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1
Inheritance
5
Pathophys.
9
Phenotypes
19
Pathograph
1
Genes
3
Treatments
1
Deep Research
👪

Inheritance

1
Autosomal recessive inheritance HP:0000007
Gyrate atrophy caused by OAT dysfunction follows autosomal recessive inheritance.
Autosomal recessive inheritance
Show evidence (2 references)
DOI:10.1002/prot.70134 SUPPORT Human Clinical
"Human OAT holds significant clinical and scientific interest because (i) its dysfunction causes gyrate atrophy (GA) of the choroid and retina, a rare autosomal recessive disease, and (ii) it is recognized as a potential target for chemotherapeutic drug development, being overexpressed in some..."
This review directly states the autosomal recessive inheritance of gyrate atrophy due to OAT dysfunction.
PMID:33068755 SUPPORT Human Clinical
"Gyrate Atrophy (GA) of the choroid and retina (MIM# 258870) is an autosomal recessive disorder due to mutations of the OAT gene encoding ornithine-delta-aminotransferase (OAT), associated with progressive retinal deterioration and blindness."
Comprehensive review confirms autosomal recessive inheritance of gyrate atrophy due to OAT gene mutations.

Pathophysiology

5
OAT deficiency and impaired ornithine transamination
OAT deficiency disrupts mitochondrial matrix, PLP-dependent ornithine transamination, blocking L-ornithine catabolism to glutamate semialdehyde/P5C and glutamate and causing the metabolic defect underlying gyrate atrophy.
OAT link
ornithine metabolic process link ↓ DECREASED L-ornithine catabolic process link ↓ DECREASED L-proline biosynthetic process link ↓ DECREASED
L-ornithine transaminase activity link ↓ DECREASED
mitochondrial matrix link
Show evidence (3 references)
DOI:10.1002/prot.70134 SUPPORT In Vitro
"Human ornithine aminotransferase (hOAT) is a mitochondrial matrix pyridoxal‐5′‐phosphate enzyme (PLP) that catalyzes the reversible transfer of the δ‐amino group of L‐ornithine (L‐Orn) to α‐ketoglutarate (α‐KG) yielding glutamate‐5‐semialdehyde (GSA) and glutamate."
This directly supports the primary enzymatic function disrupted in OAT deficiency.
PMID:33068755 SUPPORT Human Clinical
"OAT is mainly involved in ornithine catabolism in adults, thus explaining the hyperornithinemia as hallmark of the disease."
Confirms the role of OAT in ornithine catabolism and its link to the disease hallmark of hyperornithinemia.
PMID:34395527 SUPPORT In Vitro
"The deficit of hOAT leads to a 10-to-15 fold increase in the plasmatic L-Orn concentration, along with a small reduction in the levels of glutamate, glutamine, lysine and creatine"
Review text supports elevated L-ornithine and secondary reductions in glutamate, lysine, and creatine downstream of hOAT deficiency.
Hyperornithinemia
Loss of ornithine aminotransferase activity causes marked plasma ornithine accumulation, the central biochemical lesion in the disease.
ornithine metabolic process link ↑ INCREASED
Show evidence (2 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"All patients had high plasma ornithine levels at the time of diagnosis, and they were all started on an arginine-restricted diet."
This directly supports hyperornithinemia as the key metabolic intermediate between OAT deficiency and retinal degeneration.
PMID:10655512 SUPPORT Model Organism
"Deficiency of ornithine-delta-aminotransferase (OAT) in humans results in gyrate atrophy of the choroid and retina (GA), an autosomal recessive disorder characterized by ornithine accumulation and a progressive chorioretinal degeneration of unknown pathogenesis."
Mouse model study confirms ornithine accumulation as the characteristic biochemical feature of OAT deficiency.
Progressive chorioretinal degeneration
The downstream ophthalmologic disease causes progressive retinal and choroidal damage that drives nyctalopia, visual field constriction, and visual decline.
retinal pigment epithelial cell link
Show evidence (3 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"The patients primarily present with progressive ophthalmological findings."
This cohort study directly supports progressive ophthalmologic degeneration as the key downstream disease process.
PMID:10655512 SUPPORT Model Organism
"an arginine-restricted diet substantially reduces plasma ornithine levels and completely prevents retinal degeneration in Oat(-/-)"
Mouse model demonstrates that reducing ornithine accumulation prevents retinal degeneration, confirming that hyperornithinemia drives chorioretinal damage.
PMID:8675686 SUPPORT Model Organism
"Our results indicate that retinal pigment epithelial cells are the initial site of insult in GA and that the OAT-deficient mouse is an excellent animal model of GA in human patients."
Mouse-model evidence identifies RPE cells as the initial cellular site of injury in gyrate atrophy.
Retinal pigment epithelial cell injury
Retinal pigment epithelial cells are an early site of insult in the hyperornithinemic OAT-deficient retina, preceding progressive photoreceptor disorganization and cell loss.
retinal pigment epithelial cell link
Show evidence (2 references)
PMID:8675686 SUPPORT Model Organism
"At 2 mo, the retinal pigment epithelium is histologically normal, but electron microscopy reveals sporadic degeneration of scattered pigment epithelial cells."
Mouse-model evidence shows early RPE ultrastructural injury in OAT deficiency.
PMID:8675686 SUPPORT Model Organism
"Our results indicate that retinal pigment epithelial cells are the initial site of insult in GA and that the OAT-deficient mouse is an excellent animal model of GA in human patients."
The study identifies RPE cells as the initial injury site in the disease model.
Secondary amino acid and creatine depletion
The OAT metabolic lesion is accompanied by reduced glutamate, lysine, and creatine pools; low cerebral creatine provides a plausible biochemical link to extraocular neurologic and neuromuscular manifestations in a subset of patients.
creatine metabolic process link ↓ DECREASED
Show evidence (2 references)
PMID:34395527 SUPPORT In Vitro
"The deficit of hOAT leads to a 10-to-15 fold increase in the plasmatic L-Orn concentration, along with a small reduction in the levels of glutamate, glutamine, lysine and creatine"
Review text supports secondary reductions in amino-acid and creatine pools downstream of hOAT deficiency.
PMID:32418451 SUPPORT Human Clinical
"the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine."
Case-report abstract supports low cerebral creatine alongside extraocular neurologic and neuromuscular manifestations.

