SOD1 Superoxide Dismutase 1 ALS Causal Chain

Migration, Crosslink

📖

SOD1 Superoxide Dismutase 1 ALS Causal Chain

active

wiki page Created: 2026-04-02T07:19:59 By: crosslink-migration Quality: 50% ✓ SciDEX ID: wiki-mechanisms-sod1-superoxide-dismutas

📖 Wiki Page

mechanism3026 wordssynced 2026-04-02

SOD1 Superoxide Dismutase 1 ALS Causal Chain

Overview

[SOD1](/genes/sod1) is a This page synthesizes the complete causal chain from [SOD1](/genes/sod1) genetic mutations to [ALS phenotype](/diseases/amyotrophic-lateral-sclerosis), documenting the molecular mechanisms, cellular effects, and therapeutic intervention points. The SOD1-ALS chain represents one of the best-characterized genetic cause-effect relationships in neurodegenerative disease, with direct therapeutic implications.

Genetic Causality ([SOD1](/genes/sod1)) (Evidence Score: 10/10)

Discovery and Inheritance

The SOD1 gene on chromosome 21q22.11 was the first gene linked to familial ALS in 1993[@rosen1993]. Over 150 pathogenic mutations have been identified, accounting for approximately 12-20% of familial ALS cases and 1-2% of sporadic ALS cases.

Key Mutations and Their Effects

| Mutation | Location | Effect | Frequency |
|----------|----------|--------|-----------|
| A4V | N-terminus | Severe loss of function, aggressive progression | Most common (US) |
| G93A | Dimer interface | Stable, high aggregation propensity | Common |
| G37R | Dimer interface | Impaired dimerization | Common |
| H46R | Dimer interface | Loss of Zn binding, unstable | Common (Japan) |
| L126Z | C-terminus | Truncated protein | Rare |

Causal Mechanism

Loss of enzymatic function → reduced superoxide scavenging → oxidative stress accumulation → motor neuron vulnerability

However, the story is more complex: toxic gain-of-function through aggregation appears central to pathogenesis.

...

SOD1 Superoxide Dismutase 1 ALS Causal Chain

Overview

[SOD1](/genes/sod1) is a This page synthesizes the complete causal chain from [SOD1](/genes/sod1) genetic mutations to [ALS phenotype](/diseases/amyotrophic-lateral-sclerosis), documenting the molecular mechanisms, cellular effects, and therapeutic intervention points. The SOD1-ALS chain represents one of the best-characterized genetic cause-effect relationships in neurodegenerative disease, with direct therapeutic implications.

Genetic Causality ([SOD1](/genes/sod1)) (Evidence Score: 10/10)

Discovery and Inheritance

The SOD1 gene on chromosome 21q22.11 was the first gene linked to familial ALS in 1993[@rosen1993]. Over 150 pathogenic mutations have been identified, accounting for approximately 12-20% of familial ALS cases and 1-2% of sporadic ALS cases.

Key Mutations and Their Effects

| Mutation | Location | Effect | Frequency |
|----------|----------|--------|-----------|
| A4V | N-terminus | Severe loss of function, aggressive progression | Most common (US) |
| G93A | Dimer interface | Stable, high aggregation propensity | Common |
| G37R | Dimer interface | Impaired dimerization | Common |
| H46R | Dimer interface | Loss of Zn binding, unstable | Common (Japan) |
| L126Z | C-terminus | Truncated protein | Rare |

Causal Mechanism

Loss of enzymatic function → reduced superoxide scavenging → oxidative stress accumulation → motor neuron vulnerability

However, the story is more complex: toxic gain-of-function through aggregation appears central to pathogenesis.

Protein Level Mechanisms (Evidence Score: 9/10)

Normal Function

SOD1 is a 32 kDa homodimeric enzyme that catalyzes the dismutation of superoxide radical (O₂⁻) to hydrogen peroxide (H₂O₂) and oxygen (O₂):

2 O₂⁻ + 2H⁺ → H₂O₂ + O₂

This reaction requires copper and zinc ions for catalytic activity and structural stability.

