Objective
To define the genetic landscape of amyotrophic lateral sclerosis (ALS) and assess the contribution of possible oligogenic inheritance, we aimed to comprehensively sequence 17 known ALS ...genes in 391 ALS patients from the United States.
Methods
Targeted pooled‐sample sequencing was used to identify variants in 17 ALS genes. Fragment size analysis was used to define ATXN2 and C9ORF72 expansion sizes. Genotype–phenotype correlations were made with individual variants and total burden of variants. Rare variant associations for risk of ALS were investigated at both the single variant and gene level.
Results
A total of 64.3% of familial and 27.8% of sporadic subjects carried potentially pathogenic novel or rare coding variants identified by sequencing or an expanded repeat in C9ORF72 or ATXN2; 3.8% of subjects had variants in >1 ALS gene, and these individuals had disease onset 10 years earlier (p = 0.0046) than subjects with variants in a single gene. The number of potentially pathogenic coding variants did not influence disease duration or site of onset.
Interpretation
Rare and potentially pathogenic variants in known ALS genes are present in >25% of apparently sporadic and 64% of familial patients, significantly higher than previous reports using less comprehensive sequencing approaches. A significant number of subjects carried variants in >1 gene, which influenced the age of symptom onset and supports oligogenic inheritance as relevant to disease pathogenesis. ANN NEUROL 2015;77:100–113
Summary Background Mutations in SOD1 cause 13% of familial amyotrophic lateral sclerosis. In the SOD1 Gly93Ala rat model of amyotrophic lateral sclerosis, the antisense oligonucleotide ISIS 333611 ...delivered to CSF decreased SOD1 mRNA and protein concentrations in spinal cord tissue and prolonged survival. We aimed to assess the safety, tolerability, and pharmacokinetics of ISIS 333611 after intrathecal administration in patients with SOD1 -related familial amyotrophic lateral sclerosis. Methods In this randomised, placebo-controlled, phase 1 trial, we delivered ISIS 333611 by intrathecal infusion using an external pump over 11·5 h at increasing doses (0·15 mg, 0·50 mg, 1·50 mg, 3·00 mg) to four cohorts of eight patients with SOD1 -positive amyotrophic lateral sclerosis (six patients assigned to ISIS 333611, two to placebo in each cohort). We did the randomisation with a web-based system, assigning patients in blocks of four. Patients and investigators were masked to treatment assignment. Participants were allowed to re-enrol in subsequent cohorts. Our primary objective was to assess the safety and tolerability of ISIS 333611. Assessments were done during infusion and over 28 days after infusion. This study was registered with Clinicaltrials.gov , number NCT01041222. Findings Seven of eight (88%) patients in the placebo group versus 20 of 24 (83%) in the ISIS 333611 group had adverse events. The most common events were post-lumbar puncture syndrome (3/8 38% vs 8/24 33%), back pain (4/8 50% vs 4/24 17%), and nausea (0/8 0% vs 3/24 13%). We recorded no dose-limiting toxic effects or any safety or tolerability concerns related to ISIS 333611. No serious adverse events occurred in patients given ISIS 333611. Re-enrolment and re-treatment were also well tolerated. Interpretation This trial is the first clinical study of intrathecal delivery of an antisense oligonucleotide. ISIS 333611 was well tolerated when administered as an intrathecal infusion. Antisense oligonucleotides delivered to the CNS might be a feasible treatment for neurological disorders. Funding The ALS Association, Muscular Dystrophy Association, Isis Pharmaceuticals.
Objective:
To identify the causative gene in an autosomal dominant limb‐girdle muscular dystrophy (LGMD) with skeletal muscle vacuoles.
Methods:
Exome sequencing was used to identify candidate ...mutations in the studied pedigree. Genome‐wide linkage was then used to narrow the list of candidates to a single disease‐associated mutation. Additional pedigrees with dominant or sporadic myopathy were screened for mutations in the same gene (DNAJB6) using exome sequencing. Skeletal muscle from affected patients was evaluated with histochemistry and immunohistochemical stains for dystrophy‐related proteins, SMI‐31, TDP43, and DNAJB6.
Results:
Exome analysis in 3 affected individuals from a family with dominant LGMD and vacuolar pathology identified novel candidate mutations in 22 genes. Linkage analysis excluded all variants except a Phe93Leu mutation in the G/F domain of the DNAJB6 gene, which resides within the LGMD locus at 7q36. Analysis of exome sequencing data from other pedigrees with dominant myopathy identified a second G/F domain mutation (Pro96Arg) in DNAJB6. Affected muscle showed mild dystrophic changes, vacuoles, and abnormal aggregation of proteins, including TDP‐43 and DNAJB6 itself.
Interpretation:
Mutations within the G/F domain of DNAJB6 are a novel cause of dominantly‐inherited myopathy. DNAJB6 is a member of the HSP40/DNAJ family of molecular co‐chaperones tasked with protecting client proteins from irreversible aggregation during protein synthesis or during times of cellular stress. The abnormal accumulation of several proteins in patient muscle, including DNAJB6 itself, suggest that DNAJB6 function is compromised by the identified G/F domain mutations. ANN NEUROL 2012;
ABSTRACT
Introduction: Improved outcome measures are essential to efficiently screen the growing number of potential amyotrophic lateral sclerosis (ALS) therapies. Methods: This longitudinal study of ...100 (70 male) participants with ALS compared Accurate Test of Limb Isometric Strength (ATLIS), using a fixed, wireless load cell, with ALS Functional Rating Scale‐Revised (ALSFRS‐R) and vital capacity (VC). Results: Participants enrolled at 5 U.S. sites. Data were analyzed from 66 participants with complete ATLIS, ALSFRS‐R, and VC data over at least 3 visits. Change in ATLIS was less variable both within‐ and among‐person than change in ALSFRS‐R or VC. Additionally, participants who had normal ALSFRS‐R arm and leg function averaged 12 to 32% below expected strength values measured by ATLIS. Conclusions: ATLIS was more sensitive to change than ALSFRS‐R or VC and could decrease sample size requirements by approximately one‐third. The ability of ATLIS to detect prefunctional change has potential value in early trials. Muscle Nerve 56: 710–715, 2017
Understanding the natural history of familial amyotrophic lateral sclerosis (ALS) caused by SOD1 mutations (ALS
) will provide key information for optimising clinical trials in this patient ...population.
To establish an updated natural history of ALS
.
Retrospective cohort study from 15 medical centres in North America evaluated records from 175 patients with ALS with genetically confirmed SOD1 mutations, cared for after the year 2000.
Age of onset, survival, ALS Functional Rating Scale (ALS-FRS) scores and respiratory function were analysed. Patients with the A4V (Ala-Val) SOD1 mutation (SOD1
), the largest mutation population in North America with an aggressive disease progression, were distinguished from other SOD1 mutation patients (SOD1
) for analysis.
Mean age of disease onset was 49.7±12.3 years (mean±SD) for all SOD1 patients, with no statistical significance between SOD1
and SOD1
(p=0.72, Kruskal-Wallis). Total SOD1 patient median survival was 2.7 years. Mean disease duration for all SOD1 was 4.6±6.0 and 1.4±0.7 years for SOD1
. SOD1
survival probability (median survival 1.2 years) was significantly decreased compared with SOD1
(median survival 6.8 years; p<0.0001, log-rank). A statistically significant increase in ALS-FRS decline in SOD1
compared with SOD1
participants (p=0.02) was observed, as well as a statistically significant increase in ALS-forced vital capacity decline in SOD1
compared with SOD1
(p=0.02).
SOD1
is an aggressive, but relatively homogeneous form of ALS. These SOD1-specific ALS natural history data will be important for the design and implementation of clinical trials in the ALS
patient population.
Objective: Evaluate the safety and tolerability of resistance and endurance exercise in ALS participants as measured by their ability to complete this six-month study. Methods: Participants were ...randomized to Resistance, Endurance, or Stretching/Range of Motion (SROM the exercise regimen prescribed for most ALS patients) exercises. All exercises were performed at home with an individualized regimen designed by a physical therapist trained in ALS management. Primary outcome measures were tolerability of the exercises at 24 weeks defined by 50% of participants completing at least 50% of the prescribed exercise regimen. Secondary outcome measures included the ALSFRS-R, pulmonary FVC, and other measures of ALS function. Results: At 12 and 24 weeks, all three exercise regimens were tolerated according to our pre-specified criteria. Compliance to the prescribed exercise regimen was the highest in the resistance and SROM arms of the study. All three forms of exercise were considered safe as there were no differences in the rates of disease progression among groups. There were no differences in the secondary outcome measures and feasibility for evaluating these measures was successful. In a post-hoc analysis, there was a trend towards fewer falls in the Resistance and Endurance groups. Conclusions: This study demonstrates that SROM, resistance, and endurance exercise are all safe to be performed with the specified regimen without any worsening of outcomes as related to ALS function. All three forms of exercise were tolerated with resistance and SROM exercises showing the highest compliance over the 24 week-period.
Highlights • We performed sequencing of 38 genes in 79 sporadic inclusion body myositis patients (sIBM). • Genetic variants associated with hereditary diseases may be found in sIBM patients but their ...significance is unclear. • Genetic studies in sIBM patients may be clinically helpful in distinguishing hereditary diseases.
Objective
Accumulation of misfolded superoxide dismutase‐1 (SOD1) is a pathological hallmark of SOD1‐related amyotrophic lateral sclerosis (ALS) and is observed in sporadic ALS where its role in ...pathogenesis is controversial. Understanding in vivo protein kinetics may clarify how SOD1 influences neurodegeneration and inform optimal dosing for therapies that lower SOD1 transcripts.
Methods
We employed stable isotope labeling paired with mass spectrometry to evaluate in vivo protein kinetics and concentration of soluble SOD1 in cerebrospinal fluid (CSF) of SOD1 mutation carriers, sporadic ALS participants and controls. A deaminated SOD1 peptide, SDGPVKV, that correlates with protein stability was also measured.
Results
In participants with heterozygous SOD1A5V mutations, known to cause rapidly progressive ALS, mutant SOD1 protein exhibited ~twofold faster turnover and ~ 16‐fold lower concentration compared to wild‐type SOD1 protein. SDGPVKV levels were increased in SOD1A5V carriers relative to controls. Thus, SOD1 mutations impact protein kinetics and stability. We applied this approach to sporadic ALS participants and found that SOD1 turnover, concentration, and SDGPVKV levels are not significantly different compared to controls.
Interpretation
These results highlight the ability of stable isotope labeling approaches and peptide deamidation to discern the influence of disease mutations on protein kinetics and stability and support implementation of this method to optimize clinical trial design of gene and molecular therapies for neurological disorders.
Trial Registration
Clinicaltrials.gov: NCT03449212.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease in which microglia play a significant and active role. Recently, a rare missense variant (p.R47H) in the microglial activating ...gene TREM2 was found to increase the risk of several neurodegenerative diseases, including Alzheimer disease. Whether the p.R47H variant is a risk factor for ALS is not known.
To determine whether p.R47H (rs75932628) in TREM2 is a risk factor for ALS and assess whether TREM2 expression is dysregulated in disease.
Samples of DNA from 923 individuals with sporadic ALS and 1854 healthy control individuals self-reported as non-Hispanic white were collected from ALS clinics in the United States and genotyped for the p.R47H variant in TREM2. Clinical data were obtained on ALS participants for genotype/phenotype correlations. Expression of TREM2 was measured by quantitative polymerase chain reaction and compared in spinal cord samples from 18 autopsied patients with ALS and 12 neurologically healthy controls, as well as from wild-type and transgenic SOD1G93A mice.
Minor allele frequency of rs75932628 and relative expression of TREM2.
The TREM2 variant p.R47H was more common in patients with ALS than in the controls and is therefore a significant risk factor for ALS (odds ratio, 2.40; 95% CI, 1.29-4.15; P = 4.1×10-3). Furthermore, TREM2 expression was increased in spinal cord samples from ALS patients and SOD1G93A mice (P = 2.8×10-4 and P = 2.8×10-9, respectively), confirming dysregulated TREM2 in disease. Expression of TREM2 in the human spinal cord was negatively correlated with survival (P = .04) but not with other phenotypic aspects of disease.
This study demonstrates that the TREM2 p.R47H variant is a potent risk factor for sporadic ALS. To our knowledge, these findings identify the first genetic influence on neuroinflammation in ALS and highlight the TREM2 signaling pathway as a therapeutic target in ALS and other neurodegenerative diseases.
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