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Amyotrophic lateral sclerosis is a heterogeneous, fatal neurodegenerative disease, characterized by motor neuron loss and in 50% of cases also by cognitive and/or behavioral changes. Mendelian forms of ALS comprise approximately 10-15% of cases. The majority is however considered sporadic, but also with a high contribution of genetic risk factors. To explore the contribution of somatic mutations and/or epigenetic changes to disease risk, we performed whole genome sequencing and methylation analyses using samples from multiple tissues on a cohort of 26 monozygotic twins discordant for ALS, followed by in-depth validation and replication experiments. The results of these analyses implicate several mechanisms in ALS pathophysiology, which include a role for de novo mutations, defects in DNA damage repair and accelerated aging., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: C9orf72 mutation carriers with different neurological phenotypes show cortical and subcortical atrophy in multiple different brain regions, even in pre-symptomatic phases. Despite there is a substantial amount of knowledge, small sample sizes, clinical heterogeneity, as well as different choices of image analysis may hide anatomical abnormalities that are unique to amyotrophic lateral sclerosis (ALS) patients with this genotype or that are indicative of the C9orf72-specific trait overlain in fronto-temporal dementia patients., Methods: Brain structural and resting state functional magnetic imaging was obtained in 24 C9orf72 positive (ALSC9+) ALS patients paired for burden disease with 24 C9orf72 negative (ALSC9-) ALS patients. A comprehensive structural evaluation of cortical thickness and subcortical volumes between ALSC9+ and ALSC9- patients was performed while a region of interest (ROI)-ROI analysis of functional connectivity was implemented to assess functional alterations among abnormal cortical and subcortical regions. Results were corrected for multiple comparisons., Results: Compared to ALSC9- patients, ALSC9+ patients exhibited extensive disease-specific patterns of thalamo-cortico-striatal atrophy, supported by functional alterations of the identified abnormal regions. Cortical thinning was most pronounced in posterior areas and extended to frontal regions. Bilateral atrophy of the mediodorsal and pulvinar nuclei was observed, emphasizing a focal rather than global thalamus atrophy. Volume loss in a large portion of bilateral caudate and left putamen was reported. The marked reduction of functional connectivity observed between the left posterior thalamus and almost all the atrophic cortical regions support the central role of the thalamus in the pathogenic mechanism of C9orf72-mediated disease., Conclusions: These findings constitute a coherent and robust picture of ALS patients with C9orf72-mediated disease, unveiling a specific structural and functional characterization of thalamo-cortico-striatal circuit alteration. Our study introduces new evidence in the characterization of the pathogenic mechanisms of C9orf72 mutation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

We report a case of childhood-onset ALS with a FUS gene mutation presenting cognitive impairment and a rapid clinical progression. The patient, an 11-year-old girl, presented with right distal upper limb weakness and mild intellectual disability at the Griffith Mental Development Scales. The disease rapidly worsened and the patient became tetraplegic and bed-ridden 2 years after symptom onset. A c.1509_1510delAG mutation in exon 14 of the FUS gene was detected, resulting in a predicted truncated protein, p.G504Wfs*12, lacking the nuclear localization signal. The levels of FUS mRNA in the proband were not significantly different compared to controls. Western immunoblot analysis showed that one antibody (500-526) detected in the proband ~50% of the amount of FUS protein compared to controls, while 3 other antibodies (2-27, 400-450 and FUS C-terminal), which recognize both wild type and the mutated FUS, detected 60% to 75% of the amount of the protein. These findings indicate that p.G504Wfs*12 FUS is more prone to undergo post-translational modification respect to wild type FUS., (Copyright © 2021. Published by Elsevier Inc.)