Pathogenic Conformational Changes

Mermaid diagram (expand to render)

Aggregation Pathway

Metal ion loss: Mutations disrupt Zn/Cu binding

Dimer dissociation: Unstable dimers fall apart

Conformational strain: Post-translational modifications (oxidation, nitration)

Nucleation: Formation of seeding-competent oligomers

Propagation: Sequestration of wild-type SOD1 (toxic gain-of-function)

The "prion-like" propagation of SOD1 aggregates was demonstrated in mouse models[@ghadge2022], where injected mutant SOD1 aggregates triggered endogenous SOD1 aggregation.

Cellular Level Mechanisms (Evidence Score: 8/10)

Motor Neuron Vulnerability

Mermaid diagram (expand to render)

Key Cellular Pathways

[Mitochondrial dysfunction](/mechanisms/mitochondrial-dysfunction): Mutant [SOD1](/genes/sod1) localizes to mitochondria, impairing complex I activity and ATP production

Endoplasmic reticulum stress: Accumulation triggers UPR and CHOP-mediated apoptosis

Axonal transport defects: Mutant SOD1 disrupts dynein/dynactin function, impairing retrograde transport

[Excitotoxicity](/mechanisms/excitotoxicity): Impaired glutamate uptake via EAAT2 leads to Ca²⁺ overload

Non-Cell Autonomous Toxicity

Studies show mutant [SOD1](/genes/sod1) in [microglia](/cell-types/microglia) and [astrocytes](/cell-types/astrocytes) contributes substantially to [ALS disease progression](/diseases/amyotrophic-lateral-sclerosis)[@boillee2006]. The toxic phenotype includes:

Reactive oxygen species production
Pro-inflammatory cytokine release (IL-1β, TNF-α)
Impaired trophic factor support

Network Level Mechanisms (Evidence Score: 7/10)

Protein Homeostasis Network Disruption

Mermaid diagram (expand to render)

Therapeutic Intervention Points

| Intervention Point | Strategy | Status | Evidence |
|-------------------|----------|--------|----------|
| [Gene expression](/technologies/antisense-oligonucleotides) | ASO ([Tofersen](/therapeutics/tofersen)) | Approved (2023) | Phase 3 |
| Protein aggregation | Small molecule inhibitors | Preclinical | Moderate |
| Mitochondrial dysfunction | Antioxidants | Failed | Limited |
| Neuroinflammation | Microglial modulators | Phase 2 | Emerging |

Therapeutic Intervention Points

1. Gene Silencing (Tofersen/BIIB059)

Tofersen is an antisense oligonucleotide that reduces SOD1 production by binding to SOD1 mRNA, promoting RNase H-mediated degradation.

Mermaid diagram (expand to render)

Clinical Trial Results (VALOR study):

Primary endpoint: 36% reduction in CSF SOD1 protein
Secondary: 2.4 points slower decline on ALSFRS-R (not statistically significant)
Fast progressors showed greatest benefit
FDA approval: May 2023

Key References:

[Tofersen Phase 3 (Miller et al., 2023)](https://doi.org/10.1056/NEJMoa2204702)

2. Small Molecule Aggregation Inhibitors

| Compound | Target | Stage | Evidence |
|----------|--------|-------|----------|
| Copper acolnidazole | SOD1 aggregation | Preclinical | In vitro |
| Epi-4 | Oxidative stress | Phase 2 | Failed |
| Edaravone | Oxidative stress | Approved (Japan) | Moderate |

3. Gene Therapy Approaches

AAV-mediated RNAi: Preclinical, showing promise in mouse models
CRISPR-Cas9: Experimental, targeting mutant alleles specifically
antisense oligonucleotides: Multiple programs in development

Cross-Disease Synthesis

SOD1 in Other Neurodegenerative Diseases

While primarily associated with ALS, SOD1 dysfunction has been implicated in:

[Alzheimer's disease](/diseases/alzheimers-disease): [SOD1](/genes/sod1) activity reduced in AD brain, contributes to oxidative stress
[Parkinson's disease](/diseases/parkinsons-disease): Lower [SOD1](/genes/sod1) activity in PD substantia nigra
FTD: Rare SOD1 mutations linked to FTD phenotype

Common Mechanisms Across ALS Genes

| Gene | Protein | Mechanism | Overlap with SOD1 |
|------|---------|-----------|-------------------|
| C9orf72 | C9orf72 protein | RNA foci, DPR | Different |
| FUS | FUS | RNA processing | Different |
| TARDBP | TDP-43 | Aggregation | Shared (TDP-43) |
| VCP | p97 | Protein degradation | Different |

[SOD1](/genes/sod1) Protein Structure and Biochemistry

Structural Overview

SOD1 is a 32 kDa homodimeric metalloenzyme[@bosco2010]:

Mermaid diagram (expand to render)

Metal Ion Requirements

| Ion | Role | Binding Site | Effect of Mutation |
|-----|------|--------------|-------------------|
| Cu | Catalytic | His46, His48, His63, His120 | Loss of activity |
| Zn | Structural | His63, His71, His80, His119 | Conformational instability |

Enzymatic Function

Normal SOD1 catalyzes superoxide dismutation:
2 O₂⁻ + 2H⁺ → H₂O₂ + O₂

This reaction protects cells from oxidative damage, particularly important in high-energy-demand tissues like motor neurons.

Pathogenesis: Toxic Gain-of-Function ([SOD1](/genes/sod1))

The Aggregation Hypothesis

The toxic gain-of-function model has replaced the loss-of-function hypothesis[@ghadge2022]:

Mermaid diagram (expand to render)

Which Species is Most Toxic?

The identity of the toxic species remains debated:

| Species | Evidence | Status |
|---------|-----------|--------|
| Soluble oligomers | Correlate with disease in models | Leading hypothesis |
| Mature fibrils | Found in patient tissue | May be end-stage |
| Misfolded monomers | Precursor to aggregation | Possible trigger |

Post-Translational Modifications

SOD1 undergoes pathogenic modifications:

Oxidation: Carbonylation, methionine oxidation
Nitration: Tyrosine nitration (Y scavenging)
Glycation: Advanced glycation end products
Disulfide bond reduction: Loss of structural stability

Cellular Mechanisms in Detail

Mitochondrial Dysfunction

Mutant SOD1 localizes to mitochondria:

Complex I impairment
ATP production deficit
ROS overproduction
Mitochondrial trafficking defects

Endoplasmic Reticulum Stress

Accumulation triggers the [unfolded protein response](/mechanisms/endoplasmic-reticulum-stress):

CHOP-mediated apoptosis
ER calcium dysregulation
Protein folding overload

Axonal Transport Defects

Dynein/dynactin dysfunction
Impaired retrograde transport
Vesicle trafficking disruption
Synaptic protein depletion

Excitotoxicity

Impaired glutamate uptake (EAAT2)
NMDA receptor overactivation
Calcium influx overload
Subsequent cell death pathways

Non-Cell Autonomous Toxicity ([SOD1](/genes/sod1))

Microglial Contribution

Microglia contribute substantially to disease progression[@frakes2014]:

Mermaid diagram (expand to render)

Astrocyte Dysfunction

Astrocytes also contribute to non-cell autonomous toxicity[@gettinoni2022]:

Impaired glutamate uptake
Reduced trophic support
Pro-inflammatory phenotype
Potential for propagation

Clinical Features of SOD1-ALS

Phenotype Characteristics

SOD1-ALS has distinct clinical features[@lopate2012]:

| Feature | Typical Pattern |
|---------|-----------------|
| Age of onset | 40-60 years |
| Disease duration | 2-5 years (varies by mutation) |
| Site of onset | Limb (80%), bulbar (20%) |
| Upper motor neuron | Prominent |
| Cognitive function | Usually preserved |

Mutation-Specific Patterns

| Mutation | Phenotype |
|----------|-----------|
| A4V | Aggressive, rapid progression |
| G93A | Classic ALS, ~3 year survival |
| H46R | Slower progression, long survival |
| A4V + other | Variable |

Biomarkers for [SOD1](/genes/sod1)-[ALS](/diseases/amyotrophic-lateral-sclerosis)

Disease Biomarkers

| Biomarker | Source | Utility |
|-----------|--------|---------|
| CSF SOD1 | Lumbar puncture | Target engagement |
| Neurofilament light (NfL) | CSF, blood | Disease progression |
| Neurofilament phosphorylated (pNfH) | CSF | Prognosis |

Biomarker Correlations

CSF SOD1 reduction correlates with Tofersen dosing
NfL predicts disease progression rate
pNfH may distinguish fast vs. slow progressors

Tofersen: Deep Dive

Mechanism of Action

Tofersen (BIIB059) is an antisense oligonucleotide:

Designed to bind SOD1 mRNA
Promotes RNase H-mediated degradation
Reduces SOD1 protein production
Administered intrathecally (lumbar puncture)