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for ornithine aminotransferase deficiency 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

9
Eye 5
Nyctalopia Nyctalopia (HP:0000662)
Show evidence (2 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"Night blindness, cataracts, vision loss, and impaired cognitive functions can be seen."
This directly supports nyctalopia as part of the core ophthalmologic phenotype.
PMID:34894815 SUPPORT Human Clinical
"Patients usually present with night blindness that starts in the first decade of life followed by visual field constriction and eventually diminution of the central visual acuity and blindness."
Review confirms night blindness as the presenting symptom beginning in the first decade of life.
Cataract Cataract (HP:0000518)
Show evidence (2 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"Night blindness, cataracts, vision loss, and impaired cognitive functions can be seen."
This directly supports cataract as a common ophthalmologic manifestation.
PMID:34894815 SUPPORT Human Clinical
"leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes."
Review confirms cataract as one of the characteristic ophthalmic manifestations.
Visual loss Progressive visual loss (HP:0000529)
Course: PROGRESSIVE
Show evidence (2 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"Night blindness, cataracts, vision loss, and impaired cognitive functions can be seen."
This directly supports progressive visual loss as a core phenotype.
PMID:34340878 SUPPORT Human Clinical
"GACR is characterised by vision decline in early life eventually leading to complete blindness, and high plasma ornithine levels."
Systematic review confirms vision decline progressing to complete blindness.
Myopia Myopia (HP:0000545)
Show evidence (2 references)
PMID:34894815 SUPPORT Human Clinical
"leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes."
Review identifies myopia as one of the characteristic ophthalmic manifestations of gyrate atrophy.
PMID:34395527 SUPPORT In Vitro
"Patients develop myopia during childhood, and show a progressive decrease in visual acuity from the 2° to the 3° decade leading to blindness within the 5° decade"
Full-text review confirms childhood-onset myopia as a typical feature.
Constriction of peripheral visual field Constriction of peripheral visual field (HP:0001133)
Course: PROGRESSIVE
Show evidence (1 reference)
PMID:34894815 SUPPORT Human Clinical
"Patients usually present with night blindness that starts in the first decade of life followed by visual field constriction and eventually diminution of the central visual acuity and blindness."
Review describes visual field constriction as part of the progressive ophthalmologic course.
Musculoskeletal 1
Muscle weakness Muscle weakness (HP:0001324)
Show evidence (1 reference)
PMID:32418451 SUPPORT Human Clinical
"the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine."
Case report identifies muscle weakness as a clinical manifestation associated with gyrate atrophy and hyperornithinemia.
Nervous System 1
Cognitive impairment Cognitive impairment (HP:0100543)
Show evidence (2 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"Night blindness, cataracts, vision loss, and impaired cognitive functions can be seen."
This directly supports cognitive impairment as part of the clinical spectrum of gyrate atrophy due to OAT deficiency.
PMID:34395527 PARTIAL In Vitro
"In most GA patients cognition is unaffected"
This full-text review notes that cognition is unaffected in most patients, indicating cognitive impairment is a variable rather than universal feature.
Other 2
Chorioretinal atrophy Chorioretinal atrophy (HP:0000533)
Course: PROGRESSIVE
Show evidence (2 references)
PMID:34894815 SUPPORT Human Clinical
"leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes."
Review identifies progressive chorioretinal atrophy as a characteristic ophthalmic manifestation.
PMID:33068755 SUPPORT Human Clinical
"Gyrate Atrophy (GA) of the choroid and retina (MIM# 258870) is an autosomal recessive disorder due to mutations of the OAT gene encoding ornithine-delta-aminotransferase (OAT), associated with progressive retinal deterioration and blindness."
Confirms progressive retinal deterioration as a defining feature.
Hyperornithinemia Hyperornithinemia (HP:0012026)
Show evidence (2 references)
PMID:33068755 SUPPORT Human Clinical
"OAT is mainly involved in ornithine catabolism in adults, thus explaining the hyperornithinemia as hallmark of the disease."
Review directly identifies hyperornithinemia as the hallmark of the disease.
PMID:34894815 SUPPORT Human Clinical
"Gyrate atrophy (GA) of the choroid and retina is a rare autosomal recessive genetic condition characterized by elevation of the plasma level of the amino acid ornithine due to deficiency of the enzyme ornithine ketoacid aminotransferase."
Review confirms elevated plasma ornithine as the defining biochemical feature.
🧬