We tested the Cognitive Reserve (CR) hypothesis in Amyotrophic Lateral Sclerosis (ALS), enrolling 111 patients, using education as CR proxy, 18 F-FDG-PET to assess brain damage, and ECAS to measure cognition. Education was regressed out against brain metabolism, including age, sex, spinal/bulbar onset, ALSFRS-R, and ECAS as covariates. Clusters showing a significant correlation were used as seed regions in an interregional correlation analysis (IRCA) in the ALS group and in 40 controls. In the ALS group, we found a negative correlation between brain metabolism and education in the right anterior cingulate and bilateral medial frontal gyrus. In the IRCA in the ALS group, the medial frontal cluster metabolism positively correlated with that of frontotemporal regions (right > left), bilateral caudate nuclei, and right insula, and negatively correlated with that of corticospinal tracts, cerebellum, and pons. In controls, the IRCA showed significant positive correlations in the same regions but less extended. Our results agree with the CR hypothesis. The negative correlation between the medial frontal cluster and the cerebellum found only in ALS patients might reflect cerebellar compensation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To evaluate the metabolic correlates of lifetime sport practice in ALS through brain 18 F-FDG-PET., Methods: 131 patients completed a questionnaire about lifetime exposures, including physical activity related to sports, hobbies and occupations, and underwent brain 18 F-FDG-PET. Exposure to sports was expressed as MET (Metabolic Equivalent of Task). We considered only regular practice (at least 2 h/week, for at least three months). We compared brain metabolism between two groups: subjects who did not report regular sport practice during life (N-group) and patients who did (Y-group). The resulting significant clusters were used in each group as seed regions in an interregional correlation analysis (IRCA) to evaluate the impact of lifetime sport practice on brain networks typically involved by the neurodegenerative process of ALS. Each group was compared to healthy controls (HC, n = 40)., Results: We found a significant, relative cerebellar hypermetabolism in the N-group compared to the Y-group. The metabolism of such cerebellar cluster resulted correlated to more significant and widespread metabolic changes in areas known to be affected by ALS (i.e. frontotemporal regions and corticospinal tracts) in the N-group as compared to the Y-group, despite the same level of disability as expressed by the ALS FRS-R. Such findings resulted independent of age, sex, site of onset (bulbar/spinal), presence/absence of C9ORF72 expansion, cognitive status and physical activity related to hobbies and occupations. When compared to HC, the N-group showed more widespread metabolic changes than the Y-group in cortical regions known to be relatively hypometabolic in ALS patients as compared to HC., Conclusions: We hypothesize that patients of the N-group might cope better with the neurodegenerative process, since they show more widespread metabolic changes as compared to the Y-group, despite the same level of disability. Nevertheless, further studies are necessary to corroborate this hypothesis., (Copyright © 2020. Published by Elsevier Inc.)

Objective: The motor unit size index (MUSIX) is incorporated into the motor unit number index (MUNIX). Our objective was to assess the intra-/inter-rater reliability of MUSIX in healthy volunteers across single subject "round robin" and multi-centre settings., Methods: Data were obtained from (i) a round-robin assessment in which 12 raters (6 with prior experience and 6 without) assessed six muscles (abductor pollicis brevis, abductor digiti minimi, biceps brachii, tibialis anterior, extensor digitorum brevis and abductor hallucis) and (ii) a multi-centre study with 6 centres studying the same muscles in 66 healthy volunteers. Intra/inter-rater data were provided by 5 centres, 1 centre provided only intra-rater data. Intra/inter-rater variability was assessed using the coefficient of variation (COV), Bland-Altman plots, bias and 95% limits of agreement., Results: In the round-robin assessment intra-rater COVs for MUSIX ranged from 7.8% to 28.4%. Inter-rater variability was between 7.8% and 16.2%. Prior experience did not impact on MUSIX values. In the multi-centre study MUSIX was more consistent than the MUNIX. Abductor hallucis was the least reliable muscle., Conclusions: The MUSIX is a reliable neurophysiological biomarker of reinnervation., Significance: MUSIX could provide insights into the pathophysiology of a range of neuromuscular disorders, providing a quantitative biomarker of reinnervation., (Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

We report an apparently sporadic amyotrophic lateral sclerosis patient carrying a heterozygous novel frameshift SOD1 mutation (p.Ser108LeufsTer15), predicted to cause a premature protein truncation. RT-PCR analysis of SOD1 mRNA and SDS-PAGE/Western blot analysis of PBMC demonstrated that mRNA from the mutant allele is expressed at levels similar to those of the wild-type allele, but the truncated protein is undetectable also in the insoluble fraction and after proteasome inhibition. Accordingly, the dismutation activity in erythrocytes is halved. Thus, the pathogenic mechanism associated with this mutation might be based on an insufficient activity of SOD1 that would make motor neurons more vulnerable to oxidative injury. However, it cannot be excluded that p.Ser108LeufsTer15 SOD1 is present in the nervous tissue and, being less charged and hence having less repulsive forces than the wild-type protein, may trigger toxic mechanisms as a consequence of its propensity to aggregate., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Recently, mutations in the TANK-binding kinase 1 (TBK1) gene were identified as a cause for amyotrophic lateral sclerosis (ALS) with or without comorbid frontotemporal dementia. We have assessed the frequency and clinical characteristics of TBK1 mutations in a cohort of ALS patients of Sardinian ancestry. Whole-exome sequencing was performed on Hiseq2000 platform (Illumina). Genome analysis Toolkit was used to align and to code variants according to Human Genome (UCSC hg19). Mutation was confirmed with Sanger sequence. In our screening of 186 Sardinian ALS cases, we found 3 (1.6%) patients carrying 3 distinct novel genetic variants: a nonsynonymous SNV c.1150C>T leading to a p.Arg384Thr change in exon 9; a nonsynonymous SNV c.1331G>A causes a p.Arg444Gln change in exon 11; and a frameshift deletion c.2070delG (p.Met690fs) at the exon 20 of the gene leading to a stop at 693 codon. The latter patients also carried missense mutation c.98C>T of the SQSTM1 gene causing a substitution of an arginine with a valine at the position 33 (p.Arg33Val). All variants were found to be deleterious according to in silico predictions. All cases were apparently sporadic and one of them showed frontotemporal dementia associated to ALS. These mutations were not found in 2 cohorts of 6780 ethnic-matched controls. We have found that TBK1 mutations account for 1.6% of Sardinian ALS cases. Our data support the notion that TBK1 is a novel ALS gene, providing important evidence complementary to the first descriptions., (Copyright © 2016 Elsevier Inc. All rights reserved.)

