the relevance of novel and existing variants identified in DNA sequencing data.
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http://dx.doi.org/10.1080/21678421.2018.1562553DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6567555PMC
May 2019

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene.

Neuron 2018 03;97(6):1268-1283.e6

Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.
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http://dx.doi.org/10.1016/j.neuron.2018.02.027DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5867896PMC
March 2018

Association Between Telomere Length and Risk of Cancer and Non-Neoplastic Diseases: A Mendelian Randomization Study.

JAMA Oncol 2017 May;3(5):636-651

Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.

Importance: The causal direction and magnitude of the association between telomere length and incidence of cancer and non-neoplastic diseases is uncertain owing to the susceptibility of observational studies to confounding and reverse causation.

Objective: To conduct a Mendelian randomization study, using germline genetic variants as instrumental variables, to appraise the causal relevance of telomere length for risk of cancer and non-neoplastic diseases.

Data Sources: Genomewide association studies (GWAS) published up to January 15, 2015.

Study Selection: GWAS of noncommunicable diseases that assayed germline genetic variation and did not select cohort or control participants on the basis of preexisting diseases. Of 163 GWAS of noncommunicable diseases identified, summary data from 103 were available.

Data Extraction And Synthesis: Summary association statistics for single nucleotide polymorphisms (SNPs) that are strongly associated with telomere length in the general population.

Main Outcomes And Measures: Odds ratios (ORs) and 95% confidence intervals (CIs) for disease per standard deviation (SD) higher telomere length due to germline genetic variation.

Results: Summary data were available for 35 cancers and 48 non-neoplastic diseases, corresponding to 420 081 cases (median cases, 2526 per disease) and 1 093 105 controls (median, 6789 per disease). Increased telomere length due to germline genetic variation was generally associated with increased risk for site-specific cancers. The strongest associations (ORs [95% CIs] per 1-SD change in genetically increased telomere length) were observed for glioma, 5.27 (3.15-8.81); serous low-malignant-potential ovarian cancer, 4.35 (2.39-7.94); lung adenocarcinoma, 3.19 (2.40-4.22); neuroblastoma, 2.98 (1.92-4.62); bladder cancer, 2.19 (1.32-3.66); melanoma, 1.87 (1.55-2.26); testicular cancer, 1.76 (1.02-3.04); kidney cancer, 1.55 (1.08-2.23); and endometrial cancer, 1.31 (1.07-1.61). Associations were stronger for rarer cancers and at tissue sites with lower rates of stem cell division. There was generally little evidence of association between genetically increased telomere length and risk of psychiatric, autoimmune, inflammatory, diabetic, and other non-neoplastic diseases, except for coronary heart disease (OR, 0.78 [95% CI, 0.67-0.90]), abdominal aortic aneurysm (OR, 0.63 [95% CI, 0.49-0.81]), celiac disease (OR, 0.42 [95% CI, 0.28-0.61]) and interstitial lung disease (OR, 0.09 [95% CI, 0.05-0.15]).

Conclusions And Relevance: It is likely that longer telomeres increase risk for several cancers but reduce risk for some non-neoplastic diseases, including cardiovascular diseases.
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http://dx.doi.org/10.1001/jamaoncol.2016.5945DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638008PMC
May 2017

ATXN2 trinucleotide repeat length correlates with risk of ALS.

Neurobiol Aging 2017 03 24;51:178.e1-178.e9. Epub 2016 Nov 24.

Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.

