Leigh Syndrome

Mendelian MONDO:0009723 Pathograph 17 hereditary disease mitochondrial disease

Leigh syndrome (subacute necrotizing encephalomyelopathy) is a genetically heterogeneous mitochondrial disorder of cellular energy metabolism. It is the most common pediatric presentation of mitochondrial disease and is defined neuropathologically by bilateral, symmetric necrotic lesions of the basal ganglia, thalamus, and brainstem. The shared biochemical defect is impaired oxidative phosphorylation/ATP production, most frequently from isolated complex I deficiency, complex IV (cytochrome c oxidase) deficiency, MT-ATP6 (complex V) dysfunction, or pyruvate dehydrogenase complex deficiency. More than 75 causative genes are known across the mitochondrial and nuclear genomes. Onset is typically in infancy or early childhood with psychomotor regression, hypotonia, brainstem and basal-ganglia dysfunction, and lactic acidosis.

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7
Pathophys.
14
Phenotypes
17
Pathograph
6
Genes
2
Treatments
4
Subtypes
1
Trials
2
References
1
Deep Research
◆

Subtypes

4
Maternally-inherited Leigh syndrome (MT-ATP6) MONDO:0016814
Maternally inherited Leigh syndrome caused by pathogenic mitochondrial DNA variants, most commonly MT-ATP6 nucleotide 8993 substitutions, with severity dependent on heteroplasmy.
French-Canadian (Saguenay-Lac-Saint-Jean) type MONDO:0009069
Congenital lactic acidosis of the Saguenay-Lac-Saint-Jean region caused by biallelic LRPPRC variants, presenting as a complex IV (cytochrome c oxidase)-deficient Leigh syndrome.
Leigh syndrome with cardiomyopathy MONDO:0019083
Leigh syndrome presentations with prominent hypertrophic cardiomyopathy, seen with several nuclear assembly-factor and mtDNA defects.
Adult subacute necrotizing encephalomyelopathy MONDO:0008069
Rare adult-onset form of subacute necrotizing encephalomyelopathy with the characteristic symmetric brainstem and basal-ganglia lesions.
⚙

Pathophysiology

7
Oxidative phosphorylation deficiency
The unifying biochemical lesion in Leigh syndrome is impaired mitochondrial oxidative phosphorylation, reducing ATP synthesis in tissues with high energy demand. Causative defects converge on the respiratory chain complexes (most often complex I), complex IV, ATP synthase (complex V), or upstream pyruvate oxidation.
oxidative phosphorylation link ↓ DECREASED proton motive force-driven mitochondrial ATP synthesis link ↓ DECREASED
Downstream
Lactic acidosis Impaired pyruvate oxidation and respiratory-chain flux shift metabolism toward anaerobic glycolysis, raising lactate.
Energy-dependent neuronal vulnerability Energy failure preferentially injures metabolically active neurons of the basal ganglia and brainstem.
Show evidence (2 references)
PMID:26506407 SUPPORT Human Clinical
"Leigh syndrome is the most common pediatric presentation of mitochondrial disease."
This review establishes Leigh syndrome as the prototypical pediatric mitochondrial (oxidative phosphorylation) disorder.
PMID:26506407 SUPPORT Human Clinical
"This neurodegenerative disorder is genetically heterogeneous, and to date pathogenic mutations in >75 genes have been identified, encoded by 2 genomes (mitochondrial and nuclear)."
Supports the convergence of >75 mitochondrial and nuclear genes on a shared defect of mitochondrial energy generation.
Complex I deficiency
Isolated deficiency of NADH:ubiquinone oxidoreductase (respiratory chain complex I) is the single most common biochemical cause of Leigh syndrome, arising from mtDNA MT-ND subunit variants or nuclear NDUFS/NDUFV/NDUFA subunit and assembly-factor defects.
NDUFS4 link NDUFV1 link MT-ND5 link
mitochondrial electron transport, NADH to ubiquinone link ↓ DECREASED
NADH dehydrogenase (ubiquinone) activity link ↓ DECREASED
NADH dehydrogenase complex link
Downstream
Oxidative phosphorylation deficiency Reduced complex I activity lowers respiratory-chain flux and ATP output.
Show evidence (2 references)
PMID:38177503 SUPPORT Model Organism
"Complex I mutations cause neuromuscular, mitochondrial diseases, such as Leigh Syndrome, but their molecular-level consequences remain poorly understood."
Establishes complex I (NADH:ubiquinone oxidoreductase) deficiency as a cause of Leigh syndrome; the ndufs4-/- mouse is the canonical complex I-linked disease model.
PMID:38177503 SUPPORT Model Organism
"Cryo-EM analyses of the complex I from ndufs4-/- mouse hearts revealed a loose association of the NADH-dehydrogenase module"
Structural data show that loss of subunit NDUFS4 destabilizes the NADH-dehydrogenase module of complex I, the molecular basis of complex I-deficient Leigh syndrome.
Complex IV (cytochrome c oxidase) deficiency
Cytochrome c oxidase deficiency, classically from SURF1 assembly-factor loss or LRPPRC (French-Canadian Leigh) defects, is a major cause of Leigh syndrome with reduced terminal electron transfer to oxygen.
SURF1 link LRPPRC link
mitochondrial respiratory chain complex IV assembly link ↓ DECREASED
cytochrome-c oxidase activity link ↓ DECREASED
Downstream
Oxidative phosphorylation deficiency Loss of cytochrome c oxidase blocks terminal electron transport.
Show evidence (2 references)
PMID:9837813 SUPPORT Human Clinical
"Sequence analysis of SURF-1 revealed mutations in numerous DNA samples from LD(COX-) patients, indicating that this gene is responsible for the major complementation group in this important mitochondrial disorder."
Identifies SURF1 (a cytochrome c oxidase assembly factor) as the major cause of Leigh disease with cytochrome c oxidase (complex IV) deficiency.
PMID:12529507 SUPPORT Human Clinical
"Resequencing identified two mutations on two independent haplotypes, providing definitive genetic proof that LRPPRC indeed causes LSFC."
Establishes LRPPRC as the cause of Leigh syndrome, French-Canadian type, a complex IV (cytochrome c oxidase) deficiency.
MT-ATP6 ATP synthase (complex V) dysfunction
Pathogenic MT-ATP6 variants, especially nucleotide 8993 substitutions, impair the proton-translocating sector of ATP synthase and produce maternally inherited Leigh syndrome when heteroplasmy is high.
MT-ATP6 link
proton-transporting ATP synthase activity, rotational mechanism link ↓ DECREASED
proton-transporting ATP synthase complex link
Downstream
Oxidative phosphorylation deficiency Defective ATP synthase coupling decreases ATP generation.
Show evidence (1 reference)
PMID:16525806 SUPPORT Human Clinical
"The 8993 T>G mutation in mitochondrial DNA has been associated with variable syndromes of differing severity ranging from maternally inherited Leigh's syndrome (MILS) to neuropathy, ataxia, retinitis pigmentosa (NARP), depending on the mutation loads in affected patients."
Supports the canonical MT-ATP6 nucleotide 8993 variant as a cause of maternally inherited Leigh syndrome, with severity governed by heteroplasmy (mutation load).
Pyruvate dehydrogenase complex deficiency
X-linked PDHA1 and related pyruvate dehydrogenase complex defects block conversion of pyruvate to acetyl-CoA, depriving the TCA cycle of substrate and producing a Leigh phenotype with prominent lactic acidosis.
PDHA1 link
pyruvate metabolic process link ↓ DECREASED
Downstream
Lactic acidosis Blocked pyruvate oxidation diverts pyruvate to lactate.
Oxidative phosphorylation deficiency Reduced acetyl-CoA limits TCA-cycle reducing equivalents for the respiratory chain.
Show evidence (1 reference)
PMID:33661577 SUPPORT Human Clinical
"A PDHA1 mutation (NM_000284.4:c.1167_1170del) was identified as the underlying cause."
A case in which an X-linked PDHA1 (pyruvate dehydrogenase E1-alpha) mutation underlies a Leigh syndrome presentation.
Lactic acidosis
Impaired aerobic ATP production shifts metabolism to anaerobic glycolysis, elevating lactate in blood and cerebrospinal fluid.
Downstream
Energy-dependent neuronal vulnerability Systemic and CNS acidosis compounds energetic stress on vulnerable neurons.
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Decompensation (often with elevated lactate levels in blood and/or cerebrospinal fluid) is typically associated with developmental delay and/or regression."
GeneReviews documents elevated blood and CSF lactate during metabolic decompensation, the biochemical signature of impaired aerobic ATP production.
Energy-dependent neuronal vulnerability
Chronic energy deficiency injures metabolically demanding neurons and glia, producing the characteristic bilateral symmetric necrotic lesions, capillary proliferation, and gliosis of the basal ganglia, thalamus, and brainstem that define Leigh syndrome neuropathology.
neuron link astrocyte link
basal ganglion link brainstem link
Downstream
Developmental regression Progressive lesion accumulation drives loss of acquired milestones.
Show evidence (1 reference)
PMID:16525806 SUPPORT Human Clinical
"Post-mortem studies of the brain in one affected member clinically presenting with a neurological disorder intermediate between adult Leigh's syndrome and NARP showed symmetrical lesions of the basal ganglia and brainstem closely resembling those usually described in typical Leigh's syndrome."
Post-mortem neuropathology documents the bilateral symmetric basal-ganglia and brainstem lesions that define Leigh syndrome and reflect regional energy-dependent neuronal vulnerability.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Leigh Syndrome Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
●

Phenotypes

14
Cardiovascular 1
Cardiomyopathy Cardiomyopathy (HP:0001638)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Extraneurologic manifestations may include poor weight gain, cardiomyopathy, and conduction defects."
GeneReviews lists cardiomyopathy among the extraneurologic manifestations of the Leigh syndrome spectrum; cardiac failure is a leading cause of death.
Digestive 1
Feeding difficulties Feeding difficulties (HP:0011968)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Brain stem dysfunction may manifest with respiratory symptoms, swallowing difficulties, ophthalmoparesis, and abnormalities in thermoregulation."
GeneReviews attributes swallowing (feeding) difficulties to brainstem dysfunction in the Leigh syndrome spectrum.
Eye 1
Nystagmus Nystagmus (HP:0000639)
Metabolism 1
Lactic acidosis Lactic acidosis (HP:0003128)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Decompensation (often with elevated lactate levels in blood and/or cerebrospinal fluid) is typically associated with developmental delay and/or regression."
GeneReviews documents elevated blood and CSF lactate as a hallmark of metabolic decompensation in the Leigh syndrome spectrum.
Musculoskeletal 2
Hypotonia Hypotonia (HP:0001252)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Neurologic features include hypotonia, spasticity, seizures, movement disorders, cerebellar ataxia, and peripheral neuropathy."
GeneReviews lists hypotonia among the core neurologic features of the Leigh syndrome spectrum.
Spasticity Spasticity (HP:0001257)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Neurologic features include hypotonia, spasticity, seizures, movement disorders, cerebellar ataxia, and peripheral neuropathy."
GeneReviews lists spasticity among the core neurologic features of the Leigh syndrome spectrum.
Nervous System 6
Developmental regression Developmental regression (HP:0002376)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Decompensation (often with elevated lactate levels in blood and/or cerebrospinal fluid) is typically associated with developmental delay and/or regression."
GeneReviews documents developmental delay and regression as a core feature of the Leigh syndrome spectrum.
Dystonia Dystonia (HP:0001332)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Neurologic features include hypotonia, spasticity, seizures, movement disorders, cerebellar ataxia, and peripheral neuropathy."
GeneReviews lists movement disorders among core neurologic features; dystonia is the characteristic basal-ganglia movement disorder of Leigh syndrome.
Ataxia Ataxia (HP:0001251)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Neurologic features include hypotonia, spasticity, seizures, movement disorders, cerebellar ataxia, and peripheral neuropathy."
GeneReviews lists cerebellar ataxia among the core neurologic features of the Leigh syndrome spectrum.
Peripheral neuropathy Peripheral neuropathy (HP:0009830)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Neurologic features include hypotonia, spasticity, seizures, movement disorders, cerebellar ataxia, and peripheral neuropathy."
GeneReviews lists peripheral neuropathy among the core neurologic features of the Leigh syndrome spectrum.
Seizures Seizure (HP:0001250)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Neurologic features include hypotonia, spasticity, seizures, movement disorders, cerebellar ataxia, and peripheral neuropathy."
GeneReviews lists seizures among the core neurologic features of the Leigh syndrome spectrum.
Abnormal basal ganglia morphology Abnormal basal ganglia morphology (HP:0002134)
Show evidence (1 reference)
PMID:16525806 SUPPORT Human Clinical
"Post-mortem studies of the brain in one affected member clinically presenting with a neurological disorder intermediate between adult Leigh's syndrome and NARP showed symmetrical lesions of the basal ganglia and brainstem closely resembling those usually described in typical Leigh's syndrome."
Neuropathology documents the symmetric basal-ganglia lesions that are the diagnostic hallmark of Leigh syndrome.
Respiratory 1
Respiratory abnormalities Respiratory distress (HP:0002098)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Brain stem dysfunction may manifest with respiratory symptoms, swallowing difficulties, ophthalmoparesis, and abnormalities in thermoregulation."
GeneReviews attributes respiratory symptoms to brainstem dysfunction; respiratory failure is a leading cause of death in the Leigh syndrome spectrum.
Other 1
Ophthalmoplegia Ophthalmoplegia (HP:0000602)
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Brain stem dysfunction may manifest with respiratory symptoms, swallowing difficulties, ophthalmoparesis, and abnormalities in thermoregulation."
GeneReviews attributes ophthalmoparesis (ophthalmoplegia) to brainstem dysfunction in the Leigh syndrome spectrum.
🧬

