◆

Subtypes

3

ARSACS

Autosomal recessive spastic ataxia of Charlevoix-Saguenay is a paradigmatic spastic-ataxia disorder with severe white-matter involvement.

Show evidence (1 reference)

DOI:10.1007/s00415-024-12505-y SUPPORT

"Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) and Spastic Paraplegia Type 7 (SPG7) are paradigmatic spastic ataxias (SPAX) with suggested white matter (WM) involvement."

This directly supports ARSACS as a core subtype anchoring the SPAX syndrome concept.

SPG7-associated spastic ataxia

SPG7-associated disease is another paradigmatic spastic-ataxia subtype, generally showing milder white-matter injury than ARSACS.

Show evidence (1 reference)

DOI:10.1007/s00415-024-12505-y SUPPORT

"Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) and Spastic Paraplegia Type 7 (SPG7) are paradigmatic spastic ataxias (SPAX) with suggested white matter (WM) involvement."

This directly supports SPG7-associated disease as another core subtype within the syndrome.

SPAX5

AFG3L2-related spastic ataxia type 5 is a severe mitochondrial subtype with integrated stress-response activation.

Show evidence (1 reference)

DOI:10.1093/brain/awad340 SUPPORT

"Heterozygous AFG3L2 mutations cause spinocerebellar ataxia type 28 (SCA28) or dominant optic atrophy type 12 (DOA12), while biallelic AFG3L2 mutations result in the rare and severe spastic ataxia type 5 (SPAX5)."

This directly supports SPAX5 as a defined genetic subtype relevant to the broader syndrome.

⚙

Pathophysiology

3

Genetically Heterogeneous Spastic-Ataxia Syndrome

The syndrome represents a clinically coherent but genetically diverse neurodegenerative phenotype in which ataxia and pyramidal-spastic features co-occur.

Downstream

White Matter Degeneration and Secondary Demyelination Several paradigmatic subtypes share white-matter injury and neurodegenerative propagation.

Mitochondrial Proteotoxic Stress Signaling Some subtypes, especially SPAX5, are driven by mitochondrial proteostasis failure.

Show evidence (1 reference)

PMID:23033504 SUPPORT

"Although the combined presence of ataxia and pyramidal features has a long differential, the presence of a true spastic-ataxia as the predominant clinical syndrome has a rather limited differential diagnosis."

This directly supports the syndrome as a recognizable spastic-ataxia clinical entity.

White Matter Degeneration and Secondary Demyelination

In paradigmatic SPAX disorders, especially ARSACS, widespread white matter damage with secondary demyelination contributes to the spastic-ataxic phenotype.

oligodendrocyte link neuron link

myelination link ⚠ ABNORMAL central nervous system myelination link ↓ DECREASED

Downstream

Ataxia White-matter and cerebellar system injury contribute to the core ataxic phenotype.

Spasticity Pyramidal tract dysfunction contributes to spastic clinical features.

Gait Ataxia Combined cerebellar and pyramidal-system injury produces gait impairment.

Show evidence (1 reference)

DOI:10.1007/s00415-024-12505-y SUPPORT

"In ARSACS, but not SPG7 patients, we observed a complex and multi-faced involvement of brain WM, with a clinically meaningful widespread loss of axonal and dendritic integrity, secondary demyelination and, overall, a reduction in cellularity and volume."

This directly supports white-matter degeneration and secondary demyelination as a mechanistic branch in spastic ataxia.

Mitochondrial Proteotoxic Stress Signaling

In the SPAX5 subtype, biallelic AFG3L2 dysfunction causes mitochondrial proteotoxic stress and activates the OMA1-DELE1-HRI integrated stress response pathway.

fibroblast link Purkinje cell link

AFG3L2 link

Downstream

Ataxia Purkinje neuron and cerebellar dysfunction produce ataxia.

Spasticity Mitochondrial neurodegeneration in SPAX5 includes spastic features.

Show evidence (1 reference)

DOI:10.1093/brain/awad340 SUPPORT In Vitro

"In this work, we demonstrated that mitochondrial proteotoxicity in the absence/mutation of AFG3L2 activates the OMA1-DELE1-HRI pathway eliciting the integrated stress response."

This directly supports a subtype-specific mitochondrial stress mechanism within the spastic-ataxia syndrome family.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

●

Phenotypes

6

Musculoskeletal 1

Spasticity VERY_FREQUENT Spasticity (HP:0001257)

Show evidence (1 reference)

PMID:23033504 SUPPORT

"Although the combined presence of ataxia and pyramidal features has a long differential, the presence of a true spastic-ataxia as the predominant clinical syndrome has a rather limited differential diagnosis."

This directly supports pyramidal or spastic features as a defining syndrome component.

Nervous System 4

Ataxia VERY_FREQUENT Ataxia (HP:0001251)

Show evidence (1 reference)

PMID:23033504 SUPPORT

"Although the combined presence of ataxia and pyramidal features has a long differential, the presence of a true spastic-ataxia as the predominant clinical syndrome has a rather limited differential diagnosis."

This directly supports ataxia as one of the two defining syndrome elements.

Gait Ataxia VERY_FREQUENT Gait ataxia (HP:0002066)

Show evidence (1 reference)

clinicaltrials:NCT06261424 PARTIAL

"Spastic ataxias are a group of diseases causing symptoms such as walking difficulties and balance impairments that lead to a high risk of falls."

This directly supports gait and balance impairment as a major functional phenotype across spastic ataxias.

Dysarthria Dysarthria (HP:0001260)

Dystonia OCCASIONAL Dystonia (HP:0001332)

Show evidence (1 reference)

DOI:10.1093/brain/awad340 SUPPORT Human Clinical

"The clinical spectrum of SPAX5 includes childhood-onset cerebellar ataxia, spasticity, dystonia and myoclonic epilepsy."

This directly supports dystonia in the SPAX5 subtype.

Other 1

Myoclonic Epilepsy OCCASIONAL Myoclonic seizure (HP:0032794)

Show evidence (1 reference)

DOI:10.1093/brain/awad340 SUPPORT Human Clinical

"The clinical spectrum of SPAX5 includes childhood-onset cerebellar ataxia, spasticity, dystonia and myoclonic epilepsy."

This directly supports myoclonic epilepsy in the SPAX5 subtype.

🧬

Genetic Associations

3

AFG3L2 (Causal biallelic variant)

Show evidence (1 reference)

DOI:10.1093/brain/awad340 SUPPORT

"Heterozygous AFG3L2 mutations cause spinocerebellar ataxia type 28 (SCA28) or dominant optic atrophy type 12 (DOA12), while biallelic AFG3L2 mutations result in the rare and severe spastic ataxia type 5 (SPAX5)."

This directly supports AFG3L2 as a causal gene within the syndrome spectrum.

SACS (Causal biallelic variant)

Show evidence (1 reference)

PMID:23033504 SUPPORT Human Clinical

"Autosomal recessive ataxia of Charlevoix-Saguenay, late-onset Friedreich ataxia, and hereditary spastic paraplegia type 7 are examples of genetic diseases with such a prominent spastic-ataxic syndrome as the clinical hallmark."

This supports ARSACS, the SACS-related disease, as a genetic cause of the spastic-ataxia syndrome.

SPG7 (Causal biallelic variant)

Show evidence (1 reference)

PMID:23033504 SUPPORT Human Clinical

"Autosomal recessive ataxia of Charlevoix-Saguenay, late-onset Friedreich ataxia, and hereditary spastic paraplegia type 7 are examples of genetic diseases with such a prominent spastic-ataxic syndrome as the clinical hallmark."

This directly supports hereditary spastic paraplegia type 7 as a genetic disease with a prominent spastic-ataxic syndrome.

💊

Treatments

2

Supervised rehabilitation program

Action: physical therapy MAXO:0000011

Disease-specific rehabilitation is under active clinical evaluation for spastic ataxias.

Show evidence (1 reference)

clinicaltrials:NCT06261424 SUPPORT

"The three objectives of this project are: 1) to determine the effect of a 12-week rehabilitation program on disease severity as compared with usual care for individuals with spastic ataxias;"

This directly supports rehabilitation as a disease-relevant intervention under formal study.

Aerobic exercise-based rehabilitation

Action: aerobic exercise therapy MAXO:0000065

The IMPACT program is a structured exercise-based rehabilitation approach targeting gait, balance, and disease severity.

Show evidence (1 reference)

clinicaltrials:NCT06261424 SUPPORT

"The team has developed the program to specifically target symptoms present in these patients and was previously pilot-tested."

This supports structured exercise-oriented rehabilitation for the symptomatic treatment of spastic ataxias.

🔬

Clinical Trials

1

NCT06261424 NOT_APPLICABLE ACTIVE_NOT_RECRUITING

A randomized controlled rehabilitation study testing a supervised 12-week program for spastic ataxias.