We investigated a CAG trinucleotide repeat expansion in the ATXN2 gene in amyotrophic lateral sclerosis (ALS). Two new case-control studies, a British dataset of 1474 ALS cases and 567 controls, and a Dutch dataset of 1328 ALS cases and 691 controls were analyzed. In addition, to increase power, we systematically searched PubMed for case-control studies published after 1 August 2010 that investigated the association between ATXN2 intermediate repeats and ALS. We conducted a meta-analysis of the new and existing studies for the relative risks of ATXN2 intermediate repeat alleles of between 24 and 34 CAG trinucleotide repeats and ALS. There was an overall increased risk of ALS for those carrying intermediate sized trinucleotide repeat alleles (odds ratio 3.06 [95% confidence interval 2.37-3.94]; p = 6 × 10), with an exponential relationship between repeat length and ALS risk for alleles of 29-32 repeats (R = 0.91, p = 0.0002). No relationship was seen for repeat length and age of onset or survival. In contrast to trinucleotide repeat diseases, intermediate ATXN2 trinucleotide repeat expansion in ALS does not predict age of onset but does predict disease risk.
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http://dx.doi.org/10.1016/j.neurobiolaging.2016.11.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5302215PMC
March 2017

C9orf72 expansion differentially affects males with spinal onset amyotrophic lateral sclerosis.

J Neurol Neurosurg Psychiatry 2017 Apr 23;88(4):281. Epub 2016 Sep 23.

Academic Unit of Neurology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland.

Introduction: The repeat expansion has been reported as a negative prognostic factor in amyotrophic lateral sclerosis (ALS). We have examined the prognostic impact of the repeat expansion in European subgroups based on gender and site of onset.

Methods: status and demographic/clinical data from 4925 patients with ALS drawn from 3 prospective ALS registers (Ireland, Italy and the Netherlands), and clinical data sets in the UK and Belgium. Flexible parametric survival models were built including known prognostic factors (age, diagnostic delay and site of onset), gender and the presence of an expanded repeat in These were used to explore the effects of on survival by gender and site of onset. Individual patient data (IPD) meta-analysis was used to estimate HRs for results of particular importance.

Results: 457 (8.95%) of 4925 ALS cases carried the repeat expansion. A meta-analysis of estimated a survival HR of 1.36 (1.18 to 1.57) for those carrying the expansion. Models evaluating interaction between gender and repeat expansions demonstrated that the reduced survival due to expansion was being driven by spinal onset males (HR 1.56 (95% CI 1.25 to 1.96).

Conclusions: This study represents the largest combined analysis of the prognostic characteristics of the expansion. We have shown for the first time that the negative prognostic implication of this variant is driven by males with spinal onset disease, indicating a hitherto unrecognised gender-mediated effect of the variant that requires further exploration.
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http://dx.doi.org/10.1136/jnnp-2016-314093DOI Listing
April 2017

Rare genetic variation in UNC13A may modify survival in amyotrophic lateral sclerosis.

Amyotroph Lateral Scler Frontotemporal Degener 2016 Oct - Nov;17(7-8):593-599. Epub 2016 Sep 1.

a Maurice Wohl Clinical Neuroscience Institute, King's College London, Institute of Psychiatry, Psychology and Neuroscience , London , UK.

Our objective was to identify whether rare genetic variation in amyotrophic lateral sclerosis (ALS) candidate survival genes modifies ALS survival. Candidate genes were selected based on evidence for modifying ALS survival. Each tail of the extreme 1.5% of survival was selected from the UK MND DNA Bank and all samples available underwent whole genome sequencing. A replication set from the Netherlands was used for validation. Sequences of candidate survival genes were extracted and variants passing quality control with a minor allele frequency ≤0.05 were selected for association testing. Analysis was by burden testing using SKAT. Candidate survival genes UNC13A, KIFAP3, and EPHA4 were tested for association in a UK sample comprising 25 short survivors and 25 long survivors. Results showed that only SNVs in UNC13A were associated with survival (p = 6.57 × 10). SNV rs10419420:G > A was found exclusively in long survivors (3/25) and rs4808092:G > A exclusively in short survivors (4/25). These findings were not replicated in a Dutch sample. In conclusion, population specific rare variants of UNC13A may modulate survival in ALS.
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http://dx.doi.org/10.1080/21678421.2016.1213852DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5125285PMC
October 2017

Genome-wide association analyses identify new risk variants and the genetic architecture of amyotrophic lateral sclerosis.

Nat Genet 2016 09 25;48(9):1043-8. Epub 2016 Jul 25.

Department of Molecular Genetics, Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.

To elucidate the genetic architecture of amyotrophic lateral sclerosis (ALS) and find associated loci, we assembled a custom imputation reference panel from whole-genome-sequenced patients with ALS and matched controls (n = 1,861). Through imputation and mixed-model association analysis in 12,577 cases and 23,475 controls, combined with 2,579 cases and 2,767 controls in an independent replication cohort, we fine-mapped a new risk locus on chromosome 21 and identified C21orf2 as a gene associated with ALS risk. In addition, we identified MOBP and SCFD1 as new associated risk loci. We established evidence of ALS being a complex genetic trait with a polygenic architecture. Furthermore, we estimated the SNP-based heritability at 8.5%, with a distinct and important role for low-frequency variants (frequency 1-10%). This study motivates the interrogation of larger samples with full genome coverage to identify rare causal variants that underpin ALS risk.
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http://dx.doi.org/10.1038/ng.3622DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5556360PMC
September 2016

Association of a Locus in the CAMTA1 Gene With Survival in Patients With Sporadic Amyotrophic Lateral Sclerosis.

JAMA Neurol 2016 07;73(7):812-20

Academic Neurology Unit, Department of Neuroscience, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, England.

Importance: Amyotrophic lateral sclerosis (ALS) is a devastating adult-onset neurodegenerative disorder with a poor prognosis and a median survival of 3 years. However, a significant proportion of patients survive more than 10 years from symptom onset.

Objective: To identify gene variants influencing survival in ALS.

Design, Setting, And Participants: This genome-wide association study (GWAS) analyzed survival in data sets from several European countries and the United States that were collected by the Italian Consortium for the Genetics of ALS and the International Consortium on Amyotrophic Lateral Sclerosis Genetics. The study population included 4256 patients with ALS (3125 [73.4%] deceased) with genotype data extended to 7 174 392 variants by imputation analysis. Samples of DNA were collected from January 1, 1993, to December 31, 2009, and analyzed from March 1, 2014, to February 28, 2015.

Main Outcomes And Measures: Cox proportional hazards regression under an additive model with adjustment for age at onset, sex, and the first 4 principal components of ancestry, followed by meta-analysis, were used to analyze data. Survival distributions for the most associated genetic variants were assessed by Kaplan-Meier analysis.

Results: Among the 4256 patients included in the analysis (2589 male [60.8%] and 1667 female [39.2%]; mean [SD] age at onset, 59 [12] years), the following 2 novel loci were significantly associated with ALS survival: at 10q23 (rs139550538; P = 1.87 × 10-9) and in the CAMTA1 gene at 1p36 (rs2412208, P = 3.53 × 10-8). At locus 10q23, the adjusted hazard ratio for patients with the rs139550538 AA or AT genotype was 1.61 (95% CI, 1.38-1.89; P = 1.87 × 10-9), corresponding to an 8-month reduction in survival compared with TT carriers. For rs2412208 CAMTA1, the adjusted hazard ratio for patients with the GG or GT genotype was 1.17 (95% CI, 1.11-1.24; P = 3.53 × 10-8), corresponding to a 4-month reduction in survival compared with TT carriers.

Conclusions And Relevance: This GWAS robustly identified 2 loci at genome-wide levels of significance that influence survival in patients with ALS. Because ALS is a rare disease and prevention is not feasible, treatment that modifies survival is the most realistic strategy. Therefore, identification of modifier genes that might influence ALS survival could improve the understanding of the biology of the disease and suggest biological targets for pharmaceutical intervention. In addition, genetic risk scores for survival could be used as an adjunct to clinical trials to account for the genetic contribution to survival.
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http://dx.doi.org/10.1001/jamaneurol.2016.1114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5556366PMC
July 2016

The role of TREM2 R47H as a risk factor for Alzheimer's disease, frontotemporal lobar degeneration, amyotrophic lateral sclerosis, and Parkinson's disease.

Alzheimers Dement 2015 Dec 30;11(12):1407-1416. Epub 2015 Apr 30.