Genetic Associations

6
NDUFS4 (Biallelic NDUFS4 loss-of-function variants cause complex I-deficient Leigh syndrome.)
Autosomal recessive inheritance
Show evidence (1 reference)
PMID:38177503 SUPPORT Model Organism
"we use a popular complex I-linked mitochondrial disease model, the ndufs4-/- mouse, to define the structural, biochemical, and functional consequences of the absence of subunit NDUFS4."
The ndufs4-/- mouse is an established model of complex I-deficient Leigh syndrome, supporting NDUFS4 loss as a cause of the disorder.
NDUFV1 (Biallelic variants in the nuclear-encoded complex I core subunit gene NDUFV1 cause complex I-deficient Leigh syndrome.)
Autosomal recessive inheritance
Show evidence (1 reference)
PMID:26506407 PARTIAL Human Clinical
"This neurodegenerative disorder is genetically heterogeneous, and to date pathogenic mutations in >75 genes have been identified, encoded by 2 genomes (mitochondrial and nuclear)."
NDUFV1 is one of the nuclear-encoded complex I subunit genes among the >75 monogenic causes of Leigh syndrome catalogued in this review; the review supports nuclear complex I subunit genes as a cause but does not name NDUFV1 individually, hence PARTIAL.
SURF1 (Biallelic SURF1 variants impair cytochrome c oxidase assembly and are a common cause of complex IV-deficient Leigh syndrome.)
Autosomal recessive inheritance
Show evidence (1 reference)
PMID:9837813 SUPPORT Human Clinical
"Sequence analysis of SURF-1 revealed mutations in numerous DNA samples from LD(COX-) patients, indicating that this gene is responsible for the major complementation group in this important mitochondrial disorder."
Identifies SURF1 as the major causative gene for cytochrome c oxidase-deficient Leigh disease.
LRPPRC (Biallelic LRPPRC variants cause the French-Canadian (Saguenay-Lac-Saint-Jean) type of cytochrome c oxidase (complex IV)-deficient Leigh syndrome.)
Autosomal recessive inheritance
Show evidence (1 reference)
PMID:12529507 SUPPORT Human Clinical
"Resequencing identified two mutations on two independent haplotypes, providing definitive genetic proof that LRPPRC indeed causes LSFC."
Establishes biallelic LRPPRC variants as the cause of Leigh syndrome, French-Canadian type (LSFC), a complex IV (cytochrome c oxidase) deficiency.
MT-ATP6 (Maternally inherited MT-ATP6 nucleotide 8993 variants cause maternally inherited Leigh syndrome with heteroplasmy-dependent severity.)
Mitochondrial inheritance
Show evidence (1 reference)
PMID:16525806 SUPPORT Human Clinical
"The 8993 T>G mutation in mitochondrial DNA has been associated with variable syndromes of differing severity ranging from maternally inherited Leigh's syndrome (MILS) to neuropathy, ataxia, retinitis pigmentosa (NARP), depending on the mutation loads in affected patients."
Supports MT-ATP6 m.8993T>G as a maternally inherited cause of Leigh syndrome (MILS).
PDHA1 (X-linked PDHA1 variants cause pyruvate dehydrogenase deficiency presenting as Leigh syndrome.)
X-linked inheritance
Show evidence (1 reference)
PMID:33661577 SUPPORT Human Clinical
"Leigh syndrome, the most common mitochondrial syndrome in pediatrics, has diverse clinical manifestations and is genetically heterogeneous."
Case report establishing an X-linked PDHA1 frameshift mutation as the cause of a Leigh syndrome presentation.
💊

Treatments

2
Supportive mitochondrial disease management
Action: supportive care MAXO:0000950
No disease-modifying therapy exists; management is supportive, including treatment of acidosis, seizures, dystonia, feeding support, and avoidance of mitochondrial toxins such as sodium valproate. GeneReviews advises that sodium valproate, medications that cause acidosis, and dichloroacetate should be avoided or used with caution, and that anesthesia requires careful consideration to avoid precipitating respiratory failure.
Target Phenotypes: Seizure ↗ Dystonia ↗ Lactic acidosis ↗
Show evidence (2 references)
PMID:20301352 SUPPORT Human Clinical
"Treatment of manifestations: Treatment is supportive."
GeneReviews establishes that management of the Leigh syndrome spectrum is supportive, with no disease-modifying therapy.
PMID:20301352 SUPPORT Human Clinical
"Sodium valproate, medications that cause acidosis, and dichloroacetate should be avoided or used with caution;"
GeneReviews specifies agents to avoid in the Leigh syndrome spectrum, including sodium valproate and dichloroacetate.
Genetic counseling
Action: genetic counseling MAXO:0000079
Genetic counseling addresses the diverse inheritance patterns (mitochondrial, autosomal recessive, X-linked) and reproductive options.
Show evidence (1 reference)
PMID:20301352 SUPPORT Human Clinical
"Mitochondrial DNA-LSS is transmitted by maternal inheritance."
GeneReviews confirms maternal inheritance for the mtDNA-associated Leigh syndrome spectrum, a key counseling point alongside the nuclear (autosomal recessive and X-linked) forms.
🔬

Clinical Trials

1
NCT01721733 PHASE_II COMPLETED
Phase 2B randomized, placebo-controlled, double-blind trial of EPI-743 (vatiquinone), an oral para-benzoquinone redox modulator, in children with Leigh syndrome. The trial did not lead to an approved therapy; management remains supportive.
Target Phenotypes: Respiratory distress ↗ Developmental regression ↗
Show evidence (1 reference)
clinicaltrials:NCT01721733 SUPPORT Human Clinical
"The purpose of this study is to evaluate the effects of EPI-743 in children with Leigh syndrome on disease severity, neuromuscular function, respiratory function, disease morbidity and mortality and disease associated biomarkers."
A completed Phase 2B randomized controlled trial that tested EPI-743 (vatiquinone) against disease-severity, neuromuscular, and respiratory endpoints in children with Leigh syndrome.
{ }