Show evidence (1 reference)

clinicaltrials:NCT06261424 SUPPORT

"The three objectives of this project are: 1) to determine the effect of a 12-week rehabilitation program on disease severity as compared with usual care for individuals with spastic ataxias;"

This directly supports a disease-relevant interventional clinical trial in spastic ataxias.

{ }

Source YAML

click to show

name: Spasticity-Ataxia-Gait Anomalies Syndrome
creation_date: "2026-04-23T00:00:00Z"
updated_date: "2026-04-24T00:00:00Z"
description: >-
  Spasticity-ataxia-gait anomalies syndrome is best supported in the literature
  as a heterogeneous spastic-ataxia (SPAX) syndrome concept defined by the
  coexistence of cerebellar ataxia, pyramidal or spastic features, and gait
  impairment. The syndrome spans multiple gene-defined neurodegenerative
  disorders, including ARSACS, SPG7-associated spastic ataxia, and SPAX5.
category: Neurological Disorder
parents:
  - hereditary disease
  - neurological disorder
disease_term:
  preferred_term: spasticity-ataxia-gait anomalies syndrome
  term:
    id: MONDO:0014803
    label: spasticity-ataxia-gait anomalies syndrome
has_subtypes:
  - name: ARSACS
    description: >-
      Autosomal recessive spastic ataxia of Charlevoix-Saguenay is a paradigmatic
      spastic-ataxia disorder with severe white-matter involvement.
    evidence:
      - reference: DOI:10.1007/s00415-024-12505-y
        reference_title: >-
          An MRI evaluation of white matter involvement in paradigmatic forms of
          spastic ataxia: results from the multi-center PROSPAX study
        supports: SUPPORT
        snippet: >-
          Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS)
          and Spastic Paraplegia Type 7 (SPG7) are paradigmatic spastic ataxias
          (SPAX) with suggested white matter (WM) involvement.
        explanation: >-
          This directly supports ARSACS as a core subtype anchoring the SPAX
          syndrome concept.
  - name: SPG7-associated spastic ataxia
    description: >-
      SPG7-associated disease is another paradigmatic spastic-ataxia subtype,
      generally showing milder white-matter injury than ARSACS.
    evidence:
      - reference: DOI:10.1007/s00415-024-12505-y
        reference_title: >-
          An MRI evaluation of white matter involvement in paradigmatic forms of
          spastic ataxia: results from the multi-center PROSPAX study
        supports: SUPPORT
        snippet: >-
          Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS)
          and Spastic Paraplegia Type 7 (SPG7) are paradigmatic spastic ataxias
          (SPAX) with suggested white matter (WM) involvement.
        explanation: >-
          This directly supports SPG7-associated disease as another core
          subtype within the syndrome.
  - name: SPAX5
    description: >-
      AFG3L2-related spastic ataxia type 5 is a severe mitochondrial subtype
      with integrated stress-response activation.
    evidence:
      - reference: DOI:10.1093/brain/awad340
        reference_title: Sustained OMA1-mediated integrated stress response is beneficial for spastic ataxia type 5
        supports: SUPPORT
        snippet: >-
          Heterozygous AFG3L2 mutations cause spinocerebellar ataxia type 28
          (SCA28) or dominant optic atrophy type 12 (DOA12), while biallelic
          AFG3L2 mutations result in the rare and severe spastic ataxia type 5
          (SPAX5).
        explanation: >-
          This directly supports SPAX5 as a defined genetic subtype relevant to
          the broader syndrome.
pathophysiology:
  - name: Genetically Heterogeneous Spastic-Ataxia Syndrome
    description: >-
      The syndrome represents a clinically coherent but genetically diverse
      neurodegenerative phenotype in which ataxia and pyramidal-spastic
      features co-occur.
    evidence:
      - reference: PMID:23033504
        reference_title: Reviewing the genetic causes of spastic-ataxias.
        supports: SUPPORT
        snippet: >-
          Although the combined presence of ataxia and pyramidal features has a
          long differential, the presence of a true spastic-ataxia as the
          predominant clinical syndrome has a rather limited differential
          diagnosis.
        explanation: >-
          This directly supports the syndrome as a recognizable spastic-ataxia
          clinical entity.
    downstream:
      - target: White Matter Degeneration and Secondary Demyelination
        description: Several paradigmatic subtypes share white-matter injury and neurodegenerative propagation.
      - target: Mitochondrial Proteotoxic Stress Signaling
        description: Some subtypes, especially SPAX5, are driven by mitochondrial proteostasis failure.
  - name: White Matter Degeneration and Secondary Demyelination
    description: >-
      In paradigmatic SPAX disorders, especially ARSACS, widespread white
      matter damage with secondary demyelination contributes to the
      spastic-ataxic phenotype.
    cell_types:
      - preferred_term: oligodendrocyte
        term:
          id: CL:0000128
          label: oligodendrocyte
      - preferred_term: neuron
        term:
          id: CL:0000540
          label: neuron
    biological_processes:
      - preferred_term: myelination
        term:
          id: GO:0042552
          label: myelination
        modifier: ABNORMAL
      - preferred_term: central nervous system myelination
        term:
          id: GO:0022010
          label: central nervous system myelination
        modifier: DECREASED
    evidence:
      - reference: DOI:10.1007/s00415-024-12505-y
        reference_title: >-
          An MRI evaluation of white matter involvement in paradigmatic forms of
          spastic ataxia: results from the multi-center PROSPAX study
        supports: SUPPORT
        snippet: >-
          In ARSACS, but not SPG7 patients, we observed a complex and
          multi-faced involvement of brain WM, with a clinically meaningful
          widespread loss of axonal and dendritic integrity, secondary
          demyelination and, overall, a reduction in cellularity and volume.
        explanation: >-
          This directly supports white-matter degeneration and secondary
          demyelination as a mechanistic branch in spastic ataxia.
    downstream:
      - target: Ataxia
        description: White-matter and cerebellar system injury contribute to the core ataxic phenotype.
      - target: Spasticity
        description: Pyramidal tract dysfunction contributes to spastic clinical features.
      - target: Gait Ataxia
        description: Combined cerebellar and pyramidal-system injury produces gait impairment.
  - name: Mitochondrial Proteotoxic Stress Signaling
    description: >-
      In the SPAX5 subtype, biallelic AFG3L2 dysfunction causes mitochondrial
      proteotoxic stress and activates the OMA1-DELE1-HRI integrated stress
      response pathway.
    genes:
      - preferred_term: AFG3L2
        term:
          id: hgnc:315
          label: AFG3L2
    cell_types:
      - preferred_term: fibroblast
        term:
          id: CL:0000057
          label: fibroblast
      - preferred_term: Purkinje cell
        term:
          id: CL:0000121
          label: Purkinje cell
    evidence:
      - reference: DOI:10.1093/brain/awad340
        reference_title: Sustained OMA1-mediated integrated stress response is beneficial for spastic ataxia type 5
        supports: SUPPORT
        evidence_source: IN_VITRO
        snippet: >-
          In this work, we demonstrated that mitochondrial proteotoxicity in
          the absence/mutation of AFG3L2 activates the OMA1-DELE1-HRI pathway
          eliciting the integrated stress response.
        explanation: >-
          This directly supports a subtype-specific mitochondrial stress
          mechanism within the spastic-ataxia syndrome family.
    downstream:
      - target: Ataxia
        description: Purkinje neuron and cerebellar dysfunction produce ataxia.
      - target: Spasticity
        description: Mitochondrial neurodegeneration in SPAX5 includes spastic features.
phenotypes:
  - name: Ataxia
    description: >-
      Cerebellar ataxia is a defining feature of the syndrome.
    frequency: VERY_FREQUENT
    phenotype_term:
      preferred_term: ataxia
      term:
        id: HP:0001251
        label: Ataxia
    evidence:
      - reference: PMID:23033504
        reference_title: Reviewing the genetic causes of spastic-ataxias.
        supports: SUPPORT
        snippet: >-
          Although the combined presence of ataxia and pyramidal features has a
          long differential, the presence of a true spastic-ataxia as the
          predominant clinical syndrome has a rather limited differential
          diagnosis.
        explanation: >-
          This directly supports ataxia as one of the two defining syndrome
          elements.
  - name: Spasticity
    description: >-
      Pyramidal or spastic motor features are the other defining clinical
      component of the syndrome.
    frequency: VERY_FREQUENT
    phenotype_term:
      preferred_term: spasticity
      term:
        id: HP:0001257
        label: Spasticity
    evidence:
      - reference: PMID:23033504
        reference_title: Reviewing the genetic causes of spastic-ataxias.
        supports: SUPPORT
        snippet: >-
          Although the combined presence of ataxia and pyramidal features has a
          long differential, the presence of a true spastic-ataxia as the
          predominant clinical syndrome has a rather limited differential
          diagnosis.
        explanation: >-
          This directly supports pyramidal or spastic features as a defining
          syndrome component.
  - name: Gait Ataxia
    description: >-
      Gait impairment is a major functional manifestation of the combined
      ataxic and spastic syndrome.
    frequency: VERY_FREQUENT
    phenotype_term:
      preferred_term: gait ataxia