Department of Clinical Neuroscience, Institute of Psychiatry, King's College London, London, UK.

A rare variant in TREM2 (p.R47H, rs75932628) was recently reported to increase the risk of Alzheimer's disease (AD) and, subsequently, other neurodegenerative diseases, i.e. frontotemporal lobar degeneration (FTLD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Here we comprehensively assessed TREM2 rs75932628 for association with these diseases in a total of 19,940 previously untyped subjects of European descent. These data were combined with those from 28 published data sets by meta-analysis. Furthermore, we tested whether rs75932628 shows association with amyloid beta (Aβ42) and total-tau protein levels in the cerebrospinal fluid (CSF) of 828 individuals with AD or mild cognitive impairment. Our data show that rs75932628 is highly significantly associated with the risk of AD across 24,086 AD cases and 148,993 controls of European descent (odds ratio or OR = 2.71, P = 4.67 × 10(-25)). No consistent evidence for association was found between this marker and the risk of FTLD (OR = 2.24, P = .0113 across 2673 cases/9283 controls), PD (OR = 1.36, P = .0767 across 8311 cases/79,938 controls) and ALS (OR = 1.41, P = .198 across 5544 cases/7072 controls). Furthermore, carriers of the rs75932628 risk allele showed significantly increased levels of CSF-total-tau (P = .0110) but not Aβ42 suggesting that TREM2's role in AD may involve tau dysfunction.
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http://dx.doi.org/10.1016/j.jalz.2014.12.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4627856PMC
December 2015

Heritability of amyotrophic lateral sclerosis.

JAMA Neurol 2014 Dec;71(12):1579-80

King's College London, Institute of Psychiatry, Department of Basic and Clinical Neuroscience, London, England.

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http://dx.doi.org/10.1001/jamaneurol.2014.3493DOI Listing
December 2014

Genetic predisposition to increased blood cholesterol and triglyceride lipid levels and risk of Alzheimer disease: a Mendelian randomization analysis.

PLoS Med 2014 Sep 16;11(9):e1001713. Epub 2014 Sep 16.

King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom.

Background: Although altered lipid metabolism has been extensively implicated in the pathogenesis of Alzheimer disease (AD) through cell biological, epidemiological, and genetic studies, the molecular mechanisms linking cholesterol and AD pathology are still not well understood and contradictory results have been reported. We have used a Mendelian randomization approach to dissect the causal nature of the association between circulating lipid levels and late onset AD (LOAD) and test the hypothesis that genetically raised lipid levels increase the risk of LOAD.

Methods And Findings: We included 3,914 patients with LOAD, 1,675 older individuals without LOAD, and 4,989 individuals from the general population from six genome wide studies drawn from a white population (total n=10,578). We constructed weighted genotype risk scores (GRSs) for four blood lipid phenotypes (high-density lipoprotein cholesterol [HDL-c], low-density lipoprotein cholesterol [LDL-c], triglycerides, and total cholesterol) using well-established SNPs in 157 loci for blood lipids reported by Willer and colleagues (2013). Both full GRSs using all SNPs associated with each trait at p<5×10-8 and trait specific scores using SNPs associated exclusively with each trait at p<5 × 10-8 were developed. We used logistic regression to investigate whether the GRSs were associated with LOAD in each study and results were combined together by meta-analysis. We found no association between any of the full GRSs and LOAD (meta-analysis results: odds ratio [OR]=1.005, 95% CI 0.82-1.24, p = 0.962 per 1 unit increase in HDL-c; OR=0.901, 95% CI 0.65-1.25, p=0.530 per 1 unit increase in LDL-c; OR=1.104, 95% CI 0.89-1.37, p=0.362 per 1 unit increase in triglycerides; and OR=0.954, 95% CI 0.76-1.21, p=0.688 per 1 unit increase in total cholesterol). Results for the trait specific scores were similar; however, the trait specific scores explained much smaller phenotypic variance.

Conclusions: Genetic predisposition to increased blood cholesterol and triglyceride lipid levels is not associated with elevated LOAD risk. The observed epidemiological associations between abnormal lipid levels and LOAD risk could therefore be attributed to the result of biological pleiotropy or could be secondary to LOAD. Limitations of this study include the small proportion of lipid variance explained by the GRS, biases in case-control ascertainment, and the limitations implicit to Mendelian randomization studies. Future studies should focus on larger LOAD datasets with longitudinal sampled peripheral lipid measures and other markers of lipid metabolism, which have been shown to be altered in LOAD. Please see later in the article for the Editors' Summary.
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http://dx.doi.org/10.1371/journal.pmed.1001713DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4165594PMC
September 2014

Alleles that increase risk for type 2 diabetes mellitus are not associated with increased risk for Alzheimer's disease.

Neurobiol Aging 2014 Dec 24;35(12):2883.e3-2883.e10. Epub 2014 Jul 24.

King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, UK.

Although epidemiological studies suggest that type 2 diabetes mellitus (T2DM) increases the risk of late-onset Alzheimer's disease (LOAD), the biological basis of this relationship is not well understood. The aim of this study was to examine the genetic comorbidity between the 2 disorders and to investigate whether genetic liability to T2DM, estimated by a genotype risk scores based on T2DM associated loci, is associated with increased risk of LOAD. This study was performed in 2 stages. In stage 1, we combined genotypes for the top 15 T2DM-associated polymorphisms drawn from approximately 3000 individuals (1349 cases and 1351 control subjects) with extracted and/or imputed data from 6 genome-wide studies (>10,000 individuals; 4507 cases, 2183 controls, 4989 population controls) to form a genotype risk score and examined if this was associated with increased LOAD risk in a combined meta-analysis. In stage 2, we investigated the association of LOAD with an expanded T2DM score made of 45 well-established variants drawn from the 6 genome-wide studies. Results were combined in a meta-analysis. Both stage 1 and stage 2 T2DM risk scores were not associated with LOAD risk (odds ratio = 0.988; 95% confidence interval, 0.972-1.004; p = 0.144 and odds ratio = 0.993; 95% confidence interval, 0.983-1.003; p = 0.149 per allele, respectively). Contrary to expectation, genotype risk scores based on established T2DM candidates were not associated with increased risk of LOAD. The observed epidemiological associations between T2DM and LOAD could therefore be a consequence of secondary disease processes, pleiotropic mechanisms, and/or common environmental risk factors. Future work should focus on well-characterized longitudinal cohorts with extensive phenotypic and genetic data relevant to both LOAD and T2DM.
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http://dx.doi.org/10.1016/j.neurobiolaging.2014.07.023DOI Listing
December 2014

C9orf72 and UNC13A are shared risk loci for amyotrophic lateral sclerosis and frontotemporal dementia: a genome-wide meta-analysis.

Ann Neurol 2014 Jul 27;76(1):120-33. Epub 2014 Jun 27.

Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, the Netherlands.

Objective: Substantial clinical, pathological, and genetic overlap exists between amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). TDP-43 inclusions have been found in both ALS and FTD cases (FTD-TDP). Recently, a repeat expansion in C9orf72 was identified as the causal variant in a proportion of ALS and FTD cases. We sought to identify additional evidence for a common genetic basis for the spectrum of ALS-FTD.

Methods: We used published genome-wide association studies data for 4,377 ALS patients and 13,017 controls, and 435 pathology-proven FTD-TDP cases and 1,414 controls for genotype imputation. Data were analyzed in a joint meta-analysis, by replicating topmost associated hits of one disease in the other, and by using a conservative rank products analysis, allocating equal weight to ALS and FTD-TDP sample sizes.

Results: Meta-analysis identified 19 genome-wide significant single nucleotide polymorphisms (SNPs) in C9orf72 on chromosome 9p21.2 (lowest p = 2.6 × 10(-12) ) and 1 SNP in UNC13A on chromosome 19p13.11 (p = 1.0 × 10(-11) ) as shared susceptibility loci for ALS and FTD-TDP. Conditioning on the 9p21.2 genotype increased statistical significance at UNC13A. A third signal, on chromosome 8q24.13 at the SPG8 locus coding for strumpellin (p = 3.91 × 10(-7) ) was replicated in an independent cohort of 4,056 ALS patients and 3,958 controls (p = 0.026; combined analysis p = 1.01 × 10(-7) ).

Interpretation: We identified common genetic variants in C9orf72, but in addition in UNC13A that are shared between ALS and FTD. UNC13A provides a novel link between ALS and FTD-TDP, and identifies changes in neurotransmitter release and synaptic function as a converging mechanism in the pathogenesis of ALS and FTD-TDP.
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http://dx.doi.org/10.1002/ana.24198DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4137231PMC
July 2014

Analysis of the KIFAP3 gene in amyotrophic lateral sclerosis: a multicenter survival study.

Neurobiol Aging 2014 Oct 19;35(10):2420.e13-4. Epub 2014 Apr 19.

The Institute of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden.

Sporadic amyotrophic lateral sclerosis is a multifactorial disease of environmental and genetic origin. In a previous large multicenter genome wide study, common genetic variation in the Kinesin-Associated Protein 3 (KIFAP3) gene (rs1541160) was reported to have a significant effect on survival in amyotrophic lateral sclerosis patients. However, this could not be replicated in 3 smaller independent cohorts. We conducted a large multicenter multivariate survival analysis (n = 2362) on the effect of genetic variation in rs1541160. The previously reported beneficial genotype did not show a significant improvement in survival in this patient group.
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http://dx.doi.org/10.1016/j.neurobiolaging.2014.04.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5496711PMC
October 2014

A genome-wide association meta-analysis identifies a novel locus at 17q11.2 associated with sporadic amyotrophic lateral sclerosis.

Hum Mol Genet 2014 Apr 20;23(8):2220-31. Epub 2013 Nov 20.

Department of Neuroscience.

Identification of mutations at familial loci for amyotrophic lateral sclerosis (ALS) has provided novel insights into the aetiology of this rapidly progressing fatal neurodegenerative disease. However, genome-wide association studies (GWAS) of the more common (∼90%) sporadic form have been less successful with the exception of the replicated locus at 9p21.2. To identify new loci associated with disease susceptibility, we have established the largest association study in ALS to date and undertaken a GWAS meta-analytical study combining 3959 newly genotyped Italian individuals (1982 cases and 1977 controls) collected by SLAGEN (Italian Consortium for the Genetics of ALS) together with samples from Netherlands, USA, UK, Sweden, Belgium, France, Ireland and Italy collected by ALSGEN (the International Consortium on Amyotrophic Lateral Sclerosis Genetics). We analysed a total of 13 225 individuals, 6100 cases and 7125 controls for almost 7 million single-nucleotide polymorphisms (SNPs). We identified a novel locus with genome-wide significance at 17q11.2 (rs34517613 with P = 1.11 × 10(-8); OR 0.82) that was validated when combined with genotype data from a replication cohort (P = 8.62 × 10(-9); OR 0.833) of 4656 individuals. Furthermore, we confirmed the previously reported association at 9p21.2 (rs3849943 with P = 7.69 × 10(-9); OR 1.16). Finally, we estimated the contribution of common variation to heritability of sporadic ALS as ∼12% using a linear mixed model accounting for all SNPs. Our results provide an insight into the genetic structure of sporadic ALS, confirming that common variation contributes to risk and that sufficiently powered studies can identify novel susceptibility loci.
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http://dx.doi.org/10.1093/hmg/ddt587DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3959809PMC
April 2014

C9ORF72 repeat expansion in a large Italian ALS cohort: evidence of a founder effect.

Neurobiol Aging 2012 Oct 4;33(10):2528.e7-14. Epub 2012 Jul 4.

Department of Neurology and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Milan, Italy.

A hexanucleotide repeat expansion (RE) in C9ORF72 gene was recently reported as the main cause of amyotrophic lateral sclerosis (ALS) and cases with frontotemporal dementia. We screened C9ORF72 in a large cohort of 259 familial ALS, 1275 sporadic ALS, and 862 control individuals of Italian descent. We found RE in 23.9% familial ALS, 5.1% sporadic ALS, and 0.2% controls. Two cases carried the RE together with mutations in other ALS-associated genes. The phenotype of RE carriers was characterized by bulbar-onset, shorter survival, and association with cognitive and behavioral impairment. Extrapyramidal and cerebellar signs were also observed in few patients. Genotype data revealed that 95% of RE carriers shared a restricted 10-single nucleotide polymorphism haplotype within the previously reported 20-single nucleotide polymorphism risk haplotype, detectable in only 27% of nonexpanded ALS cases and in 28% of controls, suggesting a common founder with cohorts of North European ancestry. Although C9ORF72 RE segregates with disease, the identification of RE both in controls and in patients carrying additional pathogenic mutations suggests that penetrance and phenotypic expression of C9ORF72 RE may depend on additional genetic risk factors.
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http://dx.doi.org/10.1016/j.neurobiolaging.2012.06.008DOI Listing
October 2012

Chromosome 9p21 in sporadic amyotrophic lateral sclerosis in the UK and seven other countries: a genome-wide association study.

Lancet Neurol 2010 Oct;9(10):986-94

King's College London, Medical Research Council Centre for Neurodegeneration Research, Department of Clinical Neuroscience, Institute of Psychiatry, London, UK.

Background: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of motor neurons that results in progressive weakness and death from respiratory failure, commonly within about 3 years. Previous studies have shown association of a locus on chromosome 9p with ALS and linkage with ALS-frontotemporal dementia. We aimed to test whether this genomic region is also associated with ALS in an independent set of UK samples, and to identify risk factors associated with ALS in a further genome-wide association study that combined data from the independent analysis with those from other countries.

Methods: We collected samples from patients with sporadic ALS from 20 UK hospitals and obtained UK control samples from the control groups of the Depression Case Control study, the Bipolar Affective Case Control Study, and the British 1958 birth cohort DNA collection. Genotyping of DNA in this independent analysis was done with Illumina HumanHap550 BeadChips. We then undertook a joint genome-wide analysis that combined data from the independent set with published data from the UK, USA, Netherlands, Ireland, Italy, France, Sweden, and Belgium. The threshold for significance was p=0·05 in the independent analysis, because we were interested in replicating a small number of previously reported associations, whereas the Bonferroni-corrected threshold for significance in the joint analysis was p=2·20×10(-7)

Findings: After quality control, samples were available from 599 patients and 4144 control individuals in the independent set. In this analysis, two single nucleotide polymorphisms in a locus on chromosome 9p21.2 were associated with ALS: rs3849942 (p=2·22×10(-6); odds ratio [OR] 1·39, 95% CI 1·21-1·59) and rs2814707 (p=3·32×10(-6); 1·38, 1·20-1·58). In the joint analysis, which included samples from 4312 patients with ALS and 8425 control individuals, rs3849942 (p=4·64×10(-10); OR 1·22, 95% CI 1·15-1·30) and rs2814707 (p=4·72×10(-10); 1·22, 1·15-1·30) were associated with ALS.

Interpretation: We have found strong evidence of a genetic association of two single nucleotide polymorphisms on chromosome 9 with sporadic ALS, in line with findings from previous independent GWAS of ALS and linkage studies of ALS-frontotemporal dementia. Our findings together with these earlier findings suggest that genetic variation at this locus on chromosome 9 causes sporadic ALS and familial ALS-frontotemporal dementia. Resequencing studies and then functional analysis should be done to identify the defective gene.
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http://dx.doi.org/10.1016/S1474-4422(10)70197-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257853PMC
October 2010

No association of DPP6 with amyotrophic lateral sclerosis in an Italian population.

Neurobiol Aging 2011 May 13;32(5):966-7. Epub 2009 Jun 13.

MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, UK.

We have attempted to replicate a recently reported association of polymorphism rs10260404, in the Dipeptidyl-peptidase 6 gene (DPP6), with susceptibility to amyotrophic lateral sclerosis (ALS) in a large independent Italian cohort of 904 cases and 1036 controls. Minor allele frequency was 0.38 in cases and 0.39 in controls and no evidence of association with ALS was observed (P=0.638). Our negative results agree with those recently reported in additional Polish and Italian cohorts.
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http://dx.doi.org/10.1016/j.neurobiolaging.2009.05.014DOI Listing
May 2011

Association study on glutathione S-transferase omega 1 and 2 and familial ALS.

Amyotroph Lateral Scler 2008 Apr;9(2):81-4

Department of Neurology, Institute of Psychiatry, King's College London, London, UK.

Glutathione S-transferase omega 1 and 2 (GSTO1 and 2) protect from oxidative stress, a possible pathogenic mechanism underlying the pathogenesis of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and Alzheimer's disease. Significant association of age of onset in Alzheimer's patients with GSTO1 and 2 had recently been identified, suggesting a possibly similar association with ALS. In this study 12 Hapmap tagged SNPs in GSTO1 and 2 were genotyped in 251 Caucasian British, Australian and Swedish familial ALS (FALS) cases. No association was found for age of onset and survival of FALS in the British and Australian patients. In the Swedish patients, association for age of onset was found with several SNPs (p = 0.003-0.048). These results suggest a possible effect of the GSTO1 and 2 locus on age of onset of FALS.
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http://dx.doi.org/10.1080/17482960701702553DOI Listing
April 2008

Stem cell therapy for neurodegenerative diseases: the issue of transdifferentiation.

Stem Cells Dev 2004 Feb;13(1):121-31

Department of Neurology and Laboratory of Neuroscience, Dino Ferrari Center, University of Milan Medical School, IRCCS Istituto Auxologico Italiano, Milan, Italy.

In the past few years research on stem cells has exploded as a tool to develop potential therapies to treat incurable neurodegenerative diseases. Stem cell transplantation has been effective in several animal models, but the underlying restorative mechanisms are still unknown. Several events such as cell fusion, neurotrophic factor release, endogenous stem cell proliferation, and transdifferentiation (adult cell acquisition of new unexpected identities) may explain therapeutic success, in addition to replacement of lost cells. This issue needs to be clarified further to maximize the potential for effective therapies. Preliminary stem transplantation trials have already been performed for some neurodegenerative diseases. There is no effective pharmacological treatment for amyotrophic lateral sclerosis, but recent preliminary data both in experimental and clinical settings have targeted it as an ideal candidate disease for the development of stem cell therapy in humans. This review summarizes recent advances gained in stem cell research applied to neurodegenerative diseases with a special emphasis to the criticisms put forward.
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http://dx.doi.org/10.1089/154732804773099326DOI Listing
February 2004

Stem cells in the treatment of amyotrophic lateral sclerosis (ALS).

Amyotroph Lateral Scler Other Motor Neuron Disord 2002 Dec;3(4):173-81

Department of Neurology, Laboratory of Neuroscience, Dino Ferrari Center, University of Milan Medical School, IRCCS Istituto Auxologico Italiano, Via Spagnoletto 3, 1-20149 Milano, Italy.

Until fairly recently, interest in stem cells was restricted to neurobiology studies on the principles of embryonic development. This situation has changed rapidly in the last few years when neuronal stems and precursors were isolated in vitro, thus allowing expansion and controlled differentiation of selective populations of neuronal cells. This theoretically unlimited reserve would then supply specific cells for transplantation in diseases characterized by widespread degeneration of selective cell populations as motor neurons in Amyotrophic Lateral Sclerosis (ALS). The recent evidence of cell transdifferentiation has further amplified the potential therapeutic use of stem cells. Stem cell technology is at an early stage but the desperate need for a therapy in ALS patients may legitimize clinical trials in absence of conclusive scientific evidence. This paper discusses the premises for stem cell therapy in ALS.
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http://dx.doi.org/10.1080/146608202760839001DOI Listing
December 2002