There are indications that both familial amyotrophic lateral sclerosis (ALS) and sporadic ALS phenotype and prognosis are partly regulated by genetic and environmental factors, supporting the theory that ALS is a multifactorial disease. The aim of this article was to assess the role of ATXN2 intermediate length repeats in a large series of Italian and Sardinian ALS patients and controls carrying a pathogenetic C9ORF72 GGGGCC hexanucleotide repeat. A total of 1972 ALS cases were identified through the database of the Italian ALS Genetic consortium, a collaborative effort including 18 ALS centers throughout Italy. The study population included: (1) 276 Italian and 57 Sardinian ALS cases who carried the C9ORF72 expansion; (2) 1340 Italian and 299 Sardinian ALS cases not carrying the C9ORF72 expansion. A total of healthy 1043 controls were also assessed. Most Italian and Sardinian cases and controls were homozygous for 22/22 or 23/23 repeats or heterozygous for 22/23 repeats of the ATXN2 gene. ATXN2 intermediate length repeats alleles (≥28) were detected in 3 (0.6%) Italian ALS cases carrying the C9ORF72 expansion, in none of the Sardinian ALS cases carrying the expansion, in 60 (4.3%) Italian cases not carrying the expansion, and in 6 (2.0%) Sardinian ALS cases without C9ORF72 expansion. Intermediate length repeat alleles were found in 12 (1.5%) Italian controls and 1 (0.84%) Sardinian controls. Therefore, ALS patients with C9ORF72 expansion showed a lower frequency of ATXN2 polyQ intermediate length repeats than both controls (Italian cases, p = 0.137; Sardinian cases, p = 0.0001) and ALS patients without C9ORF72 expansion (Italian cases, p = 0.005; Sardinian cases, p = 0.178). In our large study on Italian and Sardinian ALS patients with C9ORF72 GGGGCC hexanucleotide repeat expansion, compared to age-, gender- and ethnic-matched controls, ATXN2 polyQ intermediate length does not represent a modifier of ALS risk, differently from non-C9ORF72 mutated patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

It has been recently reported that the p.His63Asp polymorphism of the HFE gene accelerates disease progression both in the SOD1 transgenic mouse and in amyotrophic lateral sclerosis (ALS) patients. We have evaluated the effect of HFE p.His63Asp polymorphism on the phenotype in 1351 Italian ALS patients (232 of Sardinian ancestry). Patients were genotyped for the HFE p.His63Asp polymorphism (CC, GC, and GG). All patients were also assessed for C9ORF72, TARDBP, SOD1, and FUS mutations. Of the 1351 ALS patients, 363 (29.2%) were heterozygous (GC) for the p.His63Asp polymorphism and 30 (2.2%) were homozygous for the minor allele (GG). Patients with CC, GC, and GG polymorphisms did not significantly differ by age at onset, site of onset of symptoms, and survival; however, in SOD1 patients with CG or GG polymorphism had a significantly longer survival than those with a CC polymorphism. Differently from what observed in the mouse model of ALS, the HFE p.His63Asp polymorphism has no effect on ALS phenotype in this large series of Italian ALS patients., Competing Interests: statement The authors have no actual or potential conflicts of interest., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Intermediate-length CAG expansions (encoding 27-33 glutamines, polyQ) of the Ataxin2 (ATXN2) gene represent a risk factor for amyotrophic lateral sclerosis (ALS). Recently, it has been proposed that ≥31 CAG expansions may influence ALS phenotype. We assessed whether ATXN2 intermediate-length polyQ expansions influence ALS phenotype in a series of 375 patients of Sardinian ancestry. Controls were 247 neurologically healthy subjects, resident in the study area, age- and gender-matched to cases. The frequency of ≥31 polyQ ATNX2 repeats was significantly more common in ALS cases (4 patients vs. no control, p = 0.0001). All patients with ≥31 polyQ repeats had a spinal onset versus 73.3% of patients with <31 polyQ repeats. Patients with an increased number of polyQ repeats have a shorter survival than those with <31 repeats (1.2 vs. 4.2 years, p = 0.035). In this large series of ALS patients of Sardinian ancestry, we have found that ≥31 polyQ repeats of the ATXN2 gene influenced patients' phenotype, being associated to a spinal onset and a significantly shorter survival., Competing Interests: statement All other authors report no conflicts of interest., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Mutations in CHCHD10 have recently been described as a cause of frontotemporal dementia (FTD) comorbid with amyotrophic lateral sclerosis (ALS). The aim of this study was to assess the frequency and clinical characteristics of CHCHD10 mutations in Italian patients diagnosed with familial (n = 64) and apparently sporadic ALS (n = 224). Three apparently sporadic patients were found to carry c.100C>T (p.Pro34Ser) heterozygous variant in the exon 2 of CHCHD10. This mutation had been previously described in 2 unrelated French patients with FTD-ALS. However, our patients had a typical ALS, without evidence of FTD, cerebellar or extrapyramidal signs, or sensorineural deficits. We confirm that CHCHD10 mutations account for ∼ 1% of Italian ALS patients and are a cause of disease in subjects without dementia or other atypical clinical signs., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Conserved populations, such as Sardinians, displaying elevated rates of familial or sporadic amyotrophic lateral sclerosis (ALS) provide unique information on the genetics of the disease. Our aim was to describe the genetic profile of a consecutive series of ALS patients of Sardinian ancestry. All ALS patients of Sardinian ancestry, identified between 2008 and 2013 through the Italian ALS Genetic Consortium, were eligible to be included in the study. Patients and controls underwent the analysis of TARDBP, C9ORF72, SOD1, and FUS genes. Genetic mutations were identified in 155 out of 375 Sardinian ALS cases (41.3%), more commonly the p.A382T and p.G295S mutations of TARDBP and the GGGGCC hexanucleotide repeat expansion of C9ORF72. One patient had both p.G295S and p.A382T mutations of TARDBP and 8 carried both the heterozygous p.A382T mutation of TARDBP and a repeat expansion of C9ORF72. Patients carrying the p.A382T and the p.G295S mutations of TARDBP and the C9ORF72 repeat expansion shared distinct haplotypes across these loci. Patients with cooccurrence of C9ORF72 and TARDBP p.A382T missense mutation had a significantly lower age at onset and shorter survival. More than 40% of all cases on the island of Sardinia carry a mutation of an ALS-related gene, representing the highest percentage of ALS cases genetically explained outside of Scandinavia. Clinical phenotypes associated with different genetic mutations show some distinctive characteristics, but the heterogeneity between and among families carrying the same mutations implies that ALS manifestation is influenced by other genetic and nongenetic factors., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Mutations in C9ORF72, SOD1, TARDBP, and FUS genes account for approximately two-third of familial cases and 5% of sporadic amyotrophic lateral sclerosis (ALS) cases. We present the first case of an ALS patient carrying a de novo nonsense mutation in exon 14 of the FUS gene (c.1483c>t; p.R495X) with an apparently familial ALS. This mutation causes a phenotype characterized by a young age at onset, a rapid course (<24 months), and a bulbar onset with early respiratory involvement with a predominant lower motor neuron disease. De novo mutations could account for a sizable number of apparently sporadic ALS patients carrying mutations of ALS-related genes., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The common variant rs12608932, located within an intron of UNC13A gene on chromosome 19p13.3, has been suggested to influence susceptibility to amyotrophic lateral sclerosis (ALS), as well as survival, in patients of north European descent. To examine this possibility further, we evaluated the association of rs12608932 with susceptibility and survival in a population-based cohort of 500 Italian ALS patients and 1457 Italian control samples. Although rs12608932 was not associated with ALS susceptibility in our series (p = 0.124), it was significantly associated with survival under the recessive model (median survival for AA/AC genotypes = 3.5 years [interquartile range, 2.2-6.4]; CC = 2.5 years [interquartile range, 1.6-4.2]; p = 0.017). Furthermore, rs12608932 genotype remained an independent prognostic factor in Cox multivariable analysis adjusting for other factors known to influence survival (p = 0.023). Overall, minor allele carrier status of rs12608932 was strongly associated with an approximate 1-year reduction of survival in ALS patients, making it a significant determinant of phenotype variation. The identification of UNC13A as a modifier of prognosis among sporadic ALS patients potentially provides a new therapeutic target aimed at slowing disease progression., (Copyright © 2013 Elsevier Inc. All rights reserved.)