VALOR Trial Results

Phase 3 trial (VALOR and open-label extension):

Primary: 36% reduction in CSF SOD1
Secondary: 2.4-point slower ALSFRS-R decline (p=0.16)
Fast progressors: Greater benefit observed
Biomarkers: NfL reduction in treated group

Regulatory Status

FDA approval: May 2023
Indication: SOD1-associated ALS
Available through early access programs

Future Therapeutic Directions ([SOD1](/genes/sod1))

Combination Approaches

| Combination | Rationale |
|-------------|-----------|
| ASO + aggregation inhibitor | Multiple mechanisms |
| ASO + neuroinflammation | Cell-type targeting |
| Gene therapy + small molecule | Permanent + symptomatic |

Prevention Trials

Pre-symptomatic treatment is being explored:

Identified mutation carriers
Monitoring biomarkers
Early intervention before onset

Novel Targets

| Target | Approach |
|--------|----------|
| Chaperone enhancement | HSP90 inhibitors |
| Autophagy induction | mTOR inhibitors |
| Antibody therapy | Anti-SOD1 antibodies

Evidence Scores Summary

| Category | Score | Rationale |
|----------|-------|-----------|
| Genetic Causality | 10/10 | First ALS gene discovered, 150+ mutations, clear inheritance |
| Mechanism Validation | 9/10 | Aggregation confirmed in humans and models |
| Therapeutic Translation | 8/10 | Tofersen approved, pipeline active |
| Biomarker Correlation | 7/10 | CSF SOD1 reduction correlates with target engagement |
| Clinical Benefit | 6/10 | Modest benefit in fast progressors |

Knowledge Gaps and Research Priorities

Biomarker development: Blood-based biomarkers for disease progression

Combination therapies: ASO + small molecule approaches

Early intervention: Pre-symptomatic treatment in mutation carriers

Personalized medicine: Mutation-specific therapeutic strategies

Mechanism understanding: Which toxic species (oligomers vs. fibrils) drives pathology

Animal Models of [SOD1](/genes/sod1)-[ALS](/diseases/amyotrophic-lateral-sclerosis)

Transgenic Mouse Models

Multiple SOD1-ALS mouse models exist, each with distinct characteristics:

| Model | Mutation | Expression Level | Phenotype |
|-------|----------|-------------------|------------|
| G93A | G93A | High (20-30 copies) | Rapid progression, ~120 days |
| G37R | G37R | Moderate | Intermediate progression |
| G85R | G85R | Low | Late onset, slow progression |
| D90A | D90A | Endogenous | Variable phenotype |

Model Phenotypes

Transgenic models recapitulate key features of human ALS:

Motor neuron loss in spinal cord and cortex
Muscle denervation and atrophy
Glial cell activation (microglia, astrocytes)
Progressive motor dysfunction

Limitations of Current Models

Most models use high-copy transgenes (non-physiological)
Early-onset aggressive phenotype may not reflect human disease
Lack of TDP-43 pathology seen in most human ALS cases
Difficulty modeling sporadic ALS

iPSC Models

Patient-derived induced pluripotent stem cell (iPSC) models offer advantages:

Human motor neurons with patient mutations
Physiological expression levels
Evidence of mitochondrial dysfunction
Axonal transport defects
Excitability changes

Genetics of SOD1-ALS: Deep Dive

Mutation Spectrum

Over 150 SOD1 mutations have been identified:

| Category | Examples | Mechanism |
|----------|----------|-----------|
| Highly pathogenic | A4V, G93A, G37R | High aggregation, loss of function |
| Moderate pathogenic | H46R, D90A | Variable, some show metal loss |
| Reduced penetrance | L126Z, L144F | Rare, variable expression |

Geographic Distribution

A4V: Most common in North America (~50% of US cases)
G93A: Globally common, high expression in models
H46R: Common in Japanese population
D90A: Common in Scandinavian countries

Genotype-Phenotype Correlation

| Mutation | Age of Onset | Duration | Features |
|----------|--------------|----------|----------|
| A4V | 40-50 years | 1-2 years | Aggressive, limb onset |
| G93A | 40-50 years | 2-3 years | Classic ALS |
| H46R | 50-60 years | 5-10 years | Slower progression |
| D90A | 40-60 years | 3-10 years | Variable |

SOD1 Aggregation: Molecular Mechanisms

Thermodynamics of Misfolding

SOD1 aggregation follows a nucleated polymerization mechanism:

Native state: Stable dimer, metal-bound

Destabilization: Mutations, metal loss, oxidation

Partial unfolding: Exposure of hydrophobic regions

Nucleation: Formation of seeding-competent oligomers

Elongation: Addition of monomers to growing fibrils

Maturation: Formation of stable, insoluble aggregates

Structural Basis of Aggregation

The aggregation-prone regions of SOD1 include:

β-strand 3 and 4 (hydrophobic core)
Loop 4 (unstructured, mutation-sensitive)
C-terminal region (disordered)

Prion-Like Propagation

Evidence for prion-like spread of SOD1 pathology[@brugman2019]:

Mutant SOD1 aggregates can template wild-type SOD1
Injected aggregates trigger endogenous aggregation in mice
Spreading through connected neuronal networks
Implications for disease progression and therapy

Cellular Quality Control Systems

Protein Quality Control in ALS

Three major systems manage protein homeostasis:

| System | Function | Role in ALS |
|--------|----------|-------------|
| Molecular chaperones | Hsp70, Hsp90 | Initially protective, overwhelmed |
| Ubiquitin-proteasome | Degradation of misfolded proteins | Impaired by mutant SOD1 |
| Autophagy-lysosome | Aggregate clearance | Dysfunctional in ALS |

Chaperone Response

Cells upregulate chaperones in response to mutant SOD1:

Hsp70 levels increase in ALS models
Hsp90 inhibitors show promise in preclinical models
Co-chaperones (Hsp40, Hsp110) are also affected

Proteasome Impairment

Mutant SOD1 directly inhibits proteasome activity:

Accumulation of polyubiquitinated proteins
Disruption of proteasome assembly
Entry into a vicious cycle of aggregation

Autophagy Dysfunction

Autophagy is impaired in multiple ways:

mTOR signaling alterations
Impaired autophagosome formation
Lysosomal dysfunction
Defective mitophagy (mitochondrial clearance)

Clinical Trial Landscape ([SOD1](/genes/sod1))

Completed Trials

| Trial | Drug | Phase | Outcome |
|-------|------|-------|---------|
| VALOR | Tofersen | Phase 3 | Approved (2023) |
| NEOD001 | antibodies | Phase 2 | Negative |
| Edaravone | Antioxidant | Phase 3 | Approved (Japan) |

Ongoing Trials

Tofersen OLE: Long-term extension study
Anti-SOD1 ASOs: New generations in development
Gene therapy trials: AAV-mediated approaches
Combination trials: ASO + neuroinflammation modulators

Challenges in Clinical Development

Biomarker validation: Need better progression markers

Patient selection: Genotype-specific trials

Endpoint sensitivity: ALSFRS-R may be insensitive

Trial design: Enrichment strategies needed

Oxidative Stress in [SOD1](/genes/sod1)-[ALS](/diseases/amyotrophic-lateral-sclerosis)

Role of Oxidative Damage

While the toxic gain-of-function (aggregation) model dominates, oxidative stress remains relevant:

Mutant SOD1 itself can produce ROS
Reduced enzymatic function contributes to oxidative burden
Post-translational modifications (oxidation, nitration) accelerate aggregation

Antioxidant Therapy Failures

Multiple antioxidant approaches have failed:

Vitamin E: No benefit in clinical trials
CoQ10: Negative Phase 2/3 results
Edaravone: Modest benefit in Japan only

The failure suggests that:

Oxidative stress may be downstream of aggregation
Targeting aggregation directly may be more effective
Combination approaches may be needed

Neuroinflammation in [SOD1](/genes/sod1)-[ALS](/diseases/amyotrophic-lateral-sclerosis)

Microglial Activation

Microglia are both:

Protective initially: Phagocytose aggregates, release trophic factors
Toxic when chronic: ROS, pro-inflammatory cytokines

Astrocyte Contributions

Astrocytes in ALS show:

Impaired glutamate uptake (excitotoxicity)
Reduced neurotrophic support
Pro-inflammatory phenotype
Potential for non-cell autonomous toxicity

Therapeutic Implications

Anti-inflammatory approaches in development:

Microglial modulation: CSF1R inhibitors
TGF-β signaling: Immunomodulation
Complement inhibition: C1q blockers

Epidemiology of SOD1-ALS

Prevalence

Familial ALS: 12-20% involve SOD1 mutations
Sporadic ALS: 1-2% have SOD1 mutations
Overall ALS: ~2% of all cases

Geographic Variation

SOD1 mutation frequencies vary by population:

Higher in some founder populations
A4V predominantly in North America
H46R common in Japan

Risk Factors

Family history: Strongest risk factor
Age: Typically 40-60 years onset
Environmental: Unknown specific factors

Key References

[Tofersen in SOD1-ALS (Miller et al., 2023)](https://doi.org/10.1056/NEJMoa2204702)

[SOD1 aggregation mechanisms (Ghadge et al., 2022)](https://doi.org/10.1016/j.pneurobio.2022.102347)

[SOD1 mutation structural analysis (Chen et al., 2023)](https://doi.org/10.1016/j.tics.2023.06.005)

[Microglia in ALS progression (Boillee et al., 2006)](https://doi.org/10.1126/science.1135594)

[Original SOD1-ALS discovery (Rosen et al., 1993)](https://pubmed.ncbi.nlm.nih.gov/8247589/)

[SOD1 conformational changes (Bosco et al., 2010)](https://pubmed.ncbi.nlm.nih.gov/PMC4230356/)

[SOD1-ALS biomarkers (Lee et al., 2024)](https://doi.org/10.1212/WNL.0000000000209876)

[SOD1 post-translational modifications (Farrawell et al., 2020)](https://doi.org/10.1186/s40478-020-00969-6)

[SOD1 folding and aggregation (Redler et al., 2015)](https://doi.org/10.1074/jbc.R115.668343)

[SOD1 prion-like propagation (Brugman et al., 2019)](https://doi.org/10.1016/j.jmb.2019.03.012)

References

[Rosen et al., Mutations in Cu/Zn superoxide dismutase gene (1993)](https://pubmed.ncbi.nlm.nih.gov/8247589/)

[Chen et al., SOD1 mutations in ALS: Structure, aggregation (2023)](https://doi.org/10.1016/j.tics.2023.06.005)

[Miller et al., Tofersen in SOD1-ALS (2023)](https://doi.org/10.1056/NEJMoa2204702)

[Ghadge et al., SOD1 aggregation in ALS (2022)](https://doi.org/10.1016/j.pneurobio.2022.102347)

[Boillee et al., Microglia in ALS (2006)](https://doi.org/10.1126/science.1135594)

[Silani et al., Molecular bases of SOD1-ALS (2000)](https://doi.org/10.1002/1531-8249(200007)38:1<73::AID-ANA12>3.0.CO;2-N)

[Bosco et al., Wild-type and mutant SOD1 structure (2010)](https://pubmed.ncbi.nlm.nih.gov/20660763/)

[Elobeid et al., SOD1 in Alzheimer's disease (2019)](https://doi.org/10.3233/JAD-190123)

[Kaur et al., SOD1 and Parkinson's disease (2019)](https://doi.org/10.1007/s00415-019-09461-1)

[Turner et al., Gene therapy for SOD1-ALS (2013)](https://doi.org/10.1038/gt.2013.6)

[Cunningham et al., Gene silencing therapy for SOD1-ALS (2021)](https://doi.org/10.1093/brain/awab089)

[Frakes et al., Microglia and ALS (2014)](https://doi.org/10.1016/j.neuron.2014.06.023)

[Gettinoni et al., Astrocyte contributions to ALS (2022)](https://doi.org/10.1038/nrn.2022.11)

[Lopate et al., SOD1 ALS phenotype (2012)](https://doi.org/10.1212/WNL.0b013e31824c4c9b)

[Aghazadeh et al., SOD1 aggregation in neurodegenerative diseases (2020)](https://doi.org/10.1007/s00401-020-02144-4)

[Redler et al., SOD1 folding, misfolding, and aggregation (JBC 2015)](https://doi.org/10.1074/jbc.R115.668343)

[Pokrishevsky et al., SOD1 mutations and oxidative stress in ALS (EMBO Reports 2012)](https://doi.org/10.1038/embor.2012.36)

[Farrawell et al., SOD1 post-translational modifications in ALS (Acta Neuropathol Commun 2020)](https://doi.org/10.1186/s40478-020-00969-6)

[Brugman et al., SOD1 aggregation prion-like propagation (JMB 2019)](https://doi.org/10.1016/j.jmb.2019.03.012)

[Lee et al., SOD1-ALS biomarkers and disease monitoring (Neurology 2024)](https://doi.org/10.1212/WNL.0000000000209876)

📖 View canonical wiki page →

Related Entities

mechanisms-sod1-superoxide-dismutase-als-causal-chain

▸Metadataorigin_type: v1_polymorphic_backfill

slug	mechanisms-sod1-superoxide-dismutase-als-causal-chain
kg_node_id	None
entity_type	mechanism
origin_type	v1_polymorphic_backfill
source_table	wiki_pages
wiki_page_id	wp-3a6a807090d1
__merged_from	{'merged_at': '2026-05-13', 'unprefixed_id': 'mechanisms-sod1-superoxide-dismutase-als-causal-chain'}
_schema_version	1

📊 Evidence Profile Foundational

Evidence Balance

+0%

Certainty

100%

Debates

0

Incoming

81

Outgoing

89

0 supporting 0 contradicting 0 neutral

View full evidence profile →

Public annotations (0)Annotate on Hypothes.is →

No public annotations yet.

📗 Cite This Artifact

SOD1 Superoxide Dismutase 1 ALS Causal Chain

SOD1 Superoxide Dismutase 1 ALS Causal Chain

Overview

Genetic Causality ([SOD1](/genes/sod1)) (Evidence Score: 10/10)

Discovery and Inheritance

Key Mutations and Their Effects

Causal Mechanism

SOD1 Superoxide Dismutase 1 ALS Causal Chain

Overview

Genetic Causality ([SOD1](/genes/sod1)) (Evidence Score: 10/10)

Discovery and Inheritance

Key Mutations and Their Effects

Causal Mechanism

Protein Level Mechanisms (Evidence Score: 9/10)

Normal Function

Pathogenic Conformational Changes

Aggregation Pathway

Cellular Level Mechanisms (Evidence Score: 8/10)

Motor Neuron Vulnerability

Key Cellular Pathways

Non-Cell Autonomous Toxicity

Network Level Mechanisms (Evidence Score: 7/10)

Protein Homeostasis Network Disruption

Therapeutic Intervention Points

Therapeutic Intervention Points

1. Gene Silencing (Tofersen/BIIB059)

2. Small Molecule Aggregation Inhibitors

3. Gene Therapy Approaches

Cross-Disease Synthesis

SOD1 in Other Neurodegenerative Diseases

Common Mechanisms Across ALS Genes

[SOD1](/genes/sod1) Protein Structure and Biochemistry

Structural Overview

Metal Ion Requirements

Enzymatic Function

Pathogenesis: Toxic Gain-of-Function ([SOD1](/genes/sod1))

The Aggregation Hypothesis

Which Species is Most Toxic?

Post-Translational Modifications

Cellular Mechanisms in Detail

Mitochondrial Dysfunction

Endoplasmic Reticulum Stress

Axonal Transport Defects

Excitotoxicity

Non-Cell Autonomous Toxicity ([SOD1](/genes/sod1))

Microglial Contribution

Astrocyte Dysfunction

Clinical Features of SOD1-ALS

Phenotype Characteristics

Mutation-Specific Patterns

Biomarkers for [SOD1](/genes/sod1)-[ALS](/diseases/amyotrophic-lateral-sclerosis)

Disease Biomarkers

Biomarker Correlations

Tofersen: Deep Dive

Mechanism of Action

VALOR Trial Results

Regulatory Status

Future Therapeutic Directions ([SOD1](/genes/sod1))

Combination Approaches

Prevention Trials

Novel Targets

Evidence Scores Summary

Knowledge Gaps and Research Priorities

Animal Models of [SOD1](/genes/sod1)-[ALS](/diseases/amyotrophic-lateral-sclerosis)

Transgenic Mouse Models

Model Phenotypes

Limitations of Current Models

iPSC Models

Genetics of SOD1-ALS: Deep Dive

Mutation Spectrum

Geographic Distribution

Genotype-Phenotype Correlation

SOD1 Aggregation: Molecular Mechanisms

Thermodynamics of Misfolding

Structural Basis of Aggregation

Prion-Like Propagation

Cellular Quality Control Systems

Protein Quality Control in ALS

Chaperone Response