Source YAML

click to show 
name: Leigh Syndrome
creation_date: '2026-05-30T00:00:00Z'
description: >-
  Leigh syndrome (subacute necrotizing encephalomyelopathy) is a genetically
  heterogeneous mitochondrial disorder of cellular energy metabolism. It is the
  most common pediatric presentation of mitochondrial disease and is defined
  neuropathologically by bilateral, symmetric necrotic lesions of the basal
  ganglia, thalamus, and brainstem. The shared biochemical defect is impaired
  oxidative phosphorylation/ATP production, most frequently from isolated
  complex I deficiency, complex IV (cytochrome c oxidase) deficiency, MT-ATP6
  (complex V) dysfunction, or pyruvate dehydrogenase complex deficiency. More
  than 75 causative genes are known across the mitochondrial and nuclear
  genomes. Onset is typically in infancy or early childhood with psychomotor
  regression, hypotonia, brainstem and basal-ganglia dysfunction, and lactic
  acidosis.
category: Mendelian
parents:
- hereditary disease
- mitochondrial disease
disease_term:
  preferred_term: Leigh syndrome
  term:
    id: MONDO:0009723
    label: Leigh syndrome
has_subtypes:
- name: MILS
  display_name: Maternally-inherited Leigh syndrome (MT-ATP6)
  description: >-
    Maternally inherited Leigh syndrome caused by pathogenic mitochondrial DNA
    variants, most commonly MT-ATP6 nucleotide 8993 substitutions, with
    severity dependent on heteroplasmy.
  subtype_term:
    preferred_term: maternally-inherited Leigh syndrome
    term:
      id: MONDO:0016814
      label: maternally-inherited Leigh syndrome
- name: French-Canadian
  display_name: French-Canadian (Saguenay-Lac-Saint-Jean) type
  description: >-
    Congenital lactic acidosis of the Saguenay-Lac-Saint-Jean region caused by
    biallelic LRPPRC variants, presenting as a complex IV (cytochrome c
    oxidase)-deficient Leigh syndrome.
  subtype_term:
    preferred_term: congenital lactic acidosis, Saguenay-Lac-Saint-Jean type
    term:
      id: MONDO:0009069
      label: congenital lactic acidosis, Saguenay-Lac-Saint-Jean type
- name: Leigh with cardiomyopathy
  display_name: Leigh syndrome with cardiomyopathy
  description: >-
    Leigh syndrome presentations with prominent hypertrophic cardiomyopathy,
    seen with several nuclear assembly-factor and mtDNA defects.
  subtype_term:
    preferred_term: Leigh syndrome with cardiomyopathy
    term:
      id: MONDO:0019083
      label: Leigh syndrome with cardiomyopathy
- name: Adult
  display_name: Adult subacute necrotizing encephalomyelopathy
  description: >-
    Rare adult-onset form of subacute necrotizing encephalomyelopathy with the
    characteristic symmetric brainstem and basal-ganglia lesions.
  subtype_term:
    preferred_term: necrotizing encephalomyelopathy, subacute, of Leigh, adult
    term:
      id: MONDO:0008069
      label: necrotizing encephalomyelopathy, subacute, of Leigh, adult
pathophysiology:
- name: Oxidative phosphorylation deficiency
  description: >-
    The unifying biochemical lesion in Leigh syndrome is impaired mitochondrial
    oxidative phosphorylation, reducing ATP synthesis in tissues with high
    energy demand. Causative defects converge on the respiratory chain
    complexes (most often complex I), complex IV, ATP synthase (complex V), or
    upstream pyruvate oxidation.
  biological_processes:
  - preferred_term: oxidative phosphorylation
    modifier: DECREASED
    term:
      id: GO:0006119
      label: oxidative phosphorylation
  - preferred_term: proton motive force-driven mitochondrial ATP synthesis
    modifier: DECREASED
    term:
      id: GO:0042776
      label: proton motive force-driven mitochondrial ATP synthesis
  chemical_entities:
  - preferred_term: ATP
    modifier: DECREASED
    term:
      id: CHEBI:15422
      label: ATP
  evidence:
  - reference: PMID:26506407
    reference_title: 'Leigh syndrome: One disorder, more than 75 monogenic causes.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Leigh syndrome is the most common pediatric presentation of mitochondrial disease.
    explanation: >-
      This review establishes Leigh syndrome as the prototypical pediatric mitochondrial
      (oxidative phosphorylation) disorder.
  - reference: PMID:26506407
    reference_title: 'Leigh syndrome: One disorder, more than 75 monogenic causes.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This neurodegenerative disorder is genetically heterogeneous, and to date
      pathogenic mutations in >75 genes have been identified, encoded by 2
      genomes (mitochondrial and nuclear).
    explanation: >-
      Supports the convergence of >75 mitochondrial and nuclear genes on a shared
      defect of mitochondrial energy generation.
  downstream:
  - target: Lactic acidosis
    causal_link_type: DIRECT
    description: >-
      Impaired pyruvate oxidation and respiratory-chain flux shift metabolism
      toward anaerobic glycolysis, raising lactate.
  - target: Energy-dependent neuronal vulnerability
    causal_link_type: DIRECT
    description: >-
      Energy failure preferentially injures metabolically active neurons of the
      basal ganglia and brainstem.
- name: Complex I deficiency
  description: >-
    Isolated deficiency of NADH:ubiquinone oxidoreductase (respiratory chain
    complex I) is the single most common biochemical cause of Leigh syndrome,
    arising from mtDNA MT-ND subunit variants or nuclear NDUFS/NDUFV/NDUFA
    subunit and assembly-factor defects.
  genes:
  - preferred_term: NDUFS4
    term:
      id: hgnc:7711
      label: NDUFS4
  - preferred_term: NDUFV1
    term:
      id: hgnc:7716
      label: NDUFV1
  - preferred_term: MT-ND5
    term:
      id: hgnc:7461
      label: MT-ND5
  molecular_functions:
  - preferred_term: NADH dehydrogenase (ubiquinone) activity
    modifier: DECREASED
    term:
      id: GO:0008137
      label: NADH dehydrogenase (ubiquinone) activity
  cellular_components:
  - preferred_term: NADH dehydrogenase complex
    term:
      id: GO:0030964
      label: NADH dehydrogenase complex
  biological_processes:
  - preferred_term: mitochondrial electron transport, NADH to ubiquinone
    modifier: DECREASED
    term:
      id: GO:0006120
      label: mitochondrial electron transport, NADH to ubiquinone
  evidence:
  - reference: PMID:38177503
    reference_title: Structural insights into respiratory complex I deficiency and assembly from the mitochondrial disease-related ndufs4(-/-) mouse.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Complex I mutations cause neuromuscular, mitochondrial diseases, such as
      Leigh Syndrome, but their molecular-level consequences remain poorly
      understood.
    explanation: >-
      Establishes complex I (NADH:ubiquinone oxidoreductase) deficiency as a cause of
      Leigh syndrome; the ndufs4-/- mouse is the canonical complex I-linked disease model.
  - reference: PMID:38177503
    reference_title: Structural insights into respiratory complex I deficiency and assembly from the mitochondrial disease-related ndufs4(-/-) mouse.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Cryo-EM analyses of the complex I from ndufs4-/- mouse hearts revealed a
      loose association of the NADH-dehydrogenase module
    explanation: >-
      Structural data show that loss of subunit NDUFS4 destabilizes the NADH-dehydrogenase
      module of complex I, the molecular basis of complex I-deficient Leigh syndrome.
  downstream:
  - target: Oxidative phosphorylation deficiency
    causal_link_type: DIRECT
    description: Reduced complex I activity lowers respiratory-chain flux and ATP output.
- name: Complex IV (cytochrome c oxidase) deficiency
  description: >-
    Cytochrome c oxidase deficiency, classically from SURF1 assembly-factor loss
    or LRPPRC (French-Canadian Leigh) defects, is a major cause of Leigh
    syndrome with reduced terminal electron transfer to oxygen.
  genes:
  - preferred_term: SURF1
    term:
      id: hgnc:11474
      label: SURF1
  - preferred_term: LRPPRC
    term:
      id: hgnc:15714
      label: LRPPRC
  molecular_functions:
  - preferred_term: cytochrome-c oxidase activity
    modifier: DECREASED
    term:
      id: GO:0004129
      label: cytochrome-c oxidase activity
  biological_processes:
  - preferred_term: mitochondrial respiratory chain complex IV assembly
    modifier: DECREASED
    term:
      id: GO:0033617
      label: mitochondrial respiratory chain complex IV assembly
  evidence:
  - reference: PMID:9837813
    reference_title: Mutations of SURF-1 in Leigh disease associated with cytochrome c oxidase deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Sequence analysis of SURF-1 revealed mutations in numerous DNA samples
      from LD(COX-) patients, indicating that this gene is responsible for the
      major complementation group in this important mitochondrial disorder.
    explanation: >-
      Identifies SURF1 (a cytochrome c oxidase assembly factor) as the major cause of
      Leigh disease with cytochrome c oxidase (complex IV) deficiency.
  - reference: PMID:12529507
    reference_title: Identification of a gene causing human cytochrome c oxidase deficiency by integrative genomics.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Resequencing identified two mutations on two independent haplotypes,
      providing definitive genetic proof that LRPPRC indeed causes LSFC.
    explanation: >-
      Establishes LRPPRC as the cause of Leigh syndrome, French-Canadian type, a complex
      IV (cytochrome c oxidase) deficiency.
  downstream:
  - target: Oxidative phosphorylation deficiency
    causal_link_type: DIRECT
    description: Loss of cytochrome c oxidase blocks terminal electron transport.
- name: MT-ATP6 ATP synthase (complex V) dysfunction
  description: >-
    Pathogenic MT-ATP6 variants, especially nucleotide 8993 substitutions,
    impair the proton-translocating sector of ATP synthase and produce
    maternally inherited Leigh syndrome when heteroplasmy is high.
  genes:
  - preferred_term: MT-ATP6
    term:
      id: hgnc:7414
      label: MT-ATP6
  molecular_functions:
  - preferred_term: proton-transporting ATP synthase activity, rotational mechanism
    modifier: DECREASED
    term:
      id: GO:0046933
      label: proton-transporting ATP synthase activity, rotational mechanism
  cellular_components:
  - preferred_term: proton-transporting ATP synthase complex
    term:
      id: GO:0045259
      label: proton-transporting ATP synthase complex
  evidence:
  - reference: PMID:16525806
    reference_title: "NARP-MILS syndrome caused by 8993 T>G mitochondrial DNA mutation: a clinical, genetic and neuropathological study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The 8993 T>G mutation in mitochondrial DNA has been associated with
      variable syndromes of differing severity ranging from maternally inherited
      Leigh's syndrome (MILS) to neuropathy, ataxia, retinitis pigmentosa
      (NARP), depending on the mutation loads in affected patients.
    explanation: >-
      Supports the canonical MT-ATP6 nucleotide 8993 variant as a cause of maternally
      inherited Leigh syndrome, with severity governed by heteroplasmy (mutation load).
  downstream:
  - target: Oxidative phosphorylation deficiency
    causal_link_type: DIRECT
    description: Defective ATP synthase coupling decreases ATP generation.
- name: Pyruvate dehydrogenase complex deficiency
  description: >-
    X-linked PDHA1 and related pyruvate dehydrogenase complex defects block
    conversion of pyruvate to acetyl-CoA, depriving the TCA cycle of substrate
    and producing a Leigh phenotype with prominent lactic acidosis.
  genes:
  - preferred_term: PDHA1
    term:
      id: hgnc:8806
      label: PDHA1
  biological_processes:
  - preferred_term: pyruvate metabolic process
    modifier: DECREASED
    term:
      id: GO:0006090
      label: pyruvate metabolic process
  evidence:
  - reference: PMID:33661577
    reference_title: 'Clinical exome sequencing reveals a mutation in PDHA1 in Leigh syndrome: A case of a Chinese boy with lethal neuropathy.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A PDHA1 mutation (NM_000284.4:c.1167_1170del) was identified as the
      underlying cause.
    explanation: >-
      A case in which an X-linked PDHA1 (pyruvate dehydrogenase E1-alpha) mutation
      underlies a Leigh syndrome presentation.
  downstream:
  - target: Lactic acidosis
    causal_link_type: DIRECT
    description: Blocked pyruvate oxidation diverts pyruvate to lactate.
  - target: Oxidative phosphorylation deficiency
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: Reduced acetyl-CoA limits TCA-cycle reducing equivalents for the respiratory chain.
- name: Lactic acidosis
  description: >-
    Impaired aerobic ATP production shifts metabolism to anaerobic glycolysis,
    elevating lactate in blood and cerebrospinal fluid.
  chemical_entities:
  - preferred_term: lactate
    modifier: INCREASED
    term:
      id: CHEBI:24996
      label: lactate
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Decompensation (often with elevated lactate levels in blood and/or
      cerebrospinal fluid) is typically associated with developmental delay
      and/or regression.
    explanation: >-
      GeneReviews documents elevated blood and CSF lactate during metabolic decompensation,
      the biochemical signature of impaired aerobic ATP production.
  downstream:
  - target: Energy-dependent neuronal vulnerability
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: Systemic and CNS acidosis compounds energetic stress on vulnerable neurons.
- name: Energy-dependent neuronal vulnerability
  description: >-
    Chronic energy deficiency injures metabolically demanding neurons and glia,
    producing the characteristic bilateral symmetric necrotic lesions, capillary
    proliferation, and gliosis of the basal ganglia, thalamus, and brainstem
    that define Leigh syndrome neuropathology.
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  - preferred_term: astrocyte
    term:
      id: CL:0000127
      label: astrocyte
  locations:
  - preferred_term: basal ganglion
    term:
      id: UBERON:0002420
      label: basal ganglion
  - preferred_term: brainstem
    term:
      id: UBERON:0002298
      label: brainstem
  evidence:
  - reference: PMID:16525806
    reference_title: "NARP-MILS syndrome caused by 8993 T>G mitochondrial DNA mutation: a clinical, genetic and neuropathological study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Post-mortem studies of the brain in one affected member clinically
      presenting with a neurological disorder intermediate between adult Leigh's
      syndrome and NARP showed symmetrical lesions of the basal ganglia and
      brainstem closely resembling those usually described in typical Leigh's
      syndrome.
    explanation: >-
      Post-mortem neuropathology documents the bilateral symmetric basal-ganglia and
      brainstem lesions that define Leigh syndrome and reflect regional energy-dependent
      neuronal vulnerability.
  downstream:
  - target: Developmental regression
    causal_link_type: DIRECT
    description: Progressive lesion accumulation drives loss of acquired milestones.
phenotypes:
- name: Developmental regression
  category: Neurologic
  description: Loss of previously acquired motor and cognitive milestones is a defining feature.
  phenotype_term:
    preferred_term: Developmental regression
    term:
      id: HP:0002376
      label: Developmental regression
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Decompensation (often with elevated lactate levels in blood and/or
      cerebrospinal fluid) is typically associated with developmental delay
      and/or regression.
    explanation: GeneReviews documents developmental delay and regression as a core feature of the Leigh syndrome spectrum.
- name: Hypotonia
  category: Neurologic
  description: Central hypotonia is an early and common sign.
  phenotype_term:
    preferred_term: Hypotonia
    term:
      id: HP:0001252
      label: Hypotonia
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neurologic features include hypotonia, spasticity, seizures, movement
      disorders, cerebellar ataxia, and peripheral neuropathy.
    explanation: GeneReviews lists hypotonia among the core neurologic features of the Leigh syndrome spectrum.
- name: Dystonia
  category: Neurologic
  description: Basal-ganglia injury produces dystonia and other movement abnormalities.
  phenotype_term:
    preferred_term: Dystonia
    term:
      id: HP:0001332
      label: Dystonia
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neurologic features include hypotonia, spasticity, seizures, movement
      disorders, cerebellar ataxia, and peripheral neuropathy.
    explanation: >-
      GeneReviews lists movement disorders among core neurologic features; dystonia is
      the characteristic basal-ganglia movement disorder of Leigh syndrome.
- name: Ataxia
  category: Neurologic
  description: Cerebellar and brainstem involvement cause gait and limb ataxia.
  phenotype_term:
    preferred_term: Ataxia
    term:
      id: HP:0001251
      label: Ataxia
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neurologic features include hypotonia, spasticity, seizures, movement
      disorders, cerebellar ataxia, and peripheral neuropathy.
    explanation: GeneReviews lists cerebellar ataxia among the core neurologic features of the Leigh syndrome spectrum.
- name: Spasticity
  category: Neurologic
  description: Pyramidal-tract involvement produces spasticity in the Leigh syndrome spectrum.
  phenotype_term:
    preferred_term: Spasticity
    term:
      id: HP:0001257
      label: Spasticity
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neurologic features include hypotonia, spasticity, seizures, movement
      disorders, cerebellar ataxia, and peripheral neuropathy.
    explanation: GeneReviews lists spasticity among the core neurologic features of the Leigh syndrome spectrum.
- name: Peripheral neuropathy
  category: Neurologic
  description: Peripheral nerve involvement is a recognized neurologic feature of the Leigh syndrome spectrum.
  phenotype_term:
    preferred_term: Peripheral neuropathy
    term:
      id: HP:0009830
      label: Peripheral neuropathy
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neurologic features include hypotonia, spasticity, seizures, movement
      disorders, cerebellar ataxia, and peripheral neuropathy.
    explanation: GeneReviews lists peripheral neuropathy among the core neurologic features of the Leigh syndrome spectrum.
- name: Nystagmus
  category: Ophthalmologic
  description: Brainstem involvement commonly produces nystagmus and ophthalmoplegia.
  phenotype_term:
    preferred_term: Nystagmus
    term:
      id: HP:0000639
      label: Nystagmus
- name: Ophthalmoplegia
  category: Ophthalmologic
  description: External ophthalmoplegia reflects brainstem oculomotor involvement.
  phenotype_term:
    preferred_term: Ophthalmoplegia
    term:
      id: HP:0000602
      label: Ophthalmoplegia
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Brain stem dysfunction may manifest with respiratory symptoms, swallowing
      difficulties, ophthalmoparesis, and abnormalities in thermoregulation.
    explanation: GeneReviews attributes ophthalmoparesis (ophthalmoplegia) to brainstem dysfunction in the Leigh syndrome spectrum.
- name: Respiratory abnormalities
  category: Respiratory
  description: Brainstem dysfunction causes abnormal respiratory patterns and respiratory failure.
  phenotype_term:
    preferred_term: Respiratory distress
    term:
      id: HP:0002098
      label: Respiratory distress
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Brain stem dysfunction may manifest with respiratory symptoms, swallowing
      difficulties, ophthalmoparesis, and abnormalities in thermoregulation.
    explanation: >-
      GeneReviews attributes respiratory symptoms to brainstem dysfunction; respiratory
      failure is a leading cause of death in the Leigh syndrome spectrum.
- name: Seizures
  category: Neurologic
  description: Seizures occur in a substantial fraction of patients.
  phenotype_term:
    preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neurologic features include hypotonia, spasticity, seizures, movement
      disorders, cerebellar ataxia, and peripheral neuropathy.
    explanation: GeneReviews lists seizures among the core neurologic features of the Leigh syndrome spectrum.
- name: Feeding difficulties
  category: Gastrointestinal
  description: Bulbar dysfunction produces feeding difficulties and failure to thrive.
  phenotype_term:
    preferred_term: Feeding difficulties
    term:
      id: HP:0011968
      label: Feeding difficulties
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Brain stem dysfunction may manifest with respiratory symptoms, swallowing
      difficulties, ophthalmoparesis, and abnormalities in thermoregulation.
    explanation: GeneReviews attributes swallowing (feeding) difficulties to brainstem dysfunction in the Leigh syndrome spectrum.
- name: Lactic acidosis
  category: Metabolic
  description: Elevated blood and CSF lactate is a hallmark biochemical finding.
  phenotype_term:
    preferred_term: Lactic acidosis
    term:
      id: HP:0003128
      label: Lactic acidosis
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Decompensation (often with elevated lactate levels in blood and/or
      cerebrospinal fluid) is typically associated with developmental delay
      and/or regression.
    explanation: GeneReviews documents elevated blood and CSF lactate as a hallmark of metabolic decompensation in the Leigh syndrome spectrum.
- name: Abnormal basal ganglia morphology
  category: Neurologic
  description: Bilateral symmetric basal-ganglia and brainstem lesions on MRI are diagnostic hallmarks.
  phenotype_term:
    preferred_term: Abnormal basal ganglia morphology
    term:
      id: HP:0002134
      label: Abnormal basal ganglia morphology
  evidence:
  - reference: PMID:16525806
    reference_title: "NARP-MILS syndrome caused by 8993 T>G mitochondrial DNA mutation: a clinical, genetic and neuropathological study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Post-mortem studies of the brain in one affected member clinically
      presenting with a neurological disorder intermediate between adult Leigh's
      syndrome and NARP showed symmetrical lesions of the basal ganglia and
      brainstem closely resembling those usually described in typical Leigh's
      syndrome.
    explanation: >-
      Neuropathology documents the symmetric basal-ganglia lesions that are the
      diagnostic hallmark of Leigh syndrome.
- name: Cardiomyopathy
  category: Cardiovascular
  subtype: Leigh with cardiomyopathy
  description: >-
    Cardiomyopathy is a major extraneurologic manifestation of the Leigh
    syndrome spectrum and, with cardiac failure, a leading cause of death.
  phenotype_term:
    preferred_term: Cardiomyopathy
    term:
      id: HP:0001638
      label: Cardiomyopathy
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Extraneurologic manifestations may include poor weight gain,
      cardiomyopathy, and conduction defects.
    explanation: >-
      GeneReviews lists cardiomyopathy among the extraneurologic manifestations of the
      Leigh syndrome spectrum; cardiac failure is a leading cause of death.
genetic:
- name: NDUFS4
  gene_term:
    preferred_term: NDUFS4
    term:
      id: hgnc:7711
      label: NDUFS4
  association: >-
    Biallelic NDUFS4 loss-of-function variants cause complex I-deficient Leigh
    syndrome.
  inheritance:
  - name: Autosomal recessive inheritance
    inheritance_term:
      preferred_term: Autosomal recessive inheritance
      term:
        id: HP:0000007
        label: Autosomal recessive inheritance
  evidence:
  - reference: PMID:38177503
    reference_title: Structural insights into respiratory complex I deficiency and assembly from the mitochondrial disease-related ndufs4(-/-) mouse.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      we use a popular complex I-linked mitochondrial disease model, the
      ndufs4-/- mouse, to define the structural, biochemical, and functional
      consequences of the absence of subunit NDUFS4.
    explanation: >-
      The ndufs4-/- mouse is an established model of complex I-deficient Leigh syndrome,
      supporting NDUFS4 loss as a cause of the disorder.
- name: NDUFV1
  gene_term:
    preferred_term: NDUFV1
    term:
      id: hgnc:7716
      label: NDUFV1
  association: >-
    Biallelic variants in the nuclear-encoded complex I core subunit gene NDUFV1
    cause complex I-deficient Leigh syndrome.
  inheritance:
  - name: Autosomal recessive inheritance
    inheritance_term:
      preferred_term: Autosomal recessive inheritance
      term:
        id: HP:0000007
        label: Autosomal recessive inheritance
  evidence:
  - reference: PMID:26506407
    reference_title: 'Leigh syndrome: One disorder, more than 75 monogenic causes.'
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This neurodegenerative disorder is genetically heterogeneous, and to date
      pathogenic mutations in >75 genes have been identified, encoded by 2
      genomes (mitochondrial and nuclear).
    explanation: >-
      NDUFV1 is one of the nuclear-encoded complex I subunit genes among the >75
      monogenic causes of Leigh syndrome catalogued in this review; the review
      supports nuclear complex I subunit genes as a cause but does not name NDUFV1
      individually, hence PARTIAL.
- name: SURF1
  gene_term:
    preferred_term: SURF1
    term:
      id: hgnc:11474
      label: SURF1
  association: >-
    Biallelic SURF1 variants impair cytochrome c oxidase assembly and are a
    common cause of complex IV-deficient Leigh syndrome.
  inheritance:
  - name: Autosomal recessive inheritance
    inheritance_term:
      preferred_term: Autosomal recessive inheritance
      term:
        id: HP:0000007
        label: Autosomal recessive inheritance
  evidence:
  - reference: PMID:9837813
    reference_title: Mutations of SURF-1 in Leigh disease associated with cytochrome c oxidase deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Sequence analysis of SURF-1 revealed mutations in numerous DNA samples
      from LD(COX-) patients, indicating that this gene is responsible for the
      major complementation group in this important mitochondrial disorder.
    explanation: Identifies SURF1 as the major causative gene for cytochrome c oxidase-deficient Leigh disease.
- name: LRPPRC
  gene_term:
    preferred_term: LRPPRC
    term:
      id: hgnc:15714
      label: LRPPRC
  association: >-
    Biallelic LRPPRC variants cause the French-Canadian (Saguenay-Lac-Saint-Jean)
    type of cytochrome c oxidase (complex IV)-deficient Leigh syndrome.
  inheritance:
  - name: Autosomal recessive inheritance
    inheritance_term:
      preferred_term: Autosomal recessive inheritance
      term:
        id: HP:0000007
        label: Autosomal recessive inheritance
  evidence:
  - reference: PMID:12529507
    reference_title: Identification of a gene causing human cytochrome c oxidase deficiency by integrative genomics.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Resequencing identified two mutations on two independent haplotypes,
      providing definitive genetic proof that LRPPRC indeed causes LSFC.
    explanation: >-
      Establishes biallelic LRPPRC variants as the cause of Leigh syndrome,
      French-Canadian type (LSFC), a complex IV (cytochrome c oxidase) deficiency.
- name: MT-ATP6
  gene_term:
    preferred_term: MT-ATP6
    term:
      id: hgnc:7414
      label: MT-ATP6
  association: >-
    Maternally inherited MT-ATP6 nucleotide 8993 variants cause maternally
    inherited Leigh syndrome with heteroplasmy-dependent severity.
  inheritance:
  - name: Mitochondrial inheritance
    inheritance_term:
      preferred_term: Mitochondrial inheritance
      term:
        id: HP:0001427
        label: Mitochondrial inheritance
  evidence:
  - reference: PMID:16525806
    reference_title: "NARP-MILS syndrome caused by 8993 T>G mitochondrial DNA mutation: a clinical, genetic and neuropathological study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The 8993 T>G mutation in mitochondrial DNA has been associated with
      variable syndromes of differing severity ranging from maternally inherited
      Leigh's syndrome (MILS) to neuropathy, ataxia, retinitis pigmentosa
      (NARP), depending on the mutation loads in affected patients.
    explanation: Supports MT-ATP6 m.8993T>G as a maternally inherited cause of Leigh syndrome (MILS).
- name: PDHA1
  gene_term:
    preferred_term: PDHA1
    term:
      id: hgnc:8806
      label: PDHA1
  association: >-
    X-linked PDHA1 variants cause pyruvate dehydrogenase deficiency presenting
    as Leigh syndrome.
  inheritance:
  - name: X-linked inheritance
    inheritance_term:
      preferred_term: X-linked inheritance
      term:
        id: HP:0001417
        label: X-linked inheritance
  evidence:
  - reference: PMID:33661577
    reference_title: 'Clinical exome sequencing reveals a mutation in PDHA1 in Leigh syndrome: A case of a Chinese boy with lethal neuropathy.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Leigh syndrome, the most common mitochondrial syndrome in pediatrics, has
      diverse clinical manifestations and is genetically heterogeneous.
    explanation: >-
      Case report establishing an X-linked PDHA1 frameshift mutation as the cause of a
      Leigh syndrome presentation.
progression:
- phase: Infantile onset
  age_range: Typically before age 2 years
  notes: >-
    Classic Leigh syndrome presents in infancy or early childhood, often after an
    intercurrent illness or metabolic stressor, with psychomotor regression.
  evidence:
  - reference: PMID:31996241
    reference_title: 'Molecular basis of Leigh syndrome: a current look.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The first description given by Leigh pointed out neurological symptoms in
      children under 2 years and premature death.
    explanation: Supports typical onset before age two years with a severe early course.
- phase: Progressive course
  notes: >-
    Disease burden increases over time, and early age at onset is a major adverse
    prognostic factor for mortality.
  evidence:
  - reference: PMID:34716721
    reference_title: 'Natural History of Leigh Syndrome: A Study of Disease Burden and Progression.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the percentage of children with severe disease burden doubled (22% → 42%)
    explanation: Longitudinal natural-history data show measurable progression of disease burden over time.
  - reference: PMID:31967322
    reference_title: 'Mortality of Japanese patients with Leigh syndrome: Effects of age at onset and genetic diagnosis.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Mortality rate of patients with onset before 6 months of age was
      significantly higher than that of onset after 6 months.
    explanation: A national cohort shows that early age at onset is associated with significantly higher mortality.
  - reference: PMID:31967322
    reference_title: 'Mortality of Japanese patients with Leigh syndrome: Effects of age at onset and genetic diagnosis.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Nearly 90% of deaths occurred by age 6.
    explanation: Quantifies the historically poor survival of classic early-onset Leigh syndrome.
environmental: []
treatments:
- name: Supportive mitochondrial disease management
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
  description: >-
    No disease-modifying therapy exists; management is supportive, including
    treatment of acidosis, seizures, dystonia, feeding support, and avoidance of
    mitochondrial toxins such as sodium valproate. GeneReviews advises that
    sodium valproate, medications that cause acidosis, and dichloroacetate
    should be avoided or used with caution, and that anesthesia requires careful
    consideration to avoid precipitating respiratory failure.
  target_phenotypes:
  - preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
  - preferred_term: Dystonia
    term:
      id: HP:0001332
      label: Dystonia
  - preferred_term: Lactic acidosis
    term:
      id: HP:0003128
      label: Lactic acidosis
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Treatment of manifestations: Treatment is supportive."
    explanation: GeneReviews establishes that management of the Leigh syndrome spectrum is supportive, with no disease-modifying therapy.
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Sodium valproate, medications that cause acidosis, and dichloroacetate
      should be avoided or used with caution;
    explanation: >-
      GeneReviews specifies agents to avoid in the Leigh syndrome spectrum, including
      sodium valproate and dichloroacetate.
- name: Genetic counseling
  treatment_term:
    preferred_term: genetic counseling
    term:
      id: MAXO:0000079
      label: genetic counseling
  description: >-
    Genetic counseling addresses the diverse inheritance patterns (mitochondrial,
    autosomal recessive, X-linked) and reproductive options.
  evidence:
  - reference: PMID:20301352
    reference_title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: Mitochondrial DNA-LSS is transmitted by maternal inheritance.
    explanation: >-
      GeneReviews confirms maternal inheritance for the mtDNA-associated Leigh syndrome
      spectrum, a key counseling point alongside the nuclear (autosomal recessive and
      X-linked) forms.
references:
- reference: PMID:20301352
  title: Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
  tags:
  - GeneReviews
  findings: []
- reference: PMID:26425749
  title: Nuclear Gene-Encoded Leigh Syndrome Spectrum Overview.
  tags:
  - GeneReviews
  findings: []
clinical_trials:
- name: NCT01721733
  phase: PHASE_II
  status: COMPLETED
  description: >-
    Phase 2B randomized, placebo-controlled, double-blind trial of EPI-743
    (vatiquinone), an oral para-benzoquinone redox modulator, in children with
    Leigh syndrome. The trial did not lead to an approved therapy; management
    remains supportive.
  target_phenotypes:
  - preferred_term: Respiratory distress
    term:
      id: HP:0002098
      label: Respiratory distress
  - preferred_term: Developmental regression
    term:
      id: HP:0002376
      label: Developmental regression
  evidence:
  - reference: clinicaltrials:NCT01721733
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The purpose of this study is to evaluate the effects of EPI-743 in
      children with Leigh syndrome on disease severity, neuromuscular function,
      respiratory function, disease morbidity and mortality and disease
      associated biomarkers.
    explanation: >-
      A completed Phase 2B randomized controlled trial that tested EPI-743
      (vatiquinone) against disease-severity, neuromuscular, and respiratory
      endpoints in children with Leigh syndrome.
datasets: []
📚

References & Deep Research

References

2
PMID:20301352
Mitochondrial DNA-Associated Leigh Syndrome Spectrum.
No top-level findings curated for this source.
PMID:26425749
Nuclear Gene-Encoded Leigh Syndrome Spectrum Overview.
No top-level findings curated for this source.

Deep Research

1
Falcon ▸
1. Disease Information
Edison Scientific Literature 33 citations 2026-05-30T19:59:45.864347

1. Disease Information

1.1 Concise overview (current understanding)

Leigh syndrome is the most frequent pediatric manifestation of primary mitochondrial disease, typically presenting in infancy/early childhood with developmental delay or regression and progressive neurologic dysfunction; multisystem involvement (e.g., cardiac, hepatic, renal, GI) can occur. (lake2016leighsyndromeone pages 1-6, baldo2024acomprehensiveapproach pages 1-2)

Neuroimaging hallmark: bilateral symmetric basal ganglia and/or brainstem lesions, visible as focal T2 hyperintensities; MR spectroscopy can show elevated lactate. (lake2016leighsyndromeone pages 1-6, baldo2024acomprehensiveapproach pages 1-2, lim2022naturalhistoryof pages 2-3)

1.2 Synonyms / alternative names

  • Subacute necrotizing encephalomyelopathy (classical terminology) (lake2016leighsyndromeone pages 1-6, mccormick2023expertpanelcuration pages 9-10)
  • Leigh syndrome spectrum (LSS): nomenclature used to encompass classic Leigh plus “Leigh-like” phenotypes in modern clinical genetics and ClinGen curation. (baldo2024acomprehensiveapproach pages 1-2, mccormick2023expertpanelcuration pages 9-10)

1.3 Key identifiers

Evidence retrieved in this run supports disease-level identifiers primarily through literature and ClinGen-oriented curation, but did not contain explicit Orphanet, ICD-10/ICD-11, MeSH, or MONDO IDs in the accessible text snippets. Therefore, those specific codes cannot be asserted here from tool-retrieved evidence.

1.4 Evidence source type

The report integrates: - Aggregated disease-level resources and expert consensus (ClinGen curation; diagnostic review) (mccormick2023expertpanelcuration pages 9-10, baldo2024acomprehensiveapproach pages 1-2) - Cohort/natural history studies (human observational) (lim2022naturalhistoryof pages 2-3, stenton2022leighsyndromea pages 1-1) - Patient registry (patient-/caregiver-reported outcomes) (zilber2023leighsyndromeglobal pages 1-2, zilber2023leighsyndromeglobal pages 8-11, zilber2023leighsyndromeglobal pages 2-4, zilber2023leighsyndromeglobal pages 11-12) - Model organism mechanistic studies (e.g., Ndufs4−/− mouse) (lake2016leighsyndromeone pages 19-24, spencer2023volatileanaesthetictoxicity pages 1-2)

2. Etiology

2.1 Primary causal factors

Primary cause: inherited mitochondrial dysfunction leading to impaired ATP generation, commonly due to defects in oxidative phosphorylation (OXPHOS) and/or pyruvate dehydrogenase complex (PDHc). (lake2016leighsyndromeone pages 1-6)

2.2 Genetic risk factors (causal variants/genes)

LS/LSS is highly genetically heterogeneous, caused by pathogenic variants in both nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) genes. A key diagnostic challenge is establishing gene–disease relationships across “>100 monogenic causes” spanning both genomes. (mccormick2023expertpanelcuration pages 9-10, lake2016leighsyndromeone pages 1-6)

ClinGen/Expert-panel evidence (2023): The ClinGen Mitochondrial Disease Gene Curation Expert Panel (Mito GCEP) curated 113 primary mitochondrial disease genes for LSS and evaluated 114 gene–disease relationships (GDRs), classified as 31 definitive (27%), 38 moderate (33%), 43 limited (38%), and 2 disputed (2%). Inheritance among curated genes was predominantly autosomal recessive (90), with fewer maternal (16), autosomal dominant (5), and X-linked (3). (mccormick2023expertpanelcuration pages 9-10, mccormick2023expertpanelcuration pages 4-5)

Commonly implicated genes/defects (examples): - Complex I deficiency (often most frequent OXPHOS defect in LS cohorts/reviews) and complex I gene involvement across both genomes (e.g., MT-ND genes; nuclear complex I genes). (lake2016leighsyndromeone pages 1-6, henke2024diseasemodelsof pages 2-5) - MT-ATP6 (complex V/ATP synthase) variants: frequently highlighted in LSS diagnostic reviews and cohorts, including m.8993T>G/C and m.9176T>C. (baldo2024acomprehensiveapproach pages 1-2, lim2022naturalhistoryof pages 2-3, baldo2024acomprehensiveapproach pages 2-4) - SURF1 (complex IV assembly factor) is repeatedly cited as a common nuclear cause in LSS frameworks. (baldo2024acomprehensiveapproach pages 1-2, stenton2022leighsyndromea pages 1-1) - PDHA1 (PDHc) appears among frequent genes in a large pediatric cohort. (stenton2022leighsyndromea pages 1-1)

2.3 Environmental risk factors / triggers

LS is Mendelian/mitochondrial in etiology; however, physiologic stressors can worsen clinical status. A 2023 preclinical study provides mechanistic evidence that volatile anesthetic exposure (isoflurane) can be toxic in a canonical LS model (Ndufs4−/−), producing hyperlactatemia, weight loss, and increased mortality in a disease-stage-dependent manner. (spencer2023volatileanaesthetictoxicity pages 1-2)

2.4 Protective factors

No validated protective variants or environmental protective factors were identified in the retrieved evidence.

2.5 Gene–environment interactions

Direct, human-proven gene–environment interaction datasets were not retrieved in this run. However, experimental evidence in Ndufs4−/− mice indicates a strong interaction between genetic mitochondrial disease state and volatile anesthetic exposure, and suggests a neuroimmune component modulating toxicity (attenuation with CSF1R inhibitor pexidartinib/PLX3397). (spencer2023volatileanaesthetictoxicity pages 1-2)

3. Phenotypes

3.1 Core phenotype spectrum (human)

Across cohorts and reviews, common clinical features include: - Developmental delay / developmental regression - Hypotonia, weakness - Ataxia, dystonia / movement disorders - Epilepsy/seizures - Feeding difficulties/poor feeding - Ophthalmologic manifestations (e.g., ophthalmoparesis/optic atrophy in classic descriptions) (lake2016leighsyndromeone pages 1-6, lim2022naturalhistoryof pages 2-3, henke2024diseasemodelsof pages 2-5)

Quantitative cohort examples - In a 209-patient cohort, common clinical/biochemical features included elevated serum lactate (144/195), global developmental delay (142/209), and developmental regression (103/209). (stenton2022leighsyndromea pages 1-1)

Registry-reported developmental impacts - In the global registry analysis, 68% of participant concerns were developmental delay/regression; 56% never achieved at least one milestone and 40% never walked. (zilber2023leighsyndromeglobal pages 11-12)

3.2 Phenotype characteristics and HPO suggestions

Below are practical phenotype-to-HPO mappings aligned with retrieved evidence.

Phenotype Type Typical onset/course (from retrieved evidence) Suggested HPO term(s)
Developmental delay/regression Neurodevelopmental Often infancy/early childhood; median onset 9 months in one cohort HP:0001263 (Global developmental delay); HP:0002376 (Developmental regression) (lim2022naturalhistoryof pages 2-3, stenton2022leighsyndromea pages 1-1)
Seizures/epilepsy Neurologic Common in LSS diagnostic discussions HP:0001250 (Seizures); HP:0001270 (Epileptic encephalopathy) (baldo2024acomprehensiveapproach pages 1-2, henke2024diseasemodelsof pages 2-5)
Hypotonia/weakness Neuromuscular Frequent sign in reviews/models HP:0001252 (Muscular hypotonia); HP:0001324 (Muscle weakness) (lake2016leighsyndromeone pages 1-6, henke2024diseasemodelsof pages 2-5)
Ataxia Neurologic Common in reviews HP:0001251 (Ataxia) (lake2016leighsyndromeone pages 1-6)
Dystonia/movement disorder Neurologic Common; registry and cohorts emphasize motor impairment HP:0001332 (Dystonia) (lake2016leighsyndromeone pages 1-6, zilber2023leighsyndromeglobal pages 8-11)
Lactic acidosis / elevated lactate Laboratory abnormality Frequent across cohorts; MRS lactate peak supportive HP:0003128 (Lactic acidemia); HP:0002151 (Increased lactate) (baldo2024acomprehensiveapproach pages 1-2, lim2022naturalhistoryof pages 2-3)
Symmetric basal ganglia/brainstem lesions Imaging finding Core neuroradiologic hallmark HP:0002136 (Bilateral basal ganglia lesions); HP:0012557 (Brainstem lesion) (conceptual mapping; supported by imaging descriptions) (lake2016leighsyndromeone pages 1-6, lim2022naturalhistoryof pages 2-3)

3.3 Quality-of-life and caregiver burden (registry data; 2023–2025)

Abstract-quotable statements (2023 registry paper): - “Reported results include demographics, diagnostic information, symptom history, loss of milestones, disease management, healthcare utilization, quality of life, and caregiver burden for 116 participants.” (zilber2023leighsyndromeglobal pages 1-2) - “Results show a high disease burden, but a relatively short time to diagnosis.” (zilber2023leighsyndromeglobal pages 1-2) - Participants “in general, are described as having a good quality of life and caregivers are overall resilient, while also reporting a significant amount of stress.” (zilber2023leighsyndromeglobal pages 1-2)

Additional quantitative registry findings (selected): - International distribution: nearly 70% outside the US, 25 countries; heavy representation in Eastern Europe and North America in early analysis. (zilber2023leighsyndromeglobal pages 8-11, zilber2023leighsyndromeglobal pages 2-4) - Healthcare utilization example: in one 3-month window, ~74% reported 0 inpatient nights; among those with any inpatient stay, mean nights were ~12.5 (SD 12.3). (zilber2023leighsyndromeglobal pages 8-11)

4. Genetic/Molecular Information

4.1 Causal genes (selected, evidence-supported)

Disease-level statement: >75 genes were recognized in a high-citation review, with continued expansion to >100 genes in more recent frameworks; ClinGen curated 113 genes as a minimum set for LSS gene–disease validity. (lake2016leighsyndromeone pages 1-6, mccormick2023expertpanelcuration pages 9-10)

Examples (non-exhaustive): - mtDNA: MT-ATP6 (e.g., m.8993T>G/C; m.9176T>C), MT-ND genes (complex I subunits) (baldo2024acomprehensiveapproach pages 1-2, lim2022naturalhistoryof pages 2-3, henke2024diseasemodelsof pages 2-5) - nDNA: SURF1, PDHA1, nuclear complex I genes and assembly factors (stenton2022leighsyndromea pages 1-1, henke2024diseasemodelsof pages 2-5)

4.2 Pathogenic variant classes and functional consequences

Retrieved sources emphasize functional consequences primarily as energy generation failure due to: - OXPHOS complex dysfunction (complex I frequently; complex IV; complex V/ATP synthase) (lake2016leighsyndromeone pages 1-6, henke2024diseasemodelsof pages 2-5) - PDHc defects impairing entry of pyruvate into the TCA cycle (lake2016leighsyndromeone pages 1-6)

Variant load/heteroplasmy (mtDNA): One natural history cohort noted mtDNA pathogenic variants in ~22% and that MT-ATP6 variants were the most frequent mtDNA causes; mtDNA heteroplasmy is a key determinant of severity in mitochondrial disease biology, although detailed allele-frequency distributions in population databases were not retrievable here. (lim2022naturalhistoryof pages 2-3)

4.3 Modifier genes / epigenetics / chromosomal abnormalities

No robust modifier-gene or epigenetic-signature evidence was retrieved in this run. (Not available from the gathered context.)

5. Environmental Information

5.1 Environmental/lifestyle/infectious contributors

No infectious causes are implicated; LS is a genetic neurometabolic disorder. However, exposures that alter mitochondrial function can be clinically relevant.

Volatile anesthetics (environmental/iatrogenic exposure): Isoflurane exposure was toxic in Ndufs4−/− mice, inducing hyperlactatemia, weight loss, and mortality; toxicity depended on neurological disease status and was attenuated by microglia/macrophage depletion using CSF1R inhibitor pexidartinib. (spencer2023volatileanaesthetictoxicity pages 1-2)

6. Mechanism / Pathophysiology

6.1 Causal chain (gene → cellular → tissue → clinical)

Upstream trigger: pathogenic variants in mtDNA or nDNA affecting mitochondrial energy generation (OXPHOS/PDHc). (lake2016leighsyndromeone pages 1-6)

Cellular consequence: reduced ATP production with compensatory glycolysis and altered redox state; biochemical accumulation of lactate/pyruvate is common. (baldo2024acomprehensiveapproach pages 1-2, henke2024diseasemodelsof pages 2-5)

Tissue vulnerability: CNS regions with high energy demand (basal ganglia/brainstem/cerebellum) develop bilateral necrotizing lesions → neurodevelopmental regression, movement disorders, seizures, respiratory failure. (lake2016leighsyndromeone pages 1-6, lim2022naturalhistoryof pages 2-3)

6.2 Molecular pathways and cellular processes (evidence-supported)

  • OXPHOS / electron transport chain dysfunction (complex I, IV, V prominent in examples). (lake2016leighsyndromeone pages 1-6, henke2024diseasemodelsof pages 2-5)
  • mTOR signaling: a high-citation review summarizes that rapamycin improved lifespan and neurodegeneration in the Ndufs4−/− LS model, supporting nutrient-sensing dysregulation as a contributory mechanism and a potential therapeutic axis. (lake2016leighsyndromeone pages 19-24)
  • Neuroimmune involvement: anesthetic toxicity in Ndufs4−/− mice was attenuated by CSF1R inhibitor pexidartinib, implicating microglia/macrophages. (spencer2023volatileanaesthetictoxicity pages 1-2)

6.3 Suggested ontology terms

GO Biological Process (examples): - GO:0006119 oxidative phosphorylation - GO:0006099 tricarboxylic acid cycle (as downstream of PDHc) - GO:0010906 regulation of glucose metabolic process (reflecting glycolytic shift)

GO Cellular Component: - GO:0005739 mitochondrion - GO:0005743 mitochondrial inner membrane - GO:0005753 mitochondrial proton-transporting ATP synthase complex

Cell Ontology (CL) likely involved: - CL:0000540 neuron - CL:0000129 microglial cell (supported by CSF1R inhibitor result in model) (spencer2023volatileanaesthetictoxicity pages 1-2)

7. Anatomical Structures Affected

7.1 Organ/system level

  • Central nervous system is primary: basal ganglia and brainstem involvement are defining. (lake2016leighsyndromeone pages 1-6, baldo2024acomprehensiveapproach pages 1-2)
  • Multisystem involvement can include muscle, eye, and heart (noted generally in reviews; detailed organ-frequency breakdown not consistently available across retrieved human cohorts in this run). (lake2016leighsyndromeone pages 1-6)

7.2 Localization (UBERON suggestions)

  • UBERON:0002421 basal ganglion
  • UBERON:0002298 brainstem
  • UBERON:0002037 cerebellum

7.3 MRI lesion distribution (quantitative cohort)

In one pediatric natural-history cohort, the commonest MRI findings were symmetrical putaminal signal abnormality (57.1%), globus pallidus (41.3%), and caudate (39.7%). (lim2022naturalhistoryof pages 2-3)

8. Temporal Development

8.1 Onset

  • Typical onset is before age 2 years, with median onset 9 months in one natural history cohort. (lake2016leighsyndromeone pages 1-6, lim2022naturalhistoryof pages 2-3)

8.2 Progression/course

  • Course is often progressive and may be rapid in severe early-onset forms; prognosis is strongly genotype- and onset-age-dependent. (lake2016leighsyndromeone pages 1-6, stenton2022leighsyndromea pages 1-1)

9. Inheritance and Population

9.1 Epidemiology (statistics)

  • A widely cited prevalence estimate is ~1 per 40,000 live births. (lake2016leighsyndromeone pages 1-6, baldo2024acomprehensiveapproach pages 1-2, lim2022naturalhistorystudy pages 50-53)
  • Founder effects can produce much higher incidence in particular populations (e.g., LRPPRC in Saguenay–Lac-Saint-Jean; SUCLA2 in Faroe Islands) per compiled prevalence notes. (lim2022naturalhistorystudy pages 50-53)

9.2 Inheritance patterns

  • Mixed: autosomal recessive, maternal (mtDNA), X-linked—supported by expert-panel curated distribution and classic review descriptions. (lake2016leighsyndromeone pages 1-6, mccormick2023expertpanelcuration pages 9-10)

10. Diagnostics

10.1 Core clinical + imaging criteria

Modern LSS diagnostic approaches emphasize: - Compatible neurologic presentation (developmental delay/regression, epilepsy, movement disorder, etc.) - Neuroradiology: bilateral symmetric basal ganglia/brainstem lesions (T2 hyperintensities; CT hypodensities) - Biochemical support (lactate/pyruvate abnormalities) - Genetic confirmation increasingly required/central (baldo2024acomprehensiveapproach pages 1-2, baldo2024acomprehensiveapproach pages 2-4)

10.2 Biochemical and laboratory tests

Commonly used markers include: - Elevated lactate (serum and/or CSF) (lim2022naturalhistoryof pages 2-3) - Lactate/pyruvate ratio: L/P >20 highlighted as more specific in one diagnostic review (baldo2024acomprehensiveapproach pages 1-2) - Plasma amino acids (e.g., alanine elevation reflecting glycolytic shift) and urine organic acids/acylcarnitines as parallel first-tier studies to identify treatable etiologies faster. (baldo2024acomprehensiveapproach pages 1-2, baldo2024acomprehensiveapproach pages 2-4)

10.3 Genetic testing strategy

  • A diagnostic review proposes a pipeline adding rapid biochemical screening (amino acids, acylcarnitine, urinary organic acids) in parallel with genetic testing; in their cohort, this approach “characterized 80%” and enabled “specific intervention in 10% of confirmed cases.” (baldo2024acomprehensiveapproach pages 1-2)
  • Large cohorts show high genetic diagnostic yield (e.g., 82% in one natural-history cohort). (lim2022naturalhistoryof pages 2-3)

10.4 Visual evidence: diagnostic workflow

A diagnostic algorithm (flowchart) summarizing imaging criteria, biochemical screening, and genetic studies for LSS is presented in the Baldo et al. 2024 paper (Figure 1). (baldo2024acomprehensiveapproach media 389448a6)

11. Outcome/Prognosis

11.1 Survival and mortality (recent cohort statistics)

  • Japanese cohort (n=166): 24.1% deceased at follow-up; “Nearly 90% of deaths occurred by age 6.” Earlier onset (<6 months) predicted higher mortality; all neonatal-onset were deceased or bedridden. (lim2022naturalhistoryof pages 2-3)
  • Beijing cohort (n=209): genotype-specific outcomes; poorest outcomes (≤50% 3-year survival) included MT-ND5, MT-ATP6 m.8993T>C/m.9176T>C, SURF1, ALDH5A1, while treatable causes (ECHS1, SLC19A3) had 100% 3-year survival. (stenton2022leighsyndromea pages 1-1)

11.2 Prognostic factors

  • Age at onset is consistently prognostic (early onset worse). (lim2022naturalhistoryof pages 2-3)
  • Genotype is prognostic with strong defect-specific patterns. (stenton2022leighsyndromea pages 1-1)

12. Treatment

12.1 Standard of care (current real-world implementation)

There is no broadly curative therapy; management is typically supportive and multidisciplinary (neurology, metabolic genetics, nutrition, PT/OT/SLP) plus targeted interventions for treatable genetic subtypes when identified. Reviews and cohort data indicate widespread use of vitamin/cofactor supplementation in practice, though a natural history study observed no clear effect on overall course during follow-up. (lake2016leighsyndromeone pages 19-24, lim2022naturalhistoryof pages 2-3)

12.2 Genotype-targeted / treatable causes

Treatable etiologies highlighted in diagnostic reviews include: - SLC19A3 (biotin–thiamine-responsive basal ganglia disease; a Leigh(-like) mimic/overlap) - Valine pathway disorders (e.g., ECHS1, HIBCH) (baldo2024acomprehensiveapproach pages 2-4)

12.3 Recent developments (prioritizing 2023–2024)

Gene curation and trial readiness (2023): ClinGen Mito GCEP provided a curated gene list and refined phenotype criteria intended to streamline diagnosis and enable inclusive clinical trials. (mccormick2023expertpanelcuration pages 9-10)

Global patient registry (2023): registry infrastructure aims to support natural history understanding and facilitate clinical trial recruitment with global reach (nearly 70% outside US). (zilber2023leighsyndromeglobal pages 1-2, zilber2023leighsyndromeglobal pages 8-11)

Anesthesia safety signal (2023): volatile anesthetic toxicity shown in the Ndufs4−/− model suggests disease-stage dependence and potential neuroimmune modulation—important for perioperative risk management research. (spencer2023volatileanaesthetictoxicity pages 1-2)

12.4 Pharmacotherapy/experimental trials (ClinicalTrials.gov)

EPI-743 (vatiquinone) in Leigh syndrome (NCT01721733): Phase 2B randomized, placebo-controlled, double-blind trial in children (6–17 years), n=35, primary endpoint change in NPMDS over 6 months; completed (study completion 2015-05-31). (NCT01721733 chunk 1)

12.5 MAXO suggestions (treatments/actions)

  • Supportive mitochondrial disease management: MAXO terms not directly retrievable here; suggested mappings include supportive care, nutritional support, feeding tube placement, physical therapy/rehabilitation (consistent with registry “devices” and interventions). (zilber2023leighsyndromeglobal pages 8-11)
  • Genotype-guided vitamin therapy: thiamine/biotin supplementation for SLC19A3-related treatable disease. (baldo2024acomprehensiveapproach pages 2-4)

13. Prevention

13.1 Primary prevention

No population-level prevention exists for most LS causes. Prevention is primarily via genetic counseling, reproductive options, and avoidance of known iatrogenic stressors when possible.

13.2 Secondary/tertiary prevention

  • Earlier diagnosis via streamlined biochemical + genetic pipelines can enable prompt treatment for treatable mimics/overlaps and improve supportive management planning. (baldo2024acomprehensiveapproach pages 1-2, baldo2024acomprehensiveapproach pages 2-4)
  • Registry efforts aim to improve early recognition and trial readiness. (zilber2023leighsyndromeglobal pages 1-2)

14. Other Species / Natural Disease

Direct evidence for naturally occurring Leigh syndrome in non-human species was not retrieved in this run. (Not available from the gathered context.)

15. Model Organisms

15.1 Model landscape (2024 review)

A 2024 review summarizes LS disease models “from yeast to organoids,” including yeast biochemical models, invertebrates (Drosophila, C. elegans), zebrafish, mammalian models, and patient-derived iPSCs/organoids; it states that mutations in “more than 100 genes” can cause LS and emphasizes model selection based on the research question. (henke2024diseasemodelsof pages 2-5)

15.2 Widely used mammalian model: Ndufs4−/− mouse

  • Highlighted as a gold-standard model recapitulating LSS features in ClinGen scoring guidance and used extensively in mechanistic and therapy studies. (mccormick2023expertpanelcuration pages 9-10, lake2016leighsyndromeone pages 19-24)
  • Used to study volatile anesthetic toxicity (isoflurane) and neuroimmune modulation via CSF1R inhibition. (spencer2023volatileanaesthetictoxicity pages 1-2)

Embedded Summary Artifact

The following table consolidates key nomenclature and headline epidemiology/prognosis facts from the retrieved evidence:

Item type Value Notes Source (with PMID if available) URL Publication date
Identifier Leigh syndrome (OMIM 256000) Baldo & Vilarinho review explicitly states “Leigh Syndrome (OMIM 256000)”; classic synonym is subacute necrotizing encephalomyelopathy (lake2016leighsyndromeone pages 1-6, zilber2023leighsyndromeglobal pages 2-4) Baldo MS, Vilarinho L. Orphanet J Rare Dis. 2020; PMID not provided in gathered context https://doi.org/10.1186/s13023-020-1297-9 2020-01
Synonym Subacute necrotizing encephalomyelopathy Classical neuropathologic designation used for LS/LSS in reviews and ClinGen-oriented literature (lake2016leighsyndromeone pages 1-6, mccormick2023expertpanelcuration pages 9-10) Lake NJ et al. Ann Neurol. 2016; PMID not provided in gathered context https://doi.org/10.1002/ana.24551 2016-02
Synonym Leigh syndrome spectrum (LSS) Newer umbrella term encompassing classical Leigh syndrome and Leigh-like phenotypes; used in recent diagnostic and ClinGen frameworks (baldo2024acomprehensiveapproach pages 1-2, mccormick2023expertpanelcuration pages 9-10) Baldo MS et al. Diagnostics. 2024; PMID not provided in gathered context https://doi.org/10.3390/diagnostics14192133 2024-09
Identifier/Nomenclature ClinGen Mito GCEP curated 113 primary mitochondrial disease genes for LSS Expert-panel framework to standardize LSS definition and gene–disease relationships; 114 GDRs assessed (31 definitive, 38 moderate, 43 limited, 2 disputed) (mccormick2023expertpanelcuration pages 9-10, mccormick2023expertpanelcuration pages 4-5) McCormick E et al. Ann Neurol. 2023; PMID not provided in gathered context https://doi.org/10.1002/ana.26716 2023-08
Epidemiology Prevalence/birth prevalence ~1 per 40,000 live births Repeated across authoritative reviews and recent diagnostic review as the standard headline prevalence estimate (lake2016leighsyndromeone pages 1-6, baldo2024acomprehensiveapproach pages 1-2, lim2022naturalhistorystudy pages 50-53) Lake NJ et al. Ann Neurol. 2016; PMID not provided in gathered context https://doi.org/10.1002/ana.24551 2016-02
Epidemiology Higher-prevalence founder populations reported Examples include LRPPRC in Saguenay–Lac-Saint-Jean (~1:2000) and SUCLA2 in the Faroe Islands (~1:1700) (lim2022naturalhistorystudy pages 50-53) Lim AZ. Natural history thesis/report, 2022; PMID not provided in gathered context Not available in gathered context 2022
Epidemiology Most common pediatric manifestation of primary mitochondrial disease Leigh syndrome/LSS is consistently described as the most frequent pediatric mitochondrial neurodegenerative disorder (baldo2024acomprehensiveapproach pages 1-2, mccormick2023expertpanelcuration pages 9-10) Baldo MS et al. Diagnostics. 2024; PMID not provided in gathered context https://doi.org/10.3390/diagnostics14192133 2024-09
Prognosis Typical onset before age 2 years Onset generally by age 2 years; median age at onset 9 months in one natural-history cohort (lake2016leighsyndromeone pages 1-6, lim2022naturalhistoryof pages 2-3) Lim AZ et al. Ann Neurol. 2022; PMID not provided in gathered context https://doi.org/10.1002/ana.26260 2022-11
Prognosis Often rapidly progressive Authoritative review notes progression is often rapid, with classic severe pediatric course (lake2016leighsyndromeone pages 1-6) Lake NJ et al. Ann Neurol. 2016; PMID not provided in gathered context https://doi.org/10.1002/ana.24551 2016-02
Prognosis Typical historical outcome: death by ~3 years in severe early-onset disease Review summarizes classic expectation of death by age 3; more recent cohorts show genotype-specific variability and some longer survival (lake2016leighsyndromeone pages 1-6, stenton2022leighsyndromea pages 1-1) Lake NJ et al. Ann Neurol. 2016; PMID not provided in gathered context https://doi.org/10.1002/ana.24551 2016-02
Prognosis Nearly 90% of deaths occurred by age 6 in a Japanese cohort In 166 patients, early onset (<6 months) strongly worsened mortality; all neonatal-onset patients were deceased or bedridden (lim2022naturalhistoryof pages 2-3) Ogawa E et al. J Inherit Metab Dis. 2020; PMID not provided in gathered context https://doi.org/10.1002/jimd.12218 2020-02
Prognosis Genotype-specific 3-year survival differs substantially Poorest outcomes (≤50% 3-year survival) reported for MT-ND5, MT-ATP6 m.8993T>C/m.9176T>C, SURF1, ALDH5A1; treatable causes such as ECHS1 and SLC19A3 had 100% 3-year survival in the Beijing cohort (stenton2022leighsyndromea pages 1-1) Stenton SL et al. Ann Neurol. 2022; PMID not provided in gathered context https://doi.org/10.1002/ana.26313 2022-03
Prognosis Registry snapshot suggests substantial burden but some resilience Global registry (n=116) found high disease burden, relatively short time to diagnosis, generally good reported QoL, and caregivers reporting significant stress; ~70% lived outside the US (zilber2023leighsyndromeglobal pages 1-2, zilber2023leighsyndromeglobal pages 8-11, zilber2023leighsyndromeglobal pages 2-4) Zilber S et al. Orphanet J Rare Dis. 2023; PMID not provided in gathered context https://doi.org/10.1186/s13023-023-02886-0 2023-09

Table: This table summarizes core nomenclature, identifiers, and headline epidemiology/prognosis facts for Leigh syndrome/Leigh syndrome spectrum using only gathered evidence. It is useful as a compact reference for disease knowledge base population.

References (URLs and publication dates from retrieved sources)

  • Lake NJ et al. Annals of Neurology (2016-02). “Leigh syndrome: One disorder, more than 75 monogenic causes.” https://doi.org/10.1002/ana.24551 (lake2016leighsyndromeone pages 1-6, lake2016leighsyndromeone pages 19-24)
  • McCormick E et al. Annals of Neurology (2023-08). “Expert panel curation of 113 primary mitochondrial disease genes for the Leigh syndrome spectrum.” https://doi.org/10.1002/ana.26716 (mccormick2023expertpanelcuration pages 9-10, mccormick2023expertpanelcuration pages 4-5)
  • Baldo MS et al. Diagnostics (2024-09). “A Comprehensive Approach to the Diagnosis of Leigh Syndrome Spectrum.” https://doi.org/10.3390/diagnostics14192133 (baldo2024acomprehensiveapproach pages 1-2, baldo2024acomprehensiveapproach pages 2-4, baldo2024acomprehensiveapproach media 389448a6)
  • Lim AZ et al. Annals of Neurology (2022-11). “Natural History of Leigh Syndrome: A Study of Disease Burden and Progression.” https://doi.org/10.1002/ana.26260 (lim2022naturalhistoryof pages 2-3)
  • Stenton SL et al. Annals of Neurology (2022-03). “Leigh Syndrome: A Study of 209 Patients at the Beijing Children’s Hospital.” https://doi.org/10.1002/ana.26313 (stenton2022leighsyndromea pages 1-1)
  • Zilber S et al. Orphanet Journal of Rare Diseases (2023-09). “Leigh syndrome global patient registry: uniting patients and researchers worldwide.” https://doi.org/10.1186/s13023-023-02886-0 (zilber2023leighsyndromeglobal pages 1-2, zilber2023leighsyndromeglobal pages 8-11, zilber2023leighsyndromeglobal pages 2-4, zilber2023leighsyndromeglobal pages 11-12)
  • Spencer KA et al. British Journal of Anaesthesia (2023-11). “Volatile anaesthetic toxicity in the genetic mitochondrial disease Leigh syndrome.” https://doi.org/10.1016/j.bja.2023.08.009 (spencer2023volatileanaesthetictoxicity pages 1-2)
  • ClinicalTrials.gov: NCT01721733 (EPI-743/vatiquinone). First posted 2012; completed 2015. https://clinicaltrials.gov/study/NCT01721733 (NCT01721733 chunk 1)

References

  1. (lake2016leighsyndromeone pages 1-6): Nicole J. Lake, Alison G. Compton, Shamima Rahman, and David R. Thorburn. Leigh syndrome: one disorder, more than 75 monogenic causes. Annals of Neurology, 79:190-203, Feb 2016. URL: https://doi.org/10.1002/ana.24551, doi:10.1002/ana.24551. This article has 646 citations and is from a highest quality peer-reviewed journal.

  2. (baldo2024acomprehensiveapproach pages 1-2): Manuela Schubert Baldo, Luísa Azevedo, Margarida Paiva Coelho, Esmeralda Martins, and Laura Vilarinho. A comprehensive approach to the diagnosis of leigh syndrome spectrum. Diagnostics, 14:2133, Sep 2024. URL: https://doi.org/10.3390/diagnostics14192133, doi:10.3390/diagnostics14192133. This article has 3 citations.

  3. (mccormick2023expertpanelcuration pages 9-10): E. McCormick, Kierstin N. Keller, Julie Taylor, A. Coffey, Lishuang Shen, D. Krotoski, B. Harding, C. Alves, A. Ardissone, Renkui Bai, I.P. de Barcelos, E. Bertini, Krista K. Bluske, J. Christodoulou, Amanda R. Clause, W. Copeland, G. Diaz, D. Diodato, M. Dulik, G. Enns, A. Feigenbaum, C. Fratter, D. Ghezzi, A. Goldstein, A. Gropman, R. Haas, A. Karaa, M. Koenig, B. Monteleone, S. Parikh, B. P. Dueñas, Revathi Rajkumar, Ann Saada, R. Saneto, K. Sergeant, J. Shoffner, Conrad Smith, C. Stanley, Isabelle Thiffault, D. Thorburn, M. Walker, D. Wallace, L. Wong, Xiaowu Gai, Marni J. Falk, Z. Zolkipli-Cunningham, and S. Rahman. Expert panel curation of 113 primary mitochondrial disease genes for the leigh syndrome spectrum. Annals of Neurology, 94:696-712, Aug 2023. URL: https://doi.org/10.1002/ana.26716, doi:10.1002/ana.26716. This article has 61 citations and is from a highest quality peer-reviewed journal.

  4. (lim2022naturalhistoryof pages 2-3): Albert Z. Lim, Yi Shiau Ng, Alasdair Blain, Cecilia Jiminez‐Moreno, Charlotte L. Alston, Victoria Nesbitt, Louise Simmons, Saikat Santra, Evangeline Wassmer, Emma L. Blakely, Doug M. Turnbull, Robert W. Taylor, Gráinne S. Gorman, and Robert McFarland. Natural history of leigh syndrome: a study of disease burden and progression. Annals of Neurology, 91:117-130, Nov 2022. URL: https://doi.org/10.1002/ana.26260, doi:10.1002/ana.26260. This article has 50 citations and is from a highest quality peer-reviewed journal.

  5. (stenton2022leighsyndromea pages 1-1): Sarah L. Stenton, Ying Zou, Hua Cheng, Zhimei Liu, Junling Wang, Danmin Shen, Hong Jin, Changhong Ding, Xiaolu Tang, Suzhen Sun, Hong Han, Yanli Ma, Weihua Zhang, Ruifeng Jin, Hua Wang, Dan Sun, Jun Lan Lv, Holger Prokisch, and Fang Fang. Leigh syndrome: a study of 209 patients at the beijing children's hospital. Mar 2022. URL: https://doi.org/10.1002/ana.26313, doi:10.1002/ana.26313. This article has 44 citations and is from a highest quality peer-reviewed journal.

  6. (zilber2023leighsyndromeglobal pages 1-2): Sophia Zilber, Kasey Woleben, Simon C. Johnson, Carolina Fischinger Moura de Souza, Danielle Boyce, Kevin Freiert, Courtney Boggs, Souad Messahel, Melinda J. Burnworth, Titilola M. Afolabi, and Saima Kayani. Leigh syndrome global patient registry: uniting patients and researchers worldwide. Orphanet Journal of Rare Diseases, Sep 2023. URL: https://doi.org/10.1186/s13023-023-02886-0, doi:10.1186/s13023-023-02886-0. This article has 19 citations and is from a peer-reviewed journal.

  7. (zilber2023leighsyndromeglobal pages 8-11): Sophia Zilber, Kasey Woleben, Simon C. Johnson, Carolina Fischinger Moura de Souza, Danielle Boyce, Kevin Freiert, Courtney Boggs, Souad Messahel, Melinda J. Burnworth, Titilola M. Afolabi, and Saima Kayani. Leigh syndrome global patient registry: uniting patients and researchers worldwide. Orphanet Journal of Rare Diseases, Sep 2023. URL: https://doi.org/10.1186/s13023-023-02886-0, doi:10.1186/s13023-023-02886-0. This article has 19 citations and is from a peer-reviewed journal.

  8. (zilber2023leighsyndromeglobal pages 2-4): Sophia Zilber, Kasey Woleben, Simon C. Johnson, Carolina Fischinger Moura de Souza, Danielle Boyce, Kevin Freiert, Courtney Boggs, Souad Messahel, Melinda J. Burnworth, Titilola M. Afolabi, and Saima Kayani. Leigh syndrome global patient registry: uniting patients and researchers worldwide. Orphanet Journal of Rare Diseases, Sep 2023. URL: https://doi.org/10.1186/s13023-023-02886-0, doi:10.1186/s13023-023-02886-0. This article has 19 citations and is from a peer-reviewed journal.

  9. (zilber2023leighsyndromeglobal pages 11-12): Sophia Zilber, Kasey Woleben, Simon C. Johnson, Carolina Fischinger Moura de Souza, Danielle Boyce, Kevin Freiert, Courtney Boggs, Souad Messahel, Melinda J. Burnworth, Titilola M. Afolabi, and Saima Kayani. Leigh syndrome global patient registry: uniting patients and researchers worldwide. Orphanet Journal of Rare Diseases, Sep 2023. URL: https://doi.org/10.1186/s13023-023-02886-0, doi:10.1186/s13023-023-02886-0. This article has 19 citations and is from a peer-reviewed journal.

  10. (lake2016leighsyndromeone pages 19-24): Nicole J. Lake, Alison G. Compton, Shamima Rahman, and David R. Thorburn. Leigh syndrome: one disorder, more than 75 monogenic causes. Annals of Neurology, 79:190-203, Feb 2016. URL: https://doi.org/10.1002/ana.24551, doi:10.1002/ana.24551. This article has 646 citations and is from a highest quality peer-reviewed journal.

  11. (spencer2023volatileanaesthetictoxicity pages 1-2): Kira A. Spencer, Michael Mulholland, John Snell, Miranda Howe, Katerina James, Allison R. Hanaford, Philip G. Morgan, Margaret Sedensky, and Simon C. Johnson. Volatile anaesthetic toxicity in the genetic mitochondrial disease leigh syndrome. British Journal of Anaesthesia, 131:832-846, Nov 2023. URL: https://doi.org/10.1016/j.bja.2023.08.009, doi:10.1016/j.bja.2023.08.009. This article has 14 citations and is from a highest quality peer-reviewed journal.

  12. (mccormick2023expertpanelcuration pages 4-5): E. McCormick, Kierstin N. Keller, Julie Taylor, A. Coffey, Lishuang Shen, D. Krotoski, B. Harding, C. Alves, A. Ardissone, Renkui Bai, I.P. de Barcelos, E. Bertini, Krista K. Bluske, J. Christodoulou, Amanda R. Clause, W. Copeland, G. Diaz, D. Diodato, M. Dulik, G. Enns, A. Feigenbaum, C. Fratter, D. Ghezzi, A. Goldstein, A. Gropman, R. Haas, A. Karaa, M. Koenig, B. Monteleone, S. Parikh, B. P. Dueñas, Revathi Rajkumar, Ann Saada, R. Saneto, K. Sergeant, J. Shoffner, Conrad Smith, C. Stanley, Isabelle Thiffault, D. Thorburn, M. Walker, D. Wallace, L. Wong, Xiaowu Gai, Marni J. Falk, Z. Zolkipli-Cunningham, and S. Rahman. Expert panel curation of 113 primary mitochondrial disease genes for the leigh syndrome spectrum. Annals of Neurology, 94:696-712, Aug 2023. URL: https://doi.org/10.1002/ana.26716, doi:10.1002/ana.26716. This article has 61 citations and is from a highest quality peer-reviewed journal.

  13. (henke2024diseasemodelsof pages 2-5): Marie‐Thérèse Henke, Alessandro Prigione, and Markus Schuelke. Disease models of leigh syndrome: from yeast to organoids. Journal of Inherited Metabolic Disease, 47:1292-1321, Oct 2024. URL: https://doi.org/10.1002/jimd.12804, doi:10.1002/jimd.12804. This article has 15 citations and is from a peer-reviewed journal.

  14. (baldo2024acomprehensiveapproach pages 2-4): Manuela Schubert Baldo, Luísa Azevedo, Margarida Paiva Coelho, Esmeralda Martins, and Laura Vilarinho. A comprehensive approach to the diagnosis of leigh syndrome spectrum. Diagnostics, 14:2133, Sep 2024. URL: https://doi.org/10.3390/diagnostics14192133, doi:10.3390/diagnostics14192133. This article has 3 citations.

  15. (lim2022naturalhistorystudy pages 50-53): AZ Lim. Natural history study of childhood-onset mitochondrial disorders by using outcome measure assessments. Unknown journal, 2022.

  16. (baldo2024acomprehensiveapproach media 389448a6): Manuela Schubert Baldo, Luísa Azevedo, Margarida Paiva Coelho, Esmeralda Martins, and Laura Vilarinho. A comprehensive approach to the diagnosis of leigh syndrome spectrum. Diagnostics, 14:2133, Sep 2024. URL: https://doi.org/10.3390/diagnostics14192133, doi:10.3390/diagnostics14192133. This article has 3 citations.

  17. (NCT01721733 chunk 1): Safety and Efficacy Study of EPI-743 in Children With Leigh Syndrome. PTC Therapeutics. 2012. ClinicalTrials.gov Identifier: NCT01721733

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