It has been recently reported that a large proportion of patients with familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are associated with a hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72. We have assessed 1757 Italian sporadic ALS cases, 133 from Sardinia, 101 from Sicily, and 1523 from mainland Italy. Sixty (3.7%) of 1624 mainland Italians and Sicilians and 9 (6.8%) of the 133 Sardinian sporadic ALS cases carried the pathogenic repeat expansion. None of the 619 regionally matched control samples (1238 chromosomes) carried the expansion. Twenty-five cases (36.2%) had behavioral FTD in addition to ALS. FTD or unspecified dementia was also detected in 19 pedigrees (27.5%) in first-degree relatives of ALS patients. Cases carrying the C9ORF72 hexanucleotide expansion survived 1 year less than cases who did not carry this mutation. In conclusion, we found that C9ORF72 hexanucleotide repeat expansions represents a sizeable proportion of apparent sporadic ALS in the Italian and Sardinian population, representing by far the most common mutation in Italy and the second most common in Sardinia., (Copyright © 2012 Elsevier Inc. All rights reserved.)

We have recently published data showing that a founder mutation of the TARDBP gene (p.A382T) accounts for approximately one third of amyotrophic lateral sclerosis (ALS) cases on the Mediterranean island of Sardinia (Chiò et al., 2011). In that report, we identified a 53-year-old man carrying a homozygous A382T missense mutation of the TARDBP gene with a complex neurological syndrome including amyotrophic lateral sclerosis, parkinsonian features, motor and vocal tics, and frontotemporal dementia (FTD). Due to the uniqueness of this case, here we provide a detailed clinical description, as well as neurophysiological, neuropsychological, and neuroimaging data for that case and his extended family., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Mutations in the Cu/Zn superoxide dismutase (SOD1), transactive response (TAR)-DNA binding protein (TARDBP) and fused in sarcoma (FUS) genes account for approximately 1 third of familial amyotrophic lateral sclerosis (ALS) cases. Mutations in these genes have been found in 1% to 2% of apparently sporadic cases. We present the first case of an ALS patient carrying a de novo missense mutation of the FUS gene (c.1561C>T, p.R521C). This report highlights the importance of screening ALS patients, both familial and sporadic, for FUS mutations and also suggests that de novo mutations is a relevant mechanism underlying sporadic neurodegenerative disease., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background and Aims: The aim of this study was to evaluate and characterize the feasibility and safety of bone marrow-derived cell (BMC) mobilization following repeated courses of granulocyte-colony stimulating factor (G-CSF) in patients with amyotrophic lateral sclerosis (ALS)., Methods: Between January 2006 and March 2007, 26 ALS patients entered a multicenter trial that included four courses of BMC mobilization at 3-month intervals. In each course, G-CSF (5 microg/kg b.i.d.) was administered for four consecutive days; 18% mannitol was also given. Mobilization was monitored by flow cytometry analysis of circulating CD34(+) cells and by in vitro colony assay for clonogenic progenitors. Co-expression by CD34(+) cells of CD133, CD90, CD184, CD117 and CD31 was also assessed., Results: Twenty patients completed the four-course schedule. One patient died and one refused to continue the program before starting the mobilization courses; four discontinued the study protocol because of disease progression. Overall, 89 G-CSF courses were delivered. There were two severe adverse events: one prolactinoma and one deep vein thrombosis. There were no discontinuations as a result of toxic complications. Circulating CD34(+) cells were monitored during 85 G-CSF courses and were always markedly increased; the range of median peak values was 41-57/microL, with no significant differences among the four G-CSF courses. Circulating clonogenic progenitor levels paralleled CD34(+) cell levels. Most mobilized CD34(+) cells co-expressed stem cell markers, with a significant increase in CD133 co-expression., Conclusions: It is feasible to deliver repeated courses of G-CSF to mobilize a substantial number of CD34(+) cells in patients with ALS; mobilized BMC include immature cells with potential clinical usefulness.