      term:
        id: HP:0002066
        label: Gait ataxia
    evidence:
      - reference: clinicaltrials:NCT06261424
        reference_title: >-
          IMPACT, a Supervised Rehabilitation Program for Spastic Ataxias: A
          Rater-blinded, Randomized Controlled Trial
        supports: PARTIAL
        snippet: >-
          Spastic ataxias are a group of diseases causing symptoms such as
          walking difficulties and balance impairments that lead to a high risk
          of falls.
        explanation: >-
          This directly supports gait and balance impairment as a major
          functional phenotype across spastic ataxias.
  - name: Dysarthria
    description: >-
      Dysarthria occurs in several spastic-ataxia subtypes as part of the
      cerebellar motor syndrome.
    phenotype_term:
      preferred_term: dysarthria
      term:
        id: HP:0001260
        label: Dysarthria
  - name: Dystonia
    subtype: SPAX5
    description: >-
      Dystonia is part of the reported SPAX5 clinical spectrum.
    frequency: OCCASIONAL
    phenotype_term:
      preferred_term: dystonia
      term:
        id: HP:0001332
        label: Dystonia
    evidence:
      - reference: DOI:10.1093/brain/awad340
        reference_title: Sustained OMA1-mediated integrated stress response is beneficial for spastic ataxia type 5
        supports: SUPPORT
        evidence_source: HUMAN_CLINICAL
        snippet: >-
          The clinical spectrum of SPAX5 includes childhood-onset cerebellar
          ataxia, spasticity, dystonia and myoclonic epilepsy.
        explanation: >-
          This directly supports dystonia in the SPAX5 subtype.
  - name: Myoclonic Epilepsy
    subtype: SPAX5
    description: >-
      Myoclonic epilepsy is part of the reported SPAX5 clinical spectrum.
    frequency: OCCASIONAL
    phenotype_term:
      preferred_term: myoclonic seizure
      term:
        id: HP:0032794
        label: Myoclonic seizure
    evidence:
      - reference: DOI:10.1093/brain/awad340
        reference_title: Sustained OMA1-mediated integrated stress response is beneficial for spastic ataxia type 5
        supports: SUPPORT
        evidence_source: HUMAN_CLINICAL
        snippet: >-
          The clinical spectrum of SPAX5 includes childhood-onset cerebellar
          ataxia, spasticity, dystonia and myoclonic epilepsy.
        explanation: >-
          This directly supports myoclonic epilepsy in the SPAX5 subtype.
genetic:
  - name: AFG3L2
    association: Causal biallelic variant
    gene_term:
      preferred_term: AFG3L2
      term:
        id: hgnc:315
        label: AFG3L2
    notes: >-
      Biallelic AFG3L2 variants define the SPAX5 subtype within the broader
      spastic-ataxia syndrome family.
    evidence:
      - reference: DOI:10.1093/brain/awad340
        reference_title: Sustained OMA1-mediated integrated stress response is beneficial for spastic ataxia type 5
        supports: SUPPORT
        snippet: >-
          Heterozygous AFG3L2 mutations cause spinocerebellar ataxia type 28
          (SCA28) or dominant optic atrophy type 12 (DOA12), while biallelic
          AFG3L2 mutations result in the rare and severe spastic ataxia type 5
          (SPAX5).
        explanation: >-
          This directly supports AFG3L2 as a causal gene within the syndrome
          spectrum.
  - name: SACS
    association: Causal biallelic variant
    gene_term:
      preferred_term: SACS
      term:
        id: hgnc:10519
        label: SACS
    notes: >-
      SACS variants cause autosomal recessive spastic ataxia of
      Charlevoix-Saguenay, a paradigmatic spastic-ataxia subtype.
    evidence:
      - reference: PMID:23033504
        reference_title: Reviewing the genetic causes of spastic-ataxias.
        supports: SUPPORT
        evidence_source: HUMAN_CLINICAL
        snippet: >-
          Autosomal recessive ataxia of Charlevoix-Saguenay, late-onset
          Friedreich ataxia, and hereditary spastic paraplegia type 7 are
          examples of genetic diseases with such a prominent spastic-ataxic
          syndrome as the clinical hallmark.
        explanation: >-
          This supports ARSACS, the SACS-related disease, as a genetic cause of
          the spastic-ataxia syndrome.
  - name: SPG7
    association: Causal biallelic variant
    gene_term:
      preferred_term: SPG7
      term:
        id: hgnc:11237
        label: SPG7
    notes: >-
      SPG7 variants cause hereditary spastic paraplegia type 7, a common
      genetic spastic-ataxia differential and subtype.
    evidence:
      - reference: PMID:23033504
        reference_title: Reviewing the genetic causes of spastic-ataxias.
        supports: SUPPORT
        evidence_source: HUMAN_CLINICAL
        snippet: >-
          Autosomal recessive ataxia of Charlevoix-Saguenay, late-onset
          Friedreich ataxia, and hereditary spastic paraplegia type 7 are
          examples of genetic diseases with such a prominent spastic-ataxic
          syndrome as the clinical hallmark.
        explanation: >-
          This directly supports hereditary spastic paraplegia type 7 as a
          genetic disease with a prominent spastic-ataxic syndrome.
environmental: []
treatments:
  - name: Supervised rehabilitation program
    description: >-
      Disease-specific rehabilitation is under active clinical evaluation for
      spastic ataxias.
    treatment_term:
      preferred_term: physical therapy
      term:
        id: MAXO:0000011
        label: physical therapy
    evidence:
      - reference: clinicaltrials:NCT06261424
        reference_title: >-
          IMPACT, a Supervised Rehabilitation Program for Spastic Ataxias: A
          Rater-blinded, Randomized Controlled Trial
        supports: SUPPORT
        snippet: >-
          The three objectives of this project are: 1) to determine the effect
          of a 12-week rehabilitation program on disease severity as compared
          with usual care for individuals with spastic ataxias;
        explanation: >-
          This directly supports rehabilitation as a disease-relevant
          intervention under formal study.
  - name: Aerobic exercise-based rehabilitation
    description: >-
      The IMPACT program is a structured exercise-based rehabilitation approach
      targeting gait, balance, and disease severity.
    treatment_term:
      preferred_term: aerobic exercise therapy
      term:
        id: MAXO:0000065
        label: aerobic exercise therapy
    evidence:
      - reference: clinicaltrials:NCT06261424
        reference_title: >-
          IMPACT, a Supervised Rehabilitation Program for Spastic Ataxias: A
          Rater-blinded, Randomized Controlled Trial
        supports: SUPPORT
        snippet: >-
          The team has developed the program to specifically target symptoms
          present in these patients and was previously pilot-tested.
        explanation: >-
          This supports structured exercise-oriented rehabilitation for the
          symptomatic treatment of spastic ataxias.
diagnosis:
  - name: Molecular genetic testing
    description: >-
      Molecular testing is necessary because spastic-ataxia syndromes are
      genetically heterogeneous.
    diagnosis_term:
      preferred_term: molecular genetic testing
      term:
        id: MAXO:0000533
        label: molecular genetic testing
    evidence:
      - reference: PMID:23033504
        reference_title: Reviewing the genetic causes of spastic-ataxias.
        supports: SUPPORT
        snippet: >-
          We review the various causes of spastic-ataxic syndromes with a focus
          on the genetic disorders, and provide a clinical framework, based on
          age at onset, mode of inheritance, and additional clinical features
          and neuroimaging signs, that could serve the diagnostic workup.
        explanation: >-
          This directly supports a genetics-driven diagnostic workup.
  - name: Brain MRI evaluation
    description: >-
      Diffusion MRI and brain white-matter assessment can distinguish subtype
      patterns and correlate with disease severity.
    diagnosis_term:
      preferred_term: magnetic resonance imaging procedure
      term:
        id: MAXO:0000424
        label: magnetic resonance imaging procedure
    evidence:
      - reference: DOI:10.1007/s00415-024-12505-y
        reference_title: >-
          An MRI evaluation of white matter involvement in paradigmatic forms of
          spastic ataxia: results from the multi-center PROSPAX study
        supports: SUPPORT
        snippet: >-
          Aim of this work was to thoroughly disentangle the degree of WM
          involvement in these conditions, evaluating both macrostructure and
          microstructure via the analysis of diffusion MRI (dMRI) data.
        explanation: >-
          This directly supports MRI evaluation as a useful diagnostic and
          disease-characterization tool.
differential_diagnoses: []
clinical_trials:
  - name: NCT06261424
    phase: NOT_APPLICABLE
    status: ACTIVE_NOT_RECRUITING
    description: >-
      A randomized controlled rehabilitation study testing a supervised
      12-week program for spastic ataxias.
    evidence:
      - reference: clinicaltrials:NCT06261424
        supports: SUPPORT
        snippet: >-
          The three objectives of this project are: 1) to determine the effect
          of a 12-week rehabilitation program on disease severity as compared
          with usual care for individuals with spastic ataxias;
        explanation: >-
          This directly supports a disease-relevant interventional clinical
          trial in spastic ataxias.
datasets: []
notes: >-
  Falcon deep research indicates that the exact label used in MONDO is not a
  standard disease name in the clinical literature. This page therefore models
  the MONDO concept as a heterogeneous spastic-ataxia syndrome anchored to the
  SPAX literature rather than forcing a single-gene interpretation.

📚

References & Deep Research

Deep Research

1

Falcon ▸

Disease Characteristics Research Template

Edison Scientific Literature 25 citations 2026-04-23T18:53:32.420779

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

Disease Name: Spasticity-Ataxia-Gait Anomalies Syndrome
MONDO ID: (if available)
Category: Neurological Disorder

Research Objectives

Please provide a comprehensive research report on Spasticity-Ataxia-Gait Anomalies Syndrome covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

What is the disease? Provide a concise overview.
What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
What are the common synonyms and alternative names?
Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
Risk Factors:

Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases
Genetic risk factors (causal variants, susceptibility loci, modifier genes)
Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
Protective Factors:

Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases
Genetic protective factors (protective variants, modifier alleles)
Environmental protective factors (diet, lifestyle, exposures that reduce risk)
Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene
Pathogenic Variants:
Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
Variant type/class (missense, frameshift, nonsense, splice-site, structural)
Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
Functional consequences (loss of function, gain of function, dominant negative)
Modifier Genes: Genes that modify disease severity or expression
Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth
Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases
Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

Search first: CDC databases, WHO, PubMed, NHANES
Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc
Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

Search first: Gene Ontology (GO), Reactome, KEGG, PubMed
Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold
Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA
Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

Search first: ImmPort, Immunome Database, IEDB, Gene Ontology
Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

Search first: PubMed, Gene Ontology, Reactome
Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

Search first: BRENDA, UniProt, KEGG, OMIM, PubMed
Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth
Molecular Profiling (if available):
Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
Advanced Technologies (if applicable):
Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

Organ Level:
Primary organs directly affected
Secondary organ involvement (complications, secondary effects)
Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT
Tissue and Cell Level:
Specific tissue types affected (epithelial, connective, muscle, nervous)
Specific cell populations targeted (with Cell Ontology terms)

Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB
Subcellular Level:
Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas
Localization:
Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

Onset:
Typical age of onset (congenital, pediatric, adult, geriatric)
Onset pattern (acute, subacute, chronic, insidious)

Search first: OMIM, Orphanet, HPO, PubMed
Progression:
Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
Progression rate (rapid, slow, variable)
Disease course pattern (episodic, relapsing-remitting, progressive, stable)
Disease duration (self-limited, chronic lifelong)

Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM
Patterns:
Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

Epidemiology:
Prevalence (cases per 100,000 at given time)
Incidence (new cases per 100,000 per year)

Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries
For Genetic Etiology:
Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
Population Demographics:
Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
Geographic distribution of specific variants
Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

Clinical Tests:
Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
Genetic Testing:

Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen
Overview of recommended genetic testing approach
Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
FISH > Search first: ClinVar, cytogenetics databases, PubMed
Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
Omics-Based Diagnostics (if applicable):
RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
Clinical Criteria:
Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
Screening:
Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

Survival and Mortality:
Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
Morbidity and Function:
Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
Disease Course:
Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
Prediction:
Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

Pharmacotherapy:
Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
Advanced Therapeutics:
Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
Surgical and Interventional:
Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
Supportive and Rehabilitative:
Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
Experimental:
Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
Treatment Outcomes:
Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
Treatment Strategy:
Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest MAXO (Medical Action Ontology) terms where applicable.

13. Prevention

Prevention Levels:
Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
Immunization: Vaccine strategies (if applicable)

Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database
Screening and Early Detection:
Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
Behavioral Interventions: Lifestyle modifications to reduce risk

Search first: CDC, WHO, behavioral intervention databases, Cochrane Library
Counseling: Genetic counseling (risk assessment, family planning guidance)

Search first: NSGC resources, ACMG guidelines, GeneReviews
Public Health:
Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
Prophylaxis: Preventive medications or procedures

Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

Taxonomy: Species affected (with NCBI Taxon identifiers)

Search first: NCBI Taxonomy
Breed: Specific breeds affected (with VBO identifiers if applicable)

Search first: VBO (Vertebrate Breed Ontology)
Gene: Orthologous genes in other species (with NCBI Gene IDs)

Search first: NCBI Gene
Natural Disease:
Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
Comparative Biology:
Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
Transmission (if applicable):
Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

Model Types:
Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
Genetic Models:
Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
Model Characteristics:
Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
Applications:
Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
Resources:
Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

Cite primary literature (PMID preferred) for all mechanistic and clinical claims
Prioritize recent reviews and landmark papers
Include direct quotes from abstracts where possible to support key statements
Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, MAXO, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Comprehensive Research Report: “Spasticity–Ataxia–Gait Anomalies Syndrome” (mapped to Spastic Ataxia / SPAX phenotype)

Executive summary

The string “Spasticity-Ataxia-Gait Anomalies Syndrome” is not a standardized disease name in the peer‑reviewed sources retrieved here. The most evidence-supported mapping is to the spastic ataxia (SPAX) phenotype—a clinical syndrome defined by cerebellar ataxia plus spasticity/pyramidal signs, which can arise from multiple gene-defined disorders (e.g., ARSACS/SACS, SPG7/SPG7, SPAX3/MARS2, SPAX4/MTPAP, SPAX5/AFG3L2) (bot2012reviewingthegenetic pages 4-5, scaravilli2024anmrievaluation pages 1-2).

Proposed standardized concept	Key synonyms/labels	Causal gene(s)	Inheritance	Key distinguishing features	Key citations with year/URL
Spastic ataxia (SPAX) phenotype	Spastic ataxia; SPAX; cerebellar ataxia with spasticity/pyramidal features	Phenotype-level umbrella; includes multiple genes/disorders	Mixed, depends on underlying disorder	Literature defines SPAX as a clinical phenotype characterized by cerebellar ataxia plus spasticity and other pyramidal features; useful highest-level mapping for the user label “Spasticity-Ataxia-Gait Anomalies Syndrome” (scaravilli2024anmrievaluation pages 1-2)	Scaravilli et al., 2024, J Neurol https://doi.org/10.1007/s00415-024-12505-y (scaravilli2024anmrievaluation pages 1-2)
ARSACS	Autosomal recessive spastic ataxia of Charlevoix-Saguenay; paradigmatic SPAX	SACS	Autosomal recessive	Early-onset spastic ataxia with severe white-matter involvement on diffusion MRI; in PROSPAX, ARSACS showed reduced global WM volume and altered microstructural metrics, with WM damage correlating with SARA scores; clinically often used as a core SPAX disorder and is the population targeted in rehabilitation trial NCT06261424 (scaravilli2024anmrievaluation pages 1-2, scaravilli2024anmrievaluation pages 2-4, NCT06261424 chunk 1)	Scaravilli et al., 2024, https://doi.org/10.1007/s00415-024-12505-y; Duchesne, NCT06261424, 2024, ClinicalTrials.gov (scaravilli2024anmrievaluation pages 1-2, scaravilli2024anmrievaluation pages 2-4, NCT06261424 chunk 1)
SPG7-associated spastic ataxia	SPG7; hereditary spastic paraplegia type 7; paradigmatic SPAX	SPG7	Usually autosomal recessive	Frequently presents with combined ataxia and spasticity; in PROSPAX, SPG7 had milder mean WM microstructural damage than ARSACS; NCT06261424 enrolls genetically confirmed SPG7 alongside ARSACS for supervised rehabilitation (scaravilli2024anmrievaluation pages 1-2, scaravilli2024anmrievaluation pages 2-4, NCT06261424 chunk 1)	Scaravilli et al., 2024, https://doi.org/10.1007/s00415-024-12505-y; Duchesne, NCT06261424, 2024, ClinicalTrials.gov (scaravilli2024anmrievaluation pages 1-2, scaravilli2024anmrievaluation pages 2-4, NCT06261424 chunk 1)
SPAX3	Autosomal recessive spastic ataxia 3; spastic ataxia with leukoencephalopathy; ARSAL	MARS2	Autosomal recessive	Described as spastic-ataxia with periventricular white-matter changes and cerebellar atrophy; age at onset reported from 2 to 59 years; strong match when gait abnormality co-occurs with leukodystrophy/leukoencephalopathy features (bot2012reviewingthegenetic pages 4-5)	de Bot et al., 2012, Neurology https://doi.org/10.1212/WNL.0b013e31826d5fb0 (bot2012reviewingthegenetic pages 4-5)
SPAX4	Autosomal recessive spastic ataxia 4	MTPAP	Autosomal recessive	Childhood-onset spastic paraparesis with cerebellar ataxia and dysarthria; additional features may include optic atrophy, delayed walking/speech, learning difficulties, emotional lability, and later areflexia—important when the user label implies developmental gait anomalies (bot2012reviewingthegenetic pages 4-5)	de Bot et al., 2012, Neurology https://doi.org/10.1212/WNL.0b013e31826d5fb0 (bot2012reviewingthegenetic pages 4-5)
SPAX5	Autosomal recessive spastic ataxia 5; AFG3L2-associated spastic-ataxia-neuropathy syndrome	AFG3L2	Autosomal recessive	Early-onset spastic-ataxic syndrome with neuropathy, cerebellar atrophy, oculomotor apraxia, dystonia, and mitochondrial features; mechanistically linked to AFG3L2 loss causing mitochondrial proteotoxicity, OMA1-DELE1-HRI integrated stress response activation, and potential therapeutic response to Sephin-1 in models (bot2012reviewingthegenetic pages 5-6, franchino2024sustainedoma1mediatedintegrated pages 1-2, franchino2024sustainedoma1mediatedintegrated pages 10-13)	de Bot et al., 2012, https://doi.org/10.1212/WNL.0b013e31826d5fb0; Franchino et al., 2024, Brain https://doi.org/10.1093/brain/awad340 (bot2012reviewingthegenetic pages 5-6, franchino2024sustainedoma1mediatedintegrated pages 1-2, franchino2024sustainedoma1mediatedintegrated pages 10-13)
SPAX1	Spastic ataxia 1	Locus on chromosome 12p13; gene not established in cited context	Autosomal dominant	Progressive spastic-ataxia reported in Newfoundland families, usually before age 20; useful historical SPAX mapping term, but less actionable clinically because gene was not established in the cited review (bot2012reviewingthegenetic pages 4-5)	de Bot et al., 2012, Neurology https://doi.org/10.1212/WNL.0b013e31826d5fb0 (bot2012reviewingthegenetic pages 4-5)
SPAX2	Spastic ataxia 2	Locus on chromosome 17p13; gene not established in cited context	Autosomal recessive	Family described with dysarthria and gait ataxia around age 14, later mild spasticity with amyotrophy/fasciculations; relevant if the user label is interpreted as a descriptive rather than gene-specific syndrome (bot2012reviewingthegenetic pages 4-5)	de Bot et al., 2012, Neurology https://doi.org/10.1212/WNL.0b013e31826d5fb0 (bot2012reviewingthegenetic pages 4-5)

Table: This table maps the nonstandard label “Spasticity-Ataxia-Gait Anomalies Syndrome” to standardized spastic-ataxia concepts used in the literature. It helps anchor the user’s query to phenotype-level and gene-defined entities that are actually described in current research and clinical studies.

1. Disease information

1.1 What is the disease?

Current understanding: “Spastic ataxia (SPAX)” is used in contemporary neurology as a phenotype-level umbrella: cerebellar ataxia with spasticity and other pyramidal features (scaravilli2024anmrievaluation pages 1-2). This umbrella includes multiple genetic conditions; two “paradigmatic” forms that are frequently studied are ARSACS and SPG7-associated spastic ataxia (scaravilli2024anmrievaluation pages 1-2, scaravilli2024anmrievaluation pages 2-4).

1.2 Key identifiers (OMIM/Orphanet/ICD/MeSH/MONDO)

OMIM (MIM) identifiers available from a classic spastic-ataxia review:
SPAX1: Spastic ataxia 1 (MIM %108600) (bot2012reviewingthegenetic pages 4-5)
SPAX2: Spastic ataxia 2 (MIM %611302) (bot2012reviewingthegenetic pages 4-5)
SPAX3/ARSAL: Autosomal recessive spastic ataxia 3 (MIM *609728) (bot2012reviewingthegenetic pages 4-5)
SPAX4: Autosomal recessive spastic ataxia 4 (MIM #613672) (bot2012reviewingthegenetic pages 4-5)
SPAX5: associated with AFG3L2; condition listed as MIM #614487; AFG3L2 gene MIM *604581 (bot2012reviewingthegenetic pages 5-6)
MONDO / Orphanet / ICD / MeSH: Not found in the retrieved evidence context for the exact user-provided label; mapping will depend on which gene-defined entity is intended.

1.3 Synonyms and alternative names (evidence-based)

“Spastic ataxia” / “SPAX” phenotype (scaravilli2024anmrievaluation pages 1-2)
“Autosomal recessive spastic ataxia of Charlevoix–Saguenay (ARSACS)” (scaravilli2024anmrievaluation pages 1-2, argenziano2024vestibularhypofunctionin pages 1-3)
“Spastic paraplegia type 7 (SPG7)” with a spastic-ataxic phenotype (scaravilli2024anmrievaluation pages 1-2)
“Spastic ataxia with leukoencephalopathy” / “ARSAL” for SPAX3 (bot2012reviewingthegenetic pages 4-5)

1.4 Evidence source type

The information synthesized here is primarily from: * Aggregated resources (systematic reviews/meta-analyses, mechanistic reviews, multicenter imaging studies) (scaravilli2024anmrievaluation pages 1-2, fereshtehnejad2023movementdisordersin pages 1-2, damiani2024pluripotentstemcells pages 14-15) * Primary observational genetics studies (families/cohorts) (azeem2024investigatingthegenetic pages 4-5) * Primary mechanistic disease-model work (patient fibroblasts and mouse/Purkinje neuron models) (franchino2024sustainedoma1mediatedintegrated pages 10-13) * ClinicalTrials.gov registry data for real-world trial implementation (NCT06261424 chunk 1)

2. Etiology

2.1 Disease causal factors

Genetic causes predominate in the SPAX phenotype. A reference spastic-ataxia genetic review enumerates multiple Mendelian entities; for several SPAX subtypes, causal genes are established: * SPAX3/ARSAL caused by MARS2 mutations; phenotype includes spastic-ataxia plus white matter changes and cerebellar atrophy, with onset ranging 2–59 years (bot2012reviewingthegenetic pages 4-5). * SPAX4 caused by homozygous MTPAP mutations; childhood-onset spastic paraparesis with cerebellar ataxia and additional features (e.g., optic atrophy, learning difficulties) (bot2012reviewingthegenetic pages 4-5). * SPAX5 associated with AFG3L2 mutations (bot2012reviewingthegenetic pages 5-6, franchino2024sustainedoma1mediatedintegrated pages 1-2). * ARSACS due to SACS variants (argenziano2024vestibularhypofunctionin pages 1-3). * SPG7-associated spastic ataxia due to biallelic SPG7 variants (scaravilli2024anmrievaluation pages 1-2).

2.2 Risk factors

Consanguinity/endogamy is a recurrent risk factor for autosomal recessive neurogenetic disorders in affected families, and is explicitly highlighted as common in a 2024 Pakistani-family study of HSP/HCA with spastic-ataxia overlap (azeem2024investigatingthegenetic pages 4-5).

2.3 Protective factors / gene–environment interactions

No protective factors or gene–environment interactions specific to “spasticity–ataxia–gait anomalies syndrome” were identified in the retrieved evidence.

3. Phenotypes

3.1 Core phenotype elements (SPAX concept)

Spasticity/pyramidal signs and cerebellar ataxia with gait disturbance are the defining clinical combination (scaravilli2024anmrievaluation pages 1-2).

3.2 Phenotype characteristics from recent/authoritative sources

ARSACS (SACS): described as early-onset ataxia characterized by cerebellar dysfunction, spasticity, and sensory-motor polyneuropathy (argenziano2024vestibularhypofunctionin pages 1-3). In a 2024 case report, exam showed “spastic-ataxic gait”, dysarthria, four-limb ataxia, and spastic hypertonia with lower-limb hyperreflexia (argenziano2024vestibularhypofunctionin pages 1-3).
SPG7 vs SPG11 (genotype–phenotype statistics, 2023 IPD meta-analysis): In HSP cases with movement disorders, SPG7 and SPG11 were the most frequent genotypes (31.2% and 23.8%) (fereshtehnejad2023movementdisordersin pages 1-2). Compared to SPG11, SPG7 cases had higher frequency of adult onset (82.9% vs 8.5%) and stronger association with ataxia (OR 12.6) and extraocular movement disturbances (OR 3.4) (fereshtehnejad2023movementdisordersin pages 1-2).
Disease course/variability: A 2024 ARSACS vestibular paper emphasizes variable expression in ARSACS (absence of some “defining” features may occur), underscoring that SPAX disorders may show incomplete/variable phenotypes (argenziano2024vestibularhypofunctionin pages 3-4).

3.3 Vestibular/oculomotor phenotypes (important for differential diagnosis)

ARSACS may show vestibular hypofunction, potentially mimicking CANVAS; in the reported ARSACS case, vHIT showed bilateral, symmetrical vestibulo-ocular reflex (VOR) impairment across semicircular canals and gaze-evoked/rebound nystagmus and saccadic pursuit abnormalities (argenziano2024vestibularhypofunctionin pages 1-3, argenziano2024vestibularhypofunctionin pages 3-4).

3.4 Suggested HPO terms (non-exhaustive; for knowledge base curation)

Spasticity (HP:0001257)
Hyperreflexia (HP:0001347)
Cerebellar ataxia (HP:0001251)
Gait ataxia (HP:0002066)
Spastic gait (HP:0002064)
Dysarthria (HP:0001260)
Peripheral neuropathy (HP:0009830)
Optic atrophy (HP:0000648) (noted in SPAX4 description) (bot2012reviewingthegenetic pages 4-5)
Cerebellar atrophy (HP:0001272) (noted across spastic ataxia entities; e.g., ARSACS/SPAX3) (bot2012reviewingthegenetic pages 4-5, scaravilli2024anmrievaluation pages 1-2)

(Where phenotype-level statements are evidence-based: see citations above.)

4. Genetic / molecular information

4.1 Causal genes highlighted in evidence

Key causal genes for spastic-ataxia entities in the retrieved sources include MARS2 (SPAX3/ARSAL), MTPAP (SPAX4), AFG3L2 (SPAX5), SACS (ARSACS), and SPG7 (SPG7 spastic ataxia phenotype) (bot2012reviewingthegenetic pages 4-5, bot2012reviewingthegenetic pages 5-6, scaravilli2024anmrievaluation pages 1-2, argenziano2024vestibularhypofunctionin pages 1-3).

4.2 Examples of pathogenic variants (recent cohort data)

A 2024 Pakistani-family WES study reported pathogenic variants segregating with HSP/HCA phenotypes (including spasticity/ataxia/gait phenotypes) in 5/8 families (62.5%), all consistent with autosomal recessive inheritance; onset ranged 1–14 years (mean 6.23, SD 3.96) (azeem2024investigatingthegenetic pages 4-5). Reported variants included: * SACS: c.2182C>T p.(Arg728); c.2229del p.(Phe743Leufs8) * FA2H: c.159_176del p.(Arg53_Ile58del) * ZFYVE26: c.1926_1941del p.(Tyr643Metfs2) * SPG11: c.2146C>T p.(Gln716) (azeem2024investigatingthegenetic pages 1-2, azeem2024investigatingthegenetic pages 4-5)

4.3 Functional consequences and pathways (mechanistic evidence)

SPAX5 (AFG3L2) mechanism (2024, Brain): SPAX5 results from biallelic AFG3L2 mutations; mechanistic work shows AFG3L2 loss/mutation leads to mitochondrial proteotoxic stress with activation of the stress-sensitive protease OMA1, engagement of an OMA1–DELE1–HRI axis, increased eIF2α phosphorylation, increased ATF4, and upregulation of ISR target genes (including Chop, Chac1, Ppp1r15a, Fgf21) in patient fibroblasts and Afg3l2−/− mouse cerebellum (franchino2024sustainedoma1mediatedintegrated pages 1-2, franchino2024sustainedoma1mediatedintegrated pages 10-13). Pharmacologic potentiation of the ISR with Sephin‑1 improved multiple cellular/neuron readouts and extended survival in Afg3l2−/− mice (franchino2024sustainedoma1mediatedintegrated pages 10-13).

SPG7 mitochondrial quality control (cell models): An iPSC-model review summarizes that SPG7/paraplegin is an inner-mitochondrial-membrane protease involved in mitochondrial protein quality control and biogenesis; patient-derived models show fragmented mitochondria, reduced respiration/ATP-linked oxygen consumption, increased ROS, and reduced neurite complexity (damiani2024pluripotentstemcells pages 14-15).

4.4 Suggested GO / pathway terms

Mitochondrial protein quality control / proteostasis (e.g., GO: mitochondrial protein processing)
Integrated stress response / eIF2α phosphorylation / ATF4 signaling
Mitochondrial fragmentation / OPA1 processing

(Evidence for these mechanisms in SPAX5 is direct; see citations above.) (franchino2024sustainedoma1mediatedintegrated pages 1-2, franchino2024sustainedoma1mediatedintegrated pages 10-13).

5. Environmental information

No specific environmental toxic, infectious, or lifestyle contributors were identified in the retrieved evidence for genetically defined spastic ataxias; the evidence base here is primarily neurogenetic.

6. Mechanism / pathophysiology (causal chains)

6.1 SPAX5 (AFG3L2) causal chain (primary mechanistic evidence)

Trigger: biallelic AFG3L2 loss-of-function (SPAX5) → mitochondrial proteotoxicity (accumulation of mitochondria-encoded proteins) → OMA1 overactivation → downstream signaling via DELE1–HRI → ISR activation (P-eIF2α/ATF4 and downstream targets) → neuronal dysfunction and cerebellar pathology; ISR potentiation can be protective in model systems (franchino2024sustainedoma1mediatedintegrated pages 1-2, franchino2024sustainedoma1mediatedintegrated pages 10-13).

6.2 ARSACS/SPAX white matter involvement (2024 PROSPAX dMRI)

In a multicenter diffusion-MRI study of paradigmatic SPAX forms, ARSACS demonstrated severe white matter involvement (reduced WM volume and broad microstructural metric changes), while SPG7 showed only mild mean microstructural damage vs controls (scaravilli2024anmrievaluation pages 1-2). In ARSACS, microstructural damage correlated with SARA (ataxia severity) (scaravilli2024anmrievaluation pages 1-2).

7. Anatomical structures affected

7.1 Organ/system level

Central nervous system: cerebellum and long motor pathways (pyramidal tracts) are implicated by the defining phenotype and neuroimaging/neuropathologic framing of HSP/SPAX conditions (scaravilli2024anmrievaluation pages 1-2, damiani2024pluripotentstemcells pages 14-15).

7.2 Tissue/cell level (suggested)

Purkinje neurons (cerebellar cortex) are directly studied as a vulnerable neuronal type in SPAX5 Afg3l2−/− models; Sephin‑1 improved survival/arborization ex vivo (franchino2024sustainedoma1mediatedintegrated pages 10-13).

Suggested CL term: Purkinje cell (CL:0000121).

7.3 Subcellular localization

Mitochondrial inner membrane: AFG3L2 is an inner mitochondrial membrane protease; AFG3L2 loss triggers OMA1/OPA1-related mitochondrial dynamics changes (franchino2024sustainedoma1mediatedintegrated pages 1-2, franchino2024sustainedoma1mediatedintegrated pages 10-13).

Suggested GO CC terms: mitochondrion (GO:0005739), mitochondrial inner membrane (GO:0005743).

8. Temporal development

8.1 Onset

SPAX3/ARSAL (MARS2): onset reported 2–59 years (bot2012reviewingthegenetic pages 4-5).
ARSACS: typically childhood/early-onset; case example onset at age 2 with slow progression (argenziano2024vestibularhypofunctionin pages 1-3).
WES family series (Pakistan): onset range 1–14 years (mean 6.23) across families with HSP/HCA phenotypes (azeem2024investigatingthegenetic pages 4-5).

8.2 Progression

Available evidence indicates progressive neurodegeneration for many spastic ataxia entities, but detailed stage models and longitudinal rates were not captured in the retrieved excerpts.

9. Inheritance and population

9.1 Inheritance

Many SPAX entities are autosomal recessive, including SPAX3 (MARS2), SPAX4 (MTPAP), SPAX5 (AFG3L2), ARSACS (SACS), and typical SPG7 spastic-ataxia presentations (bot2012reviewingthegenetic pages 4-5, bot2012reviewingthegenetic pages 5-6, NCT06261424 chunk 1).
SPAX1 is described as autosomal dominant locus in Newfoundland families (bot2012reviewingthegenetic pages 4-5).

9.2 Epidemiology

Disease-specific prevalence/incidence were not identified in the retrieved evidence for the nonstandard label. However, for HSP with movement disorders, an IPD meta-analysis aggregated 1,413 HSP cases across 192 manuscripts (fereshtehnejad2023movementdisordersin pages 1-2).

10. Diagnostics

10.1 Clinical and imaging

Diffusion MRI can quantify white matter macro/microstructural involvement in SPAX; PROSPAX used harmonized 3T dMRI and found marked WM abnormalities in ARSACS compared to SPG7 and controls (scaravilli2024anmrievaluation pages 1-2, scaravilli2024anmrievaluation pages 2-4).
Vestibular testing (vHIT) may uncover vestibular hypofunction in ARSACS and can complicate differential diagnosis with CANVAS (argenziano2024vestibularhypofunctionin pages 1-3, argenziano2024vestibularhypofunctionin pages 3-4).

10.2 Genetic testing (real-world implementation)

In a Pakistani cohort study, WES + segregation testing achieved a genetic diagnosis in 62.5% of families with hereditary spastic paraplegia / cerebellar ataxia phenotypes (azeem2024investigatingthegenetic pages 4-5).
In a specialized “CoQ10 deficiency” referral cohort of undiagnosed cerebellar ataxia, WES identified a definite genetic etiology in 8/16 (50%), including SPG7 among identified genes (monfrini2023wholeexomesequencingstudy pages 1-2).

11. Outcomes / prognosis

The retrieved evidence does not provide disease-specific survival or life expectancy for the umbrella SPAX phenotype. For SPAX5, a severe mouse model (Afg3l2−/−) shows early lethality that can be modestly improved with Sephin‑1, but extrapolation to human prognosis is not established (franchino2024sustainedoma1mediatedintegrated pages 10-13).

12. Treatment

12.1 Disease-modifying / mechanism-based (emerging)

SPAX5 (preclinical): ISR potentiation with Sephin‑1 improved growth and mitochondrial measures in SPAX5 fibroblasts and improved Purkinje neuron survival/arborization ex vivo; in vivo it improved mitochondrial ultrastructure/ATP and extended survival in Afg3l2−/− mice (franchino2024sustainedoma1mediatedintegrated pages 10-13). This is preclinical and not yet a standard human therapy.

12.2 Symptomatic and rehabilitative care (current applications)

Clinical trial implementation (2024–ongoing): ClinicalTrials.gov NCT06261424 (Laval University) is a multicenter, randomized, rater-blinded trial of a 12‑week supervised rehabilitation program (IMPACT) for genetically confirmed ARSACS and SPG7, enrolling ~84 participants, with primary endpoint SARA over a 64‑week timeframe; start date listed as 2024-02-01 (NCT06261424 chunk 1, NCT06261424 chunk 2). This represents a real-world implementation of structured rehabilitation for spastic ataxias.

12.3 Treatable mimics / targeted metabolic supplementation (selected patients)

CoQ10 supplementation rationale: In a 2023 Neurology Genetics study of patients referred for suspected CoQ10 deficiency, authors emphasize that diagnosing CoQ10 deficiency matters because patients may respond to CoQ10 supplementation, and they hypothesize a link between SPG7 mutations and secondary CoQ10 deficiency when CoQ10 was significantly decreased in SPG7 patient fibroblasts (monfrini2023wholeexomesequencingstudy pages 5-6, monfrini2023wholeexomesequencingstudy pages 1-2).

12.4 Suggested MAXO terms (examples)

Physical therapy / rehabilitation program
Genetic testing (WES/WGS)
Coenzyme Q10 supplementation
Deep brain stimulation (DBS) for selected movement-disorder phenotypes (not SPAX-specific, but reported as beneficial in VPS13D tremor and in selected HSP dystonia contexts; not fully extracted here)

13. Prevention

No primary prevention strategies were identified for Mendelian spastic ataxias beyond genetic counseling and family-based testing in appropriate settings.

14. Other species / natural disease

Not identified in the retrieved evidence.

15. Model organisms / experimental models

SPAX5: Afg3l2−/− mice, primary Purkinje neuron cultures, and patient-derived fibroblasts are used to study disease mechanisms and test therapeutic hypotheses (Sephin‑1) (franchino2024sustainedoma1mediatedintegrated pages 10-13).
SPG7/HSP: patient-derived iPSC neuronal models are described as platforms to reproduce mitochondrial phenotypes and to support drug discovery/repurposing (damiani2024pluripotentstemcells pages 14-15).

Expert opinions and analysis (authoritative, evidence-backed)

Phenotype-first framing: Contemporary imaging work explicitly treats “SPAX” as a phenotype: “presence of cerebellar ataxia along with spasticity and other pyramidal features,” supporting use of phenotype-level diagnostic reasoning before gene resolution (scaravilli2024anmrievaluation pages 1-2).
Diagnostic utility of genotype–phenotype patterns: The 2023 IPD meta-analysis concludes that genotype–phenotype differences (e.g., SPG7’s association with ataxia and adult onset vs SPG11’s association with neuropathy/cognitive dysfunction) are clinically useful and “can possibly facilitate diagnosis in resource-limited settings” (fereshtehnejad2023movementdisordersin pages 1-2).
Mechanism-informed therapy direction: The 2024 Brain SPAX5 study argues that pharmacologic tuning of the integrated stress response is a plausible future therapeutic strategy for mitochondrial-proteostasis-driven cerebellar disorders (franchino2024sustainedoma1mediatedintegrated pages 10-13).

Evidence gaps and limitations (for knowledge-base curation)

The user-provided disease name is not standardized in the evidence retrieved; the safest approach is to curate the entry as a phenotype umbrella (SPAX) with linked gene-defined child entities (ARSACS, SPG7, SPAX3/4/5, etc.).
MONDO/Orphanet/ICD/MeSH identifiers were not captured in the retrieved context; they should be added by direct lookup once the intended gene-defined entity is confirmed.
Many phenotype frequencies (percent affected) and long-term prognosis measures are gene- and cohort-dependent and were not available in the excerpts retrieved here.

References

(bot2012reviewingthegenetic pages 4-5): Susanne T. de Bot, Michel A.A.P. Willemsen, Sascha Vermeer, Hubertus P.H. Kremer, and Bart P.C. van de Warrenburg. Reviewing the genetic causes of spastic-ataxias. Neurology, 79:1507-1514, Oct 2012. URL: https://doi.org/10.1212/wnl.0b013e31826d5fb0, doi:10.1212/wnl.0b013e31826d5fb0. This article has 90 citations and is from a highest quality peer-reviewed journal.
(scaravilli2024anmrievaluation pages 1-2): Alessandra Scaravilli, Ilaria Gabusi, Gaia Mari, Matteo Battocchio, Sara Bosticardo, Simona Schiavi, Benjamin Bender, Christoph Kessler, Bernard Brais, Roberta La Piana, Bart P. van de Warrenburg, Mirco Cosottini, Dagmar Timmann, Alessandro Daducci, Rebecca Schüle, Matthis Synofzik, Filippo Maria Santorelli, and Sirio Cocozza. An mri evaluation of white matter involvement in paradigmatic forms of spastic ataxia: results from the multi-center prospax study. Journal of Neurology, 271:5468-5477, Jun 2024. URL: https://doi.org/10.1007/s00415-024-12505-y, doi:10.1007/s00415-024-12505-y. This article has 4 citations and is from a domain leading peer-reviewed journal.
(scaravilli2024anmrievaluation pages 2-4): Alessandra Scaravilli, Ilaria Gabusi, Gaia Mari, Matteo Battocchio, Sara Bosticardo, Simona Schiavi, Benjamin Bender, Christoph Kessler, Bernard Brais, Roberta La Piana, Bart P. van de Warrenburg, Mirco Cosottini, Dagmar Timmann, Alessandro Daducci, Rebecca Schüle, Matthis Synofzik, Filippo Maria Santorelli, and Sirio Cocozza. An mri evaluation of white matter involvement in paradigmatic forms of spastic ataxia: results from the multi-center prospax study. Journal of Neurology, 271:5468-5477, Jun 2024. URL: https://doi.org/10.1007/s00415-024-12505-y, doi:10.1007/s00415-024-12505-y. This article has 4 citations and is from a domain leading peer-reviewed journal.
(NCT06261424 chunk 1): Elise Duchesne. Effects of a Supervised Rehabilitation Program on Disease Severity in Spastic Ataxias. Laval University. 2024. ClinicalTrials.gov Identifier: NCT06261424
(bot2012reviewingthegenetic pages 5-6): Susanne T. de Bot, Michel A.A.P. Willemsen, Sascha Vermeer, Hubertus P.H. Kremer, and Bart P.C. van de Warrenburg. Reviewing the genetic causes of spastic-ataxias. Neurology, 79:1507-1514, Oct 2012. URL: https://doi.org/10.1212/wnl.0b013e31826d5fb0, doi:10.1212/wnl.0b013e31826d5fb0. This article has 90 citations and is from a highest quality peer-reviewed journal.
(franchino2024sustainedoma1mediatedintegrated pages 1-2): Camilla Aurora Franchino, Martina Brughera, Valentina Baderna, Daniele De Ritis, Alessandra Rocco, Sara Seneca, Luc Regal, Paola Podini, Maurizio D’Antonio, Camilo Toro, Angelo Quattrini, Emmanuel Scalais, and Francesca Maltecca. Sustained oma1-mediated integrated stress response is beneficial for spastic ataxia type 5. Brain, 147:1043-1056, Oct 2024. URL: https://doi.org/10.1093/brain/awad340, doi:10.1093/brain/awad340. This article has 17 citations and is from a highest quality peer-reviewed journal.
(franchino2024sustainedoma1mediatedintegrated pages 10-13): Camilla Aurora Franchino, Martina Brughera, Valentina Baderna, Daniele De Ritis, Alessandra Rocco, Sara Seneca, Luc Regal, Paola Podini, Maurizio D’Antonio, Camilo Toro, Angelo Quattrini, Emmanuel Scalais, and Francesca Maltecca. Sustained oma1-mediated integrated stress response is beneficial for spastic ataxia type 5. Brain, 147:1043-1056, Oct 2024. URL: https://doi.org/10.1093/brain/awad340, doi:10.1093/brain/awad340. This article has 17 citations and is from a highest quality peer-reviewed journal.
(argenziano2024vestibularhypofunctionin pages 1-3): Giacomo Argenziano, Francesco Cavallieri, Andrea Castellucci, Valentina Fioravanti, Giulia Di Rauso, Annalisa Gessani, Isabella Campanini, Andrea Merlo, Manuela Napoli, Sara Grisanti, Jessica Rossi, Giulia Toschi, Chiara Zini, Angelo Ghidini, and Franco Valzania. Vestibular hypofunction in arsacs syndrome: a possible pitfall in the differential diagnosis of recessive cerebellar and afferent ataxias. Neurology. Clinical practice, 14 1:e200239, Feb 2024. URL: https://doi.org/10.1212/cpj.0000000000200239, doi:10.1212/cpj.0000000000200239. This article has 1 citations.
(fereshtehnejad2023movementdisordersin pages 1-2): Seyed-Mohammad Fereshtehnejad, Philip A. Saleh, Lais M. Oliveira, Neha Patel, Suvorit Bhowmick, Gerard Saranza, and Lorraine V. Kalia. Movement disorders in hereditary spastic paraplegia (hsp): a systematic review and individual participant data meta-analysis. Neurological Sciences, 44:947-959, Nov 2023. URL: https://doi.org/10.1007/s10072-022-06516-8, doi:10.1007/s10072-022-06516-8. This article has 17 citations and is from a peer-reviewed journal.
(damiani2024pluripotentstemcells pages 14-15): Devid Damiani, Matteo Baggiani, Stefania Della Vecchia, Valentina Naef, and Filippo Maria Santorelli. Pluripotent stem cells as a preclinical cellular model for studying hereditary spastic paraplegias. International Journal of Molecular Sciences, 25:2615, Feb 2024. URL: https://doi.org/10.3390/ijms25052615, doi:10.3390/ijms25052615. This article has 10 citations.
(azeem2024investigatingthegenetic pages 4-5): Arfa Azeem, Asif Naveed Ahmed, Niamat Khan, Nikol Voutsina, Irfan Ullah, Nishanka Ubeyratna, Muhammad Yasin, Emma L. Baple, Andrew H. Crosby, Lettie E. Rawlins, and Shamim Saleha. Investigating the genetic basis of hereditary spastic paraplegia and cerebellar ataxia in pakistani families. BMC Neurology, Sep 2024. URL: https://doi.org/10.1186/s12883-024-03855-1, doi:10.1186/s12883-024-03855-1. This article has 3 citations and is from a peer-reviewed journal.
(argenziano2024vestibularhypofunctionin pages 3-4): Giacomo Argenziano, Francesco Cavallieri, Andrea Castellucci, Valentina Fioravanti, Giulia Di Rauso, Annalisa Gessani, Isabella Campanini, Andrea Merlo, Manuela Napoli, Sara Grisanti, Jessica Rossi, Giulia Toschi, Chiara Zini, Angelo Ghidini, and Franco Valzania. Vestibular hypofunction in arsacs syndrome: a possible pitfall in the differential diagnosis of recessive cerebellar and afferent ataxias. Neurology. Clinical practice, 14 1:e200239, Feb 2024. URL: https://doi.org/10.1212/cpj.0000000000200239, doi:10.1212/cpj.0000000000200239. This article has 1 citations.
(azeem2024investigatingthegenetic pages 1-2): Arfa Azeem, Asif Naveed Ahmed, Niamat Khan, Nikol Voutsina, Irfan Ullah, Nishanka Ubeyratna, Muhammad Yasin, Emma L. Baple, Andrew H. Crosby, Lettie E. Rawlins, and Shamim Saleha. Investigating the genetic basis of hereditary spastic paraplegia and cerebellar ataxia in pakistani families. BMC Neurology, Sep 2024. URL: https://doi.org/10.1186/s12883-024-03855-1, doi:10.1186/s12883-024-03855-1. This article has 3 citations and is from a peer-reviewed journal.
(monfrini2023wholeexomesequencingstudy pages 1-2): Edoardo Monfrini, Alba Pesini, Fabio Biella, Claudia F.R. Sobreira, Valentina Emmanuele, Gloria Brescia, Luis Carlos Lopez, Saba Tadesse, Michio Hirano, Giacomo P. Comi, Catarina Maria Quinzii, and Alessio Di Fonzo. Whole-exome sequencing study of fibroblasts derived from patients with cerebellar ataxia referred to investigate coq10 deficiency. Neurology Genetics, Apr 2023. URL: https://doi.org/10.1212/nxg.0000000000200058, doi:10.1212/nxg.0000000000200058. This article has 3 citations.
(NCT06261424 chunk 2): Elise Duchesne. Effects of a Supervised Rehabilitation Program on Disease Severity in Spastic Ataxias. Laval University. 2024. ClinicalTrials.gov Identifier: NCT06261424
(monfrini2023wholeexomesequencingstudy pages 5-6): Edoardo Monfrini, Alba Pesini, Fabio Biella, Claudia F.R. Sobreira, Valentina Emmanuele, Gloria Brescia, Luis Carlos Lopez, Saba Tadesse, Michio Hirano, Giacomo P. Comi, Catarina Maria Quinzii, and Alessio Di Fonzo. Whole-exome sequencing study of fibroblasts derived from patients with cerebellar ataxia referred to investigate coq10 deficiency. Neurology Genetics, Apr 2023. URL: https://doi.org/10.1212/nxg.0000000000200058, doi:10.1212/nxg.0000000000200058. This article has 3 citations.

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Pathophysiology

Pathograph

Phenotypes

Genetic Associations

Treatments

Clinical Trials

Source YAML

References & Deep Research

Deep Research

Disease Characteristics Research Template

Target Disease

Research Objectives

1. Disease Information

2. Etiology

3. Phenotypes

4. Genetic/Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome/Prognosis

12. Treatment

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Citation Requirements

Output Format

Comprehensive Research Report: “Spasticity–Ataxia–Gait Anomalies Syndrome” (mapped to Spastic Ataxia / SPAX phenotype)

Executive summary

1. Disease information

1.1 What is the disease?

1.2 Key identifiers (OMIM/Orphanet/ICD/MeSH/MONDO)

1.3 Synonyms and alternative names (evidence-based)

1.4 Evidence source type

2. Etiology

2.1 Disease causal factors

2.2 Risk factors

2.3 Protective factors / gene–environment interactions

3. Phenotypes

3.1 Core phenotype elements (SPAX concept)

3.2 Phenotype characteristics from recent/authoritative sources

3.3 Vestibular/oculomotor phenotypes (important for differential diagnosis)

3.4 Suggested HPO terms (non-exhaustive; for knowledge base curation)

4. Genetic / molecular information

4.1 Causal genes highlighted in evidence

4.2 Examples of pathogenic variants (recent cohort data)

4.3 Functional consequences and pathways (mechanistic evidence)

4.4 Suggested GO / pathway terms

5. Environmental information

6. Mechanism / pathophysiology (causal chains)

6.1 SPAX5 (AFG3L2) causal chain (primary mechanistic evidence)

6.2 ARSACS/SPAX white matter involvement (2024 PROSPAX dMRI)

7. Anatomical structures affected

7.1 Organ/system level

7.2 Tissue/cell level (suggested)

7.3 Subcellular localization

8. Temporal development

8.1 Onset

8.2 Progression

9. Inheritance and population

9.1 Inheritance

9.2 Epidemiology

10. Diagnostics

10.1 Clinical and imaging

10.2 Genetic testing (real-world implementation)

11. Outcomes / prognosis

12. Treatment

12.1 Disease-modifying / mechanism-based (emerging)

12.2 Symptomatic and rehabilitative care (current applications)

12.3 Treatable mimics / targeted metabolic supplementation (selected patients)

12.4 Suggested MAXO terms (examples)

13. Prevention

14. Other species / natural disease

15. Model organisms / experimental models

Expert opinions and analysis (authoritative, evidence-backed)