Genetic Associations

1
OAT (Loss of function mutation)
Show evidence (3 references)
PMID:34395527 SUPPORT In Vitro
"The deficit of human ornithine aminotransferase (hOAT) is responsible for gyrate atrophy (GA), a rare recessive inherited disorder."
This directly supports OAT deficiency as the causal genetic lesion.
PMID:34340878 SUPPORT Human Clinical
"Gyrate atrophy of the choroid and retina (GACR) is a rare inborn error of amino acid metabolism caused by bi-allelic variations in OAT."
Systematic review confirms bi-allelic OAT mutations as the genetic cause.
"OAT | HGNC:8091 | ornithine aminotransferase deficiency | MONDO:0009796 | AR | Definitive"
ClinGen classifies the OAT-ornithine aminotransferase deficiency gene-disease relationship as definitive with autosomal recessive inheritance.
💊

Treatments

3
Arginine-restricted diet
Action: dietary intervention MAXO:0000088
Dietary arginine restriction is used to improve metabolic control and lower plasma ornithine burden.
Mechanism Target:
INHIBITS Hyperornithinemia — Arginine or protein restriction lowers ornithine burden, targeting the central hyperornithinemia node upstream of retinal degeneration.
Show evidence (2 references)
PMID:34340878 SUPPORT Human Clinical
"Protein-restricted diets lowered ornithine levels ranging from 16.0-91.2%."
Systematic review directly supports dietary protein or arginine restriction reducing the hyperornithinemia treatment target.
PMID:10655512 SUPPORT Model Organism
"an arginine-restricted diet substantially reduces plasma ornithine levels and completely prevents retinal degeneration in Oat(-/-)"
Oat-deficient mouse data support arginine restriction lowering plasma ornithine and preventing retinal degeneration.
Target Phenotypes: Hyperornithinemia
Show evidence (3 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"An arginine-restricted diet is combined with supplementation with pyridoxine, lysine, proline, or creatine to improve metabolic control."
This directly supports arginine restriction as the core disease-specific treatment strategy.
PMID:34340878 SUPPORT Human Clinical
"Protein-restricted diets lowered ornithine levels ranging from 16.0-91.2%."
Systematic review quantifies the effectiveness of protein-restricted diets in lowering ornithine levels.
PMID:10655512 SUPPORT Model Organism
"an arginine-restricted diet substantially reduces plasma ornithine levels and completely prevents retinal degeneration in Oat(-/-)"
Mouse model demonstrates that arginine-restricted diet prevents retinal degeneration by reducing ornithine accumulation.
Pyridoxine supplementation
Action: Pharmacotherapy NCIT:C15986
Agent: pyridoxine
Pyridoxine is used as adjunctive therapy in an attempt to improve metabolic control in some patients, although responsiveness is mutation-dependent and not universal. Related supplementation regimens may also include lysine, proline, or creatine in combination with arginine restriction.
Mechanism Target:
MODULATES Hyperornithinemia — Pyridoxine can reduce ornithine levels in responsive OAT variants, so it is modeled as variant-dependent modulation of the hyperornithinemia node.
Show evidence (1 reference)
PMID:34340878 SUPPORT Human Clinical
"Based primarily on case reports ornithine levels can be reduced by using a protein restricted diet, pyridoxine supplementation (variation-dependent) and/or lysine supplementation."
Systematic review supports variant-dependent ornithine reduction with pyridoxine supplementation.
Target Phenotypes: Hyperornithinemia
Show evidence (2 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"An arginine-restricted diet is combined with supplementation with pyridoxine, lysine, proline, or creatine to improve metabolic control."
This directly supports pyridoxine supplementation as part of the standard metabolic management regimen.
PMID:34340878 SUPPORT Human Clinical
"Pyridoxine responsiveness was reported in 30% of included mutations."
Systematic review reports that pyridoxine responsiveness is mutation-dependent and observed in about 30% of mutations.
Adjunctive lysine, proline, and creatine supplementation
Action: Pharmacotherapy NCIT:C15986
Agent: L-lysine L-proline creatine
Lysine, proline, or creatine supplementation may be combined with arginine restriction and pyridoxine to improve metabolic control; lysine has reported ornithine-lowering effects in case-based treatment literature, while creatine supplementation is biologically aligned with reported low cerebral creatine.
Mechanism Target:
MODULATES Hyperornithinemia — Lysine supplementation is reported with ornithine reduction in case-based treatment literature.
Show evidence (1 reference)
PMID:34340878 SUPPORT Human Clinical
"Based primarily on case reports ornithine levels can be reduced by using a protein restricted diet, pyridoxine supplementation (variation-dependent) and/or lysine supplementation."
Systematic review supports lysine supplementation as an ornithine-lowering adjunct in reported cases.
MODULATES Secondary amino acid and creatine depletion — Creatine supplementation targets the reported low-creatine component of the secondary biochemical imbalance.
Show evidence (1 reference)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"An arginine-restricted diet is combined with supplementation with pyridoxine, lysine, proline, or creatine to improve metabolic control."
Cohort report supports creatine and related supplementation as part of metabolic management.
Target Phenotypes: Hyperornithinemia Cognitive impairment Muscle weakness
Show evidence (2 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"An arginine-restricted diet is combined with supplementation with pyridoxine, lysine, proline, or creatine to improve metabolic control."
Cohort report directly lists lysine, proline, and creatine supplementation as adjunctive metabolic-management options.
PMID:34340878 SUPPORT Human Clinical
"Based primarily on case reports ornithine levels can be reduced by using a protein restricted diet, pyridoxine supplementation (variation-dependent) and/or lysine supplementation."
Systematic review supports lysine supplementation as an adjunctive ornithine-lowering treatment.
🔬

Biochemical Markers

2
Plasma ornithine (INCREASED)
Context: Elevated plasma ornithine is the core biochemical hallmark of the disorder, with levels typically elevated 10- to 15-fold above normal.
Pathograph Readouts
Readout Of Hyperornithinemia Positive Diagnostic
Elevated plasma L-ornithine directly reports the hyperornithinemia caused by impaired OAT-mediated ornithine catabolism.
Show evidence (2 references)
DOI:10.1186/s13023-026-04265-x SUPPORT Human Clinical
"All patients had high plasma ornithine levels at the time of diagnosis, and they were all started on an arginine-restricted diet."
This directly supports hyperornithinemia as the defining biochemical abnormality.
PMID:34395527 SUPPORT In Vitro
"The deficit of hOAT leads to a 10-to-15 fold increase in the plasmatic L-Orn concentration, along with a small reduction in the levels of glutamate, glutamine, lysine and creatine"
Full-text review quantifies the magnitude of ornithine elevation and notes associated reductions in glutamate, glutamine, lysine, and creatine.
Cerebral creatine (DECREASED)
Context: Low cerebral creatine has been reported with extraocular neurologic and neuromuscular manifestations in OAT deficiency and reflects secondary amino-acid/creatine metabolic imbalance.
Pathograph Readouts
Readout Of Secondary amino acid and creatine depletion Negative Diagnostic
Low cerebral creatine reports the secondary creatine depletion node that may contribute to extraocular neurologic and neuromuscular features.
Show evidence (1 reference)
PMID:32418451 SUPPORT Human Clinical
"the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine."
Case-report abstract supports low cerebral creatine as a biochemical finding in OAT deficiency with extraocular manifestations.
{ }

Source YAML

click to show
name: ornithine aminotransferase deficiency
creation_date: "2026-04-15T17:35:00Z"
updated_date: "2026-05-19T17:53:57Z"
description: >-
  Ornithine aminotransferase deficiency is a rare autosomal recessive amino acid
  metabolism disorder caused by OAT dysfunction and classically presenting as
  gyrate atrophy of the choroid and retina with hyperornithinemia and
  progressive ophthalmologic decline.
category: Mendelian
parents:
- hereditary disease
disease_term:
  preferred_term: ornithine aminotransferase deficiency
  term:
    id: MONDO:0009796
    label: ornithine aminotransferase deficiency
synonyms:
- gyrate atrophy of the choroid and retina
inheritance:
- name: Autosomal recessive inheritance
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  description: >-
    Gyrate atrophy caused by OAT dysfunction follows autosomal recessive
    inheritance.
  evidence:
  - reference: DOI:10.1002/prot.70134
    reference_title: "Current Insight into Human Ornithine Aminotransferase: A Review"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Human OAT holds significant clinical and scientific interest because (i) its dysfunction causes gyrate atrophy (GA) of the choroid and retina, a rare autosomal recessive disease, and (ii) it is recognized as a potential target for chemotherapeutic drug development, being overexpressed in some types of cancer.
    explanation: >-
      This review directly states the autosomal recessive inheritance of gyrate
      atrophy due to OAT dysfunction.
  - reference: PMID:33068755
    reference_title: "Deficit of human ornithine aminotransferase in gyrate atrophy: Molecular, cellular, and clinical aspects."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Gyrate Atrophy (GA) of the choroid and retina (MIM# 258870) is an autosomal recessive disorder due to mutations of the OAT gene encoding ornithine-delta-aminotransferase (OAT), associated with progressive retinal deterioration and blindness.
    explanation: >-
      Comprehensive review confirms autosomal recessive inheritance of gyrate
      atrophy due to OAT gene mutations.
pathophysiology:
- name: OAT deficiency and impaired ornithine transamination
  description: >-
    OAT deficiency disrupts mitochondrial matrix, PLP-dependent ornithine
    transamination, blocking L-ornithine catabolism to glutamate
    semialdehyde/P5C and glutamate and causing the metabolic defect underlying
    gyrate atrophy.
  genes:
  - preferred_term: OAT
    term:
      id: hgnc:8091
      label: OAT
  biological_processes:
  - preferred_term: ornithine metabolic process
    term:
      id: GO:0006591
      label: ornithine metabolic process
    modifier: DECREASED
  - preferred_term: L-ornithine catabolic process
    term:
      id: GO:0006593
      label: L-ornithine catabolic process
    modifier: DECREASED
  - preferred_term: L-proline biosynthetic process
    term:
      id: GO:0055129
      label: L-proline biosynthetic process
    modifier: DECREASED
  molecular_functions:
  - preferred_term: L-ornithine transaminase activity
    term:
      id: GO:0004587
      label: L-ornithine transaminase activity
    modifier: DECREASED
  locations:
  - preferred_term: mitochondrial matrix
    term:
      id: GO:0005759
      label: mitochondrial matrix
  chemical_entities:
  - preferred_term: L-ornithine
    term:
      id: CHEBI:15729
      label: L-ornithine
    modifier: INCREASED
  - preferred_term: L-glutamic acid
    term:
      id: CHEBI:16015
      label: L-glutamic acid
    modifier: DECREASED
  - preferred_term: L-lysine
    term:
      id: CHEBI:18019
      label: L-lysine
    modifier: DECREASED
  - preferred_term: creatine
    term:
      id: CHEBI:16919
      label: creatine
    modifier: DECREASED
  evidence:
  - reference: DOI:10.1002/prot.70134
    reference_title: "Current Insight into Human Ornithine Aminotransferase: A Review"
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Human ornithine aminotransferase (hOAT) is a mitochondrial matrix pyridoxal‐5′‐phosphate enzyme (PLP) that catalyzes the reversible transfer of the δ‐amino group of L‐ornithine (L‐Orn) to α‐ketoglutarate (α‐KG) yielding glutamate‐5‐semialdehyde (GSA) and glutamate.
    explanation: >-
      This directly supports the primary enzymatic function disrupted in OAT
      deficiency.
  - reference: PMID:33068755
    reference_title: "Deficit of human ornithine aminotransferase in gyrate atrophy: Molecular, cellular, and clinical aspects."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OAT is mainly involved in ornithine catabolism in adults, thus explaining the hyperornithinemia as hallmark of the disease.
    explanation: >-
      Confirms the role of OAT in ornithine catabolism and its link to the
      disease hallmark of hyperornithinemia.
  - reference: PMID:34395527
    reference_title: "Molecular and Cellular Studies Reveal Folding Defects of Human Ornithine Aminotransferase Variants Associated With Gyrate Atrophy of the Choroid and Retina."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      The deficit of hOAT leads to a 10-to-15 fold increase in the plasmatic L-Orn concentration, along with a small reduction in the levels of glutamate, glutamine, lysine and creatine
    explanation: >-
      Review text supports elevated L-ornithine and secondary reductions in
      glutamate, lysine, and creatine downstream of hOAT deficiency.
  downstream:
  - target: Hyperornithinemia
    description: Loss of OAT activity causes elevated plasma ornithine.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:33068755
      reference_title: "Deficit of human ornithine aminotransferase in gyrate atrophy: Molecular, cellular, and clinical aspects."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        OAT is mainly involved in ornithine catabolism in adults, thus
        explaining the hyperornithinemia as hallmark of the disease.
      explanation: >-
        Human review directly links loss of OAT-mediated ornithine catabolism
        to hyperornithinemia.
  - target: Secondary amino acid and creatine depletion
    description: >-
      OAT deficiency is associated with reduced glutamate, lysine, and creatine
      pools, including low cerebral creatine in some affected patients.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:34395527
      reference_title: "Molecular and Cellular Studies Reveal Folding Defects of Human Ornithine Aminotransferase Variants Associated With Gyrate Atrophy of the Choroid and Retina."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        The deficit of hOAT leads to a 10-to-15 fold increase in the plasmatic L-Orn concentration, along with a small reduction in the levels of glutamate, glutamine, lysine and creatine
      explanation: >-
        Review text links hOAT deficit to secondary reductions in amino-acid
        and creatine pools.
- name: Hyperornithinemia
  description: >-
    Loss of ornithine aminotransferase activity causes marked plasma ornithine
    accumulation, the central biochemical lesion in the disease.
  biological_processes:
  - preferred_term: ornithine metabolic process
    term:
      id: GO:0006591
      label: ornithine metabolic process
    modifier: INCREASED
  chemical_entities:
  - preferred_term: L-ornithine
    term:
      id: CHEBI:15729
      label: L-ornithine
    modifier: INCREASED
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      All patients had high plasma ornithine levels at the time of diagnosis, and they were all started on an arginine-restricted diet.
    explanation: >-
      This directly supports hyperornithinemia as the key metabolic
      intermediate between OAT deficiency and retinal degeneration.
  - reference: PMID:10655512
    reference_title: "Correction of ornithine accumulation prevents retinal degeneration in a mouse model of gyrate atrophy of the choroid and retina."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Deficiency of ornithine-delta-aminotransferase (OAT) in humans results in gyrate atrophy of the choroid and retina (GA), an autosomal recessive disorder characterized by ornithine accumulation and a progressive chorioretinal degeneration of unknown pathogenesis.
    explanation: >-
      Mouse model study confirms ornithine accumulation as the characteristic
      biochemical feature of OAT deficiency.
  downstream:
  - target: Progressive chorioretinal degeneration
    description: Sustained hyperornithinemia drives the retinal degenerative process.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:10655512
      reference_title: "Correction of ornithine accumulation prevents retinal degeneration in a mouse model of gyrate atrophy of the choroid and retina."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        This result indicates that ornithine accumulation is a necessary factor
        in the pathophysiology of the retinal degeneration in GA
      explanation: >-
        Oat-deficient mouse data support ornithine accumulation as necessary for
        retinal degeneration.
    - reference: PMID:34894815
      reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Accumulation of ornithine occurs in various body tissues but leads
        primarily to characteristic ophthalmic manifestations including myopia,
        cataract, progressive chorioretinal atrophy, and macular changes.
      explanation: >-
        Human clinical review connects ornithine accumulation to the
        characteristic ophthalmic manifestations.
  - target: Retinal pigment epithelial cell injury
    description: >-
      Chronic hyperornithinemia first injures retinal pigment epithelial cells
      in OAT-deficient mouse retina.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:8675686
      reference_title: "A mouse model of gyrate atrophy of the choroid and retina. Early retinal pigment epithelium damage and progressive retinal degeneration."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Like human GA patients, adult OAT-deficient mice exhibit chronic hyperornithinemia to levels 10-15-fold above normal and massive ornithinuria. Slowly progressive retinal degeneration is reflected by a gradual decline in electroretinogram amplitudes over the first 12 mo of life. At 2 mo, the retinal pigment epithelium is histologically normal, but electron microscopy reveals sporadic degeneration of scattered pigment epithelial cells.
      explanation: >-
        OAT-deficient mouse data link chronic hyperornithinemia to early RPE
        injury before progressive retinal degeneration.
  - target: Plasma ornithine
    description: Hyperornithinemia is measured as elevated plasma ornithine.
    causal_link_type: DIRECT
    evidence:
    - reference: DOI:10.1186/s13023-026-04265-x
      reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        All patients had high plasma ornithine levels at the time of diagnosis,
        and they were all started on an arginine-restricted diet.
      explanation: >-
        Cohort evidence directly supports elevated plasma ornithine as the
        measured biochemical expression of hyperornithinemia.
  - target: Cataract
    description: Ornithine accumulation contributes to cataract as part of the ocular disease.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:34894815
      reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Accumulation of ornithine occurs in various body tissues but leads
        primarily to characteristic ophthalmic manifestations including myopia,
        cataract, progressive chorioretinal atrophy, and macular changes.
      explanation: >-
        Review lists cataract among the characteristic ophthalmic manifestations
        associated with ornithine accumulation.
  - target: Myopia
    description: Ornithine accumulation is associated with childhood myopia as an early ocular feature.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:34894815
      reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Accumulation of ornithine occurs in various body tissues but leads
        primarily to characteristic ophthalmic manifestations including myopia,
        cataract, progressive chorioretinal atrophy, and macular changes.
      explanation: >-
        Review links tissue ornithine accumulation to myopia and other
        ophthalmic manifestations.
- name: Progressive chorioretinal degeneration
  description: >-
    The downstream ophthalmologic disease causes progressive retinal and choroidal
    damage that drives nyctalopia, visual field constriction, and visual decline.
  cell_types:
  - preferred_term: retinal pigment epithelial cell
    term:
      id: CL:0002586
      label: retinal pigment epithelial cell
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The patients primarily present with progressive ophthalmological findings.
    explanation: >-
      This cohort study directly supports progressive ophthalmologic degeneration
      as the key downstream disease process.
  - reference: PMID:10655512
    reference_title: "Correction of ornithine accumulation prevents retinal degeneration in a mouse model of gyrate atrophy of the choroid and retina."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      an arginine-restricted diet substantially reduces plasma ornithine levels and completely prevents retinal degeneration in Oat(-/-)
    explanation: >-
      Mouse model demonstrates that reducing ornithine accumulation prevents
      retinal degeneration, confirming that hyperornithinemia drives
      chorioretinal damage.
  - reference: PMID:8675686
    reference_title: "A mouse model of gyrate atrophy of the choroid and retina. Early retinal pigment epithelium damage and progressive retinal degeneration."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Our results indicate that retinal pigment epithelial cells are the initial site of insult in GA and that the OAT-deficient mouse is an excellent animal model of GA in human patients.
    explanation: >-
      Mouse-model evidence identifies RPE cells as the initial cellular site of
      injury in gyrate atrophy.
  downstream:
  - target: Nyctalopia
    description: Chorioretinal degeneration leads to early night blindness.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:34894815
      reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Patients usually present with night blindness that starts in the first
        decade of life followed by visual field constriction and eventually
        diminution of the central visual acuity and blindness.
      explanation: >-
        Review describes night blindness as the first manifestation in the
        progressive ophthalmologic sequence.
  - target: Chorioretinal atrophