Risk Of ALS Research Articles

Harnessing transcriptomic signals for amyotrophic lateral sclerosis to identify novel drugs and enhance risk prediction

IntroductionAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. This study integrates common genetic association results from the latest ALS genome-wide association study (GWAS) summary statistics with functional genomic annotations with the aim of providing mechanistic insights into ALS risk loci, inferring drug repurposing opportunities, and enhancing prediction of ALS risk and clinical characteristics. MethodsGenes associated with ALS were identified using GWAS summary statistic methodology including SuSiE SNP-based fine-mapping, and transcriptome- and proteome-wide association study (TWAS/PWAS) analyses. Using several approaches, gene associations were integrated with the DrugTargetor drug-gene interaction database to identify drugs that could be repurposed for the treatment of ALS. Furthermore, ALS gene associations from TWAS were combined with observed blood expression in two external ALS case-control datasets to calculate polytranscriptomic scores and evaluate their utility for prediction of ALS risk and clinical characteristics, including site of onset, age at onset, and survival. ResultsSNP-based fine-mapping, TWAS and PWAS identified 118 genes associated with ALS, with TWAS and PWAS providing novel mechanistic insights. Drug repurposing analyses identified six drugs significantly enriched for interactions with ALS associated genes, though directionality could not be determined. Additionally, drug class enrichment analysis showed gene signatures linked to calcium channel blockers may reduce ALS risk, whereas antiepileptic drugs may increase ALS risk. Across the two observed expression target samples, ALS polytranscriptomic scores significantly predicted ALS risk (R2 = 5.1 %; p-value = 3.2 × 10−27) and clinical characteristics. ConclusionsFunctionally-informed analyses of ALS GWAS summary statistics identified novel mechanistic insights into ALS aetiology, highlighted several therapeutic research avenues, and enabled statistically significant prediction of ALS risk.

Clonal hematopoiesis of indeterminate potential and risk of neurodegenerative diseases.

Little is known regarding the association between clonal hematopoiesis of indeterminate potential (CHIP) and risk of neurodegenerative diseases. To estimate the risk of neurodegenerative diseases among individuals with CHIP. We conducted a community-based cohort study based on UK Biobank and used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of any neurodegenerative disease, subtypes of neurodegenerative diseases (including primary neurodegenerative diseases, vascular neurodegenerative diseases, and other neurodegenerative diseases), and specific diagnoses of neurodegenerative diseases (i.e., amyotrophic lateral sclerosis [ALS], Alzheimer's disease [AD], and Parkinson's disease [PD]) associated with CHIP. We identified 14,440 individuals with CHIP and 450,907 individuals without CHIP. Individuals with CHIP had an increased risk of any neurodegenerative disease (HR 1.10, 95% CI: 1.01-1.19). We also observed a statistically significantly increased risk for vascular neurodegenerative diseases (HR 1.31, 95% CI 1.05-1.63) and ALS (HR 1.50, 95% CI 1.05-2.15). An increased risk was also noted for other neurodegenerative diseases (HR 1.13, 95% CI 0.97-1.32), although not statistically significant. Null association was noted for primary neurodegenerative diseases (HR 1.06, 95% CI 0.96-1.17), AD (HR 1.04, 95% CI 0.88-1.23), and PD (HR 1.02, 95% CI 0.86-1.21). The risk increase in any neurodegenerative disease was mainly observed for DNMT3A-mutant CHIP, ASXL1-mutant CHIP, or SRSF2-mutant CHIP. Individuals with CHIP were at an increased risk of neurodegenerative diseases, primarily vascular neurodegenerative diseases and ALS, but potentially also other neurodegenerative diseases. These findings suggest potential shared mechanisms between CHIP and neurodegenerative diseases.

Response to “assessment of risk of ALS conferred by the GGGGCC hexanucleotide expansion in C9orf72 among first-degree relatives of patients with ALS carrying the repeat expansion”

Response to “assessment of risk of ALS conferred by the GGGGCC hexanucleotide expansion in C9orf72 among first-degree relatives of patients with ALS carrying the repeat expansion”

Mutations in the tail and rod domains of the neurofilament heavy-chain gene increase the risk of ALS.

Neurofilament heavy-chain gene (NEFH) variants are associated with multiple neurodegenerative diseases, however, their relationship with ALS has not been robustly explored. Still, NEFH is commonly included in genetic screening panels worldwide. We therefore aimed to determine if NEFH variants modify ALS risk. Genetic data of 11,130 people with ALS and 7,416 controls from the literature and Project MinE were analysed. We performed meta-analyses of published case-control studies reporting NEFH variants, and variant analysis of NEFH in Project MinE whole-genome sequencing data. Fixed-effects meta-analysis found that rare (MAF <1%) missense variants in the tail domain of NEFH increase ALS risk (OR 4.55, 95% CI 2.13-9.71, p < 0.0001). In Project MinE, ultrarare NEFH variants increased ALS risk (OR 1.37 95% CI 1.14-1.63, p = 0.0007), with rod domain variants (mostly intronic) appearing to drive the association (OR 1.45 95% CI 1.18-1.77, pMadsen-Browning = 0.0007, pSKAT-O = 0.003). While in the tail domain, ultrarare (MAF <0.1%) pathogenic missense variants were also associated with higher risk of ALS (OR 1.94, 95% CI 0.86-4.37, pMadsen-Browning = 0.039), supporting the meta-analysis results. Finally, several tail in-frame deletions were also found to affect disease risk, however, both protective and pathogenic deletions were found in this domain, highlighting an intricate architecture that requires further investigation. We showed that NEFH tail missense and in-frame deletion variants, and intronic rod variants are risk factors for ALS. However, they are not variants of large effect, and their functional impact needs to be clarified in further studies. Therefore, their inclusion in routine genetic screening panels should be reconsidered.

Evaluation of carotid Intima-Media Thickness (IMT) in amyotrophic lateral sclerosis disease using ultrasonography

BackgroundAmyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease with multi-mechanisms as; inflammation, oxidative stress, glutamate excitotoxicity, protein aggregation, etc. This study aimed to evaluate the carotid Intima-Media Thickness (IMT) in ALS and healthy groups, as a possible indicator of these mechanisms. Methods42 patients with ALS along with 53 normal age and body mass index (BMI) matched participants were recruited from the Firoozgar hospital. Carotid IMT values of the participants were measured using B-mode ultrasonography. Using Pearson correlation and logistic regression adjusting with age, BMI, and gender, the IMT values were assessed. ResultsThe mean right and left carotid IMT values of the ALS patients (0.66 ± 0.09) were significantly higher than normal participants (0.45 ± 0.10) (p < 0.001). In addition, the IMT values were highly correlated with the age (r = 0.632; p < 0.001) and the age of ALS onset (r = 0.595; p < 0.001), in contrast to the BMI. Moreover, the higher value of IMT was associated with an increasing risk of ALS with an odd ratio (OR) of 1.483 (95 % Confidence interval [1.026–2.144]). Eventually, evaluating IMT by classifying ALS patients based on the ALS Health State Scale (ALSHSS) from early to late stage revealed a non-linear increase in the OR (1.372, 1.898, 2.172, and 3.403). ConclusionThe increased value of the carotid IMT independent of BMI in ALS could be assessed through ultrasonography as a convenient tool to evaluate the disease severity or possible systemic inflammation.

Construction and validation of a risk-prediction model for anastomotic leakage after radical gastrectomy: A cohort study in China

ObjectivesAnastomotic leakage (AL) stands out as a prevalent and severe complication following gastric cancer surgery. It frequently precipitates additional serious complications, significantly influencing the overall survival time of patients. This study aims to enhance the risk-assessment strategy for AL following gastrectomy for gastric cancer. MethodsThis study included a derivation cohort and validation cohort. The derivation cohort included patients who underwent radical gastrectomy at Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, from January 1, 2015 to December 31, 2020. An evidence-based predictor questionnaire was crafted through extensive literature review and panel discussions. Based on the questionnaire, inpatient data were collected to form a model-derivation cohort. This cohort underwent both univariate and multivariate analyses to identify factors associated with AL events, and a logistic regression model with stepwise regression was developed. A 5-fold cross-validation ensured model reliability. The validation cohort included patients from August 1, 2021 to December 31, 2021 at the same hospital. Using the same imputation method, we organized the validation-queue data. We then employed the risk-prediction model constructed in the earlier phase of the study to predict the risk of AL in the subjects included in the validation queue. We compared the predictions with the actual occurrence, and evaluated the external validation performance of the model using model-evaluation indicators such as the area under the receiver operating characteristic curve (AUROC), Brier score, and calibration curve. ResultsThe derivation cohort included 1377 patients, and the validation cohort included 131 patients. The independent predictors of AL after radical gastrectomy included age ≥65 y, preoperative albumin <35 g/L, resection extent, operative time ≥240 min, and intraoperative blood loss ≥90 mL. The predictive model exhibited a solid AUROC of 0.750 (95% CI: 0.694–0.806; p < 0.001) with a Brier score of 0.049. The 5-fold cross-validation confirmed these findings with a calibrated C-index of 0.749 and an average Brier score of 0.052. External validation showed an AUROC of 0.723 (95% CI: 0.564–0.882; p = 0.006) and a Brier score of 0.055, confirming reliability in different clinical settings. ConclusionsWe successfully developed a risk-prediction model for AL following radical gastrectomy. This tool will aid healthcare professionals in anticipating AL, potentially reducing unnecessary interventions.

Intermediate Repeat Expansion in the ATXN2 Gene as a Risk Factor in the ALS and FTD Spanish Population.

Intermediate CAG expansions in the gene ataxin-2 (ATXN2) are a known risk factor for ALS, but little is known about their role in FTD risk. Moreover, their contribution to the risk and phenotype of patients might vary in populations with different genetic backgrounds. The aim of this study was to assess the relationship of intermediate CAG expansions in ATXN2 with the risk and phenotype of ALS and FTD in the Spanish population. Repeat-primed PCR was performed in 620 ALS and 137 FTD patients in three referral centers in Spain to determine the exact number of CAG repeats. In our cohort, ≥27 CAG repeats in ATXN2 were associated with a higher risk of developing ALS (odds ratio [OR] = 2.666 [1.471-4.882]; p = 0.0013) but not FTD (odds ratio [OR] = 1.446 [0.558-3.574]; p = 0.44). Moreover, ALS patients with ≥27 CAG repeats in ATXN2 showed a shorter survival rate compared to those with <27 repeats (hazard ratio [HR] 1.74 [1.18, 2.56], p = 0.005), more frequent limb onset (odds ratio [OR] = 2.34 [1.093-4.936]; p = 0.028) and a family history of ALS (odds ratio [OR] = 2.538 [1.375-4.634]; p = 0.002). Intermediate CAG expansions of ≥27 repeats in ATXN2 are associated with ALS risk but not with FTD in the Spanish population. ALS patients carrying an intermediate expansion in ATXN2 show more frequent limb onset but a worse prognosis than those without expansions. In patients carrying C9orf72 expansions, the intermediate ATXN2 expansion might increase the penetrance and modify the phenotype.

Avocational exposure associations with ALS risk, survival, and phenotype: A Michigan-based case-control study

IntroductionEnvironmental exposures strongly influence ALS risk and identification is needed to reduce ALS burden. Participation in hobbies and exercise may alter ALS risk and phenotype, warranting an assessment to understand their contribution to the ALS exposome. MethodsParticipants with ALS and healthy controls were recruited from University of Michigan and self-completed a survey to ascertain hobbies, exercise, and avocational exposures. Exposure variables were associated with ALS risk, survival, onset segment, and onset age. ResultsALS (n = 400) and control (n = 287) participants self-reported avocational activities. Cases were slightly older (median age 63.0 vs. 61.1 years, p = 0.019) and had a lower educational attainment (p < 0.001) compared to controls; otherwise, demographics were well balanced. Risks associating with ALS after multiple comparison correction included golfing (odds ratio (OR) 3.48, padjusted = 0.004), recreational dancing (OR 2.00, padjusted = 0.040), performing gardening or yard work (OR 1.71, padjusted = 0.040) five years prior to ALS and personal (OR 1.76, padjusted = 0.047) or family (OR 2.21, padjusted = 0.040) participation in woodworking, and personal participation in hunting and shooting (OR 1.89, padjusted = 0.040). No exposures associated with ALS survival and onset. Those reporting swimming (3.86 years, padjusted = 0.016) and weightlifting (3.83 years, padjusted = 0.020) exercise 5 years prior to ALS onset had an earlier onset age. DiscussionThe identified exposures in this study may represent important modifiable ALS factors that influence ALS phenotype. Thus, exposures related to hobbies and exercise should be captured in studies examining the ALS exposome.

Recent advances in the genetics of familial and sporadic ALS.

ALS shows complex genetic inheritance patterns. In about 5% to 10% of cases, there is a family history of ALS or a related condition such as frontotemporal dementia in a first or second degree relative, and for about 80% of such people a pathogenic gene variant can be identified. Such variants are also seen in people with no family history because of factor influencing the expression of genes, such as age. Genetic susceptibility factors also contribute to risk, and the heritability of ALS is between 40% and 60%. The genetic variants influencing ALS risk include single base changes, repeat expansions, copy number variants, and others. Here we review what is known of the genetic landscape and architecture of ALS.

Association between allostatic load and breast cancer risk: a cohort study

BackgroundAllostatic load (AL) reflects the collective load of chronic stress during lifetime. Previous studies have shown that higher AL is associated with poor clinical outcomes among breast cancer patients. However, the relationship between AL and breast cancer risk is still unclear.MethodsTo fill the gap, we analyzed the association between AL and the development of breast cancer in 181,455 women identified from the UK Biobank.ResultsDuring the follow-up from 2006 to 2020, 5,701 women were diagnosed with incident breast cancer. Significantly higher AL was observed among incident breast cancer cases than all study participants (mean: 2.77 vs. 2.63, P < 0.01). Univariate Cox regression analysis indicated the risk of breast cancer was increased by 5% per one AL unit increase (hazard ratio (HR) = 1.05, 95% confidence interval (CI) 1.04, 1.07). In multivariate analyses, after adjusting demographics, family history of breast cancer, reproductive factors, socioeconomic status, lifestyle factors, and breast cancer polygenic risk score (PRS), the significant association remained (HR = 1.05, 95%CI 1.03, 1.07). The significant relationship was further confirmed in the categorical analysis. Compared with women in the low AL group (AL: 0 ~ 2), those in the high AL group (AL: 3 ~ 11) had a 1.17-fold increased risk of breast cancer (HR = 1.17, 95%CI 1.11, 1.24). Finally, in the stratified analysis, joint effects on the risk of breast cancer were observed between the AL and selected known breast cancer risk factors, including age, family history of breast cancer, PRS, income, physical activity, and alcohol consumption.ConclusionIn summary, those findings have demonstrated that higher AL was associated with an increased breast cancer risk in women. This association is likely independent of known breast cancer risk factors. Thus, the AL could be a valuable biomarker to help breast cancer risk prediction and stratification.

Mutation and clinical analysis of the CLCC1 gene in amyotrophic lateral sclerosis patients from Central South China.

Recently, chloride channel CLIC-like 1 (CLCC1) was reported to be a novel ALS-related gene. We aimed to screen CLCC1 variants in our ALS cohort and further explore the genotype-phenotype correlation of CLCC1-related ALS. We screened rare damaging variants in CLCC1 from our cohorts of 1005 ALS patients and 1224 healthy controls with whole-exome sequencing in Central South China. Fisher's exact test was conducted for association analysis at the entire gene level and single variant level. In total, four heterozygous missense variants in CLCC1 were identified from four unrelated sporadic ALS patients and predicted to be putative pathogenic by in silico tools and protein model prediction, accounting for 0.40% of all patients (4/1005). The four variants were c.A275C (p.Q92P), c.G1139A (p.R380K), c.C1244T (p.T415M), and c.G1328A (p.R443Q), respectively, which had not been reported in ALS patients previously. Three of four variants were located in exon 10. Patients harboring CLCC1 variants seemed to share a group of similar clinical features, including earlier age at onset, rapid progression, spinal onset, and vulnerable cognitive status. Statistically, we did not find CLCC1 to be associated with the risk of ALS at the entire gene level or single variant level. Our findings further expanded the genetic and clinical spectrum of CLCC1-related ALS and provided more genetic evidence for anion channel involvement in the pathogenesis of ALS, but further investigations are needed to verify our findings.

Anastomotic leakage and functional outcomes following total mesorectal excision with delayed and immediate colo-anal anastomosis for rectal cancer: Two single-arm phase II trials

BackgroundAnastomotic leakage (AL) remains a major cause of morbidity following total mesorectal excision (TME). A diverting ileostomy reduces the risk of AL but impairs quality of life (QoL). Delayed colo-anal anastomosis (DCAA) may be an alternative to immediate colo-anal anastomosis (ICAA) without creation of a diverting ileostomy. Study designPatients with T3 or N+ rectal tumours were treated with neoadjuvant chemoradiation and TME. To evaluate DCAA or ICAA with diverting ileostomy, a two multicenter single-arm phase II trials was designed. The primary endpoint was the rate of AL requiring a diverting ileostomy up to 30 days postoperatively. Secondary endpoints were 30-day postoperative complications, 1- and 2-year disease-free survival; QoL at baseline, 6 months and anorectal function measured by the low anterior resection syndrome questionnaire and Wexner score at baseline, 6 months and a late assessment at median 8 years following surgery. ResultsAL requiring diverting ileostomy occurred in one patient (2.1%; 95% confidence interval (CI) [0; 11.1]) in the DCAA group and in five patients (8.6%; 95%CI [3.2; 21.0]) in the ICAA group. Thirty-day postoperative complications occurred in 13 patients (27.1%) in the DCAA group and in 10 patients (19.2%) in the ICAA group. Short and long-term functional outcomes showed similar patterns. ConclusionThese two single-arm phase II trials showed that DCAA has low rates of AL requiring a diverting ileostomy and acceptable long-term functional results. DCAA seems a good choice to restore bowel continuity.

LAENALS: epidemiological and clinical features of amyotrophic lateral sclerosis in Latin America

Objective The Latin American Epidemiologic study of ALS (LAENALS) aims to gather data on ALS epidemiology, phenotype, and risk factors in Cuba, Chile, and Uruguay, to understand the impact of genetic and environmental factors on ALS. Methods A harmonized data collection protocol was generated, and a Latin-American Spanish language Register was constructed. Patient data were collected in Uruguay in 2018, in Chile from 2017 to 2019, and in Cuba between 2017 and 2018. Statistical analysis was performed using SPSS 25.0.0 software. Crude cumulative incidence, standardized incidence, and prevalence were calculated in the population aged 15 years and older. Results During 2017-2019, 90 people with ALS from Uruguay (55.6% men), 219 from Chile (54.6% men), and 49 from Cuba (55.1% men) were included. The cumulative crude incidence in 2018 was 1.73/100,000 persons in Uruguay, 1.08 in Chile and 0.195 in Cuba. Crude prevalence in 2018 was 2.19 per 100,000 persons in Uruguay, 1.39 in Chile and 0.55 in Cuba. Mean age at onset was 61.8 ± 11.96 SD years in Uruguay, 61.9 ± 10.4 SD years in Chile, and 60.21 ± 12.45 SD years in Cuba (p = 0.75). Median survival from onset was 32.43 months (21.93 − 42.36) in Uruguay, 24 months (13.5 − 33.5) in Chile, and 29 months (15 − 42.5) in Cuba (p = 0.006). Conclusions These preliminary data from LAENALS confirm the lower incidence and prevalence of ALS in counties with admixed populations. The LAENALS database is now open to other Latin American countries for harmonized prospective data collection.

Assessment of risk of ALS conferred by the GGGGCC hexanucleotide repeat expansion in C9orf72 among first-degree relatives of patients with ALS carrying the repeat expansion

Objectives We aimed to estimate the age-related risk of ALS in first-degree relatives of patients with ALS carrying the C9orf72 repeat expansion. Methods We included all patients with ALS carrying a C9orf72 repeat expansion in The Netherlands. Using structured questionnaires, we determined the number of first-degree relatives, their age at death due to ALS or another cause, or age at time of questionnaire. The cumulative incidence of ALS among first-degree relatives was estimated, while accounting for death from other causes. Variability in ALS risk between families was evaluated using a random effects hazards model. We used a second, distinct approach to estimate the risk of ALS and FTD in the general population, using previously published data. Results In total, 214 of the 2,486 (9.2%) patients with ALS carried the C9orf72 repeat expansion. The mean risk of ALS at age 80 for first-degree relatives carrying the repeat expansion was 24.1%, but ranged between individual families from 16.0 to 60.6%. Using the second approach, we found the risk of ALS and FTD combined was 28.7% (95% CI 17.8%–54.3%) for carriers in the general population. Conclusions On average, our estimated risk of ALS in the C9orf72 repeat expansion was lower compared to historical estimates. We showed, however, that the risk of ALS likely varies between families and one overall penetrance estimate may not be sufficient to describe ALS risk. This warrants a tailor-made, patient-specific approach in testing. Further studies are needed to assess the risk of FTD in the C9orf72 repeat expansion.

Cortical structure and the risk of amyotrophic lateral sclerosis: A bidirectional Mendelian randomization study

BackgroundCurrent observational studies indicate progressive brain atrophy is closely associated with the clinical feature of amyotrophic lateral sclerosis. However, it is unclear whether the changes in cortical structure are the cause or result of ALS. Our study aimed to investigate the causal relationship between cortical structure and ALS risk using a bidirectional two-sample MR study. MethodsWe collected publicly available genome-wide association studies' summary statistics for cortical structure from UK Biobank and ENIGMA consortium (n = 33,992) and ALS from the Project MinE (n = 138,086). We used the inverse variance weighted method (IVW) as primary analysis in order to evaluate the causal effects. In addition, the weighted median and MR Egger methods were performed to ensure the robustness and reliability of the IVW results. ResultsWe found the decreased surface of the paracentral lobule and thickness of the frontal pole and middle temporal lobe were suggestively associated with an increased risk of ALS as well as the increased surface of medial orbitofrontal and middle temporal lobe. In another aspect, the causalities between the susceptibility to ALS and the volume of the transverse temporal gyrus and superior temporal gyrus were negative. Besides, the susceptibility to ALS might also contribute to an increased thickness of the postcentral gyrus and superior parietal gyrus. ConclusionIn this two-sample MR analysis, we observed that multiple cortical brain regions are associated with a higher ALS risk. Further research into the underlying mechanisms is required to back up our findings.

Risk assessment of rectal anastomotic leakage (RAREAL) after DIXON in non-emergency patients with rectal cancer

BackgroundThe routine establishment of a diverting stoma (DS) remains controversial in every patient undergoing Dixon operation. We aimed to establish a model for the risk assessment of rectal anastomotic leak (RAREAL) after Dixon in non-emergency patients with rectal cancer, using routinely available variables, by which surgeons could individualize their approach to DS.Methods323 patients who underwent Dixon operation for rectal cancer from January 2015 to December 2018 were taken as the model group for retrospective study. Univariable and multivariable logistic regression analysis was used to determine the independent risk factors associated with anastomotic leakage. We constructed the RAREAL model. 150 patients who underwent Dixon operation due to rectal cancer from January 2019 to December 2020 were collected according to the uniform criteria as a validation group to validate the RAREAL model.ResultsIn the model group, multivariable analysis identified the following variables as independent risk factors for AL: HbA1c (odds ratio (OR) = 4.107; P = 0.044), Left colic artery (LCA) non preservation (OR = 4.360; P = 0.026), Tumor distance from the anal margin (TD) (OR = 6.373; P = 0.002). In the model group, the area under the curve (AUC) of the receiver operating characteristic (ROC) for evaluating AL with RAREAL was 0.733, and when RAREAL score = 2.5, its sensitivity, specificity and Youden index were 0.385, 0.973, 0.358, respectively. The AUC was 0.722 in the validation group and its sensitivity and specificity were 0.333 and 0.985, respectively, when RAREAL score = 2.5.ConclusionThe RAREAL score can be used to assess the risk of AL after Dixon operation for rectal cancer, and prophylactic DS should be proactively done when the score is greater than 2.5.

A distinct circular DNA profile intersects with proteome changes in the genotoxic stress-related hSOD1G93A model of ALS

BackgroundNumerous genes, including SOD1, mutated in familial and sporadic amyotrophic lateral sclerosis (f/sALS) share a role in DNA damage and repair, emphasizing genome disintegration in ALS. One possible outcome of chromosomal instability and repair processes is extrachromosomal circular DNA (eccDNA) formation. Therefore, eccDNA might accumulate in f/sALS with yet unknown function.MethodsWe combined rolling circle amplification with linear DNA digestion to purify eccDNA from the cervical spinal cord of 9 co-isogenic symptomatic hSOD1G93A mutants and 10 controls, followed by deep short-read sequencing. We mapped the eccDNAs and performed differential analysis based on the split read signal of the eccDNAs, referred as DifCir, between the ALS and control specimens, to find differentially produced per gene circles (DPpGC) in the two groups. Compared were eccDNA abundances, length distributions and genic profiles. We further assessed proteome alterations in ALS by mass spectrometry, and matched the DPpGCs with differentially expressed proteins (DEPs) in ALS. Additionally, we aligned the ALS-specific DPpGCs to ALS risk gene databases.ResultsWe found a six-fold enrichment in the number of unique eccDNAs in the genotoxic ALS-model relative to controls. We uncovered a distinct genic circulome profile characterized by 225 up-DPpGCs, i.e., genes that produced more eccDNAs from distinct gene sequences in ALS than under control conditions. The inter-sample recurrence rate was at least 89% for the top 6 up-DPpGCs. ALS proteome analyses revealed 42 corresponding DEPs, of which 19 underlying genes were itemized for an ALS risk in GWAS databases. The up-DPpGCs and their DEP tandems mainly impart neuron-specific functions, and gene set enrichment analyses indicated an overrepresentation of the adenylate cyclase modulating G protein pathway.ConclusionsWe prove, for the first time, a significant enrichment of eccDNA in the ALS-affected spinal cord. Our triple circulome, proteome and genome approach provide indication for a potential importance of certain eccDNAs in ALS neurodegeneration and a yet unconsidered role as ALS biomarkers. The related functional pathways might open up new targets for therapeutic intervention.Graphical

The influence of arable crops on ALS risk and age at onset: a population-based study (S19.006)

<h3>Objective:</h3> We investigated the effect of living near to specific agricultural crops on the ALS risk, age at onset and other phenotypical variables. <h3>Background:</h3> Several environmental risk factors, such as agricultural workers, have been related to ALS risk, but with inconsistent results. Regarding phenotypic heterogeneity, a recent study failed to identify possible environmental factors underlying ALS clinical presentation. <h3>Design/Methods:</h3> All ALS patients (diagnosis 2007–2014) belong to the Piemonte and Valle d’Aosta Register (PARALS). Using Regional Environmental Protection Agency (ARPA) data, we established the geographical distribution of agricultural areas in the same period. We calculated the area covered by each culture and patients smoothed incidence and we compared them using linear regression. A proximity score for each environmental factor was calculated using the area of the environmental component enclosed by a circle centered on the residence address, (variable radii 100–2000 meters). <h3>Results:</h3> The regression model for arable crops confirmed a linear increase in ALS incidence in the municipalities with a larger area covered by arable crops. Median incidence increased from 0.75 (IQR 0.00–1.26) cases/100.000/year in municipalities with no area covered by arable crops to 1.81 (IQR 0.75–4.11) cases/100.000/year where arable crops covered more than 60% of total municipality area. The proximity score analysis confirmed that arable crops proximity (considering a 500, 1000, 1500 meters radii) significantly reduced the age at onset by about 2 years. Linear regression for proximity score and age at onset, significantly confirm this trend (R= −0.51675, p=0.0245). We confirmed the same trend by subgrouping patients according to sex and site of onset. <h3>Conclusions:</h3> We confirmed an higher ALS patients incidence for the municipality with high percentage of arable land. Arable land proximity scores resulted to be the related to a significantly reduced median onset age, confirming the presence of possible shared environmental factors that could anticipate disease onset in the exposed population <b>Disclosure:</b> Dr. Calvo has nothing to disclose. Mr. Callegaro has nothing to disclose. Dr. Vasta has nothing to disclose. Mr. Grassano has nothing to disclose. Antonio Canosa has nothing to disclose. Sara Cabras has nothing to disclose. Dr. Di Pede has nothing to disclose. Dr. Matteoni has nothing to disclose. Fabiola De Marchi has nothing to disclose. Letizia Mazzini has nothing to disclose. Cristina Moglia has nothing to disclose. Dr. Chio has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Cytokinetics. Dr. Chio has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Mitsubishi. Dr. Chio has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Dr. Manera has nothing to disclose.

Association of blood lipids with onset and prognosis of amyotrophic lateral sclerosis: results from the ALS Swabia registry

BackgroundTo date, the role of blood lipid levels and their association with the onset and prognosis of ALS is controversial. We explored these associations in a large, population-based case–control study.MethodsBetween October 2010 and June 2014, 336 ALS patients (mean age 65.7 ± 10.7; 57.7% male) and 487 sex- and age-matched controls from the same geographic region were recruited within the ALS registry in Southwest Germany. Triglycerides and cholesterol (high-density lipoprotein (HDL), low-density lipoprotein (LDL), total) were measured. The ALS cohort was followed up for vital status. Conditional logistic regression models were applied to calculate odds ratio (OR) for risk of ALS associated with serum lipid concentrations. In ALS patients only, survival models were used to appraise the prognostic value.ResultsHigh concentration of total cholesterol (OR 1.60, 95% confidence interval (CI) 1.03–2.49, top vs. bottom quartile), but not HDL, LDL, LDL–HDL ratio, or triglycerides, was positively associated with the risk of ALS. During the median follow-up time of 88.9 months, 291 deaths occurred among 336 ALS patients. In the adjusted survival analysis, higher HDL (HR 1.72, 95% CI 1.19–2.50) and LDL cholesterol levels (HR 1.58, 95% CI 1.11–2.26) were associated with higher mortality in ALS patients. In contrast, higher triglyceride levels were associated with lower mortality (HR 0.68, 95% CI 0.48–0.96).ConclusionThe results highlight the importance to distinguish cholesterol from triglycerides when considering the prognostic role of lipid metabolism in ALS. It further strengthens the rationale for a triglyceride-rich diet, while the negative impact of cholesterol must be further explored.

The HFE p.H63D (p.His63Asp) Polymorphism Is a Modifier of ALS Outcome in Italian and French Patients with SOD1 Mutations

Background: Data from published studies about the effect of HFE polymorphisms on ALS risk, phenotype, and survival are still inconclusive. We aimed at evaluating whether the p.H63D polymorphism is a modifier of phenotype and survival in SOD1-mutated patients. Methods: We included 183 SOD1-mutated ALS patients. Mutations were classified as severe or mild according to the median survival of the study population. Patients were screened for the HFE p.H63D polymorphism. Survival was calculated using the Kaplan-Meier modeling, and differences were measured by the log-rank test. Multivariable analysis was performed with the Cox proportional hazards model (stepwise backward). Results: SOD1 severe mutation carriers show more frequent familial history for ALS and shorter survival compared to mild mutation carriers. Carriers and non-carriers of the p.H63D polymorphism did not differ in terms of sex ratio, frequency of positive familial history, age at onset, and bulbar/spinal ratio. In univariate and in Cox multivariable analysis using sex, age at onset, site of onset, family history, country of origin, and mutation severity as covariates, p.H63D carriers had a longer survival (p = 0.034 and p = 0.004). Conclusions: We found that SOD1-mutated ALS patients carrying the p.H63D HFE polymorphism have a longer survival compared to non-carriers, independently of sex, age and site of onset, family history, nation of origin, and severity of mutations, suggesting a possible role as disease progression modifier for the p.H63D HFE polymorphism in SOD1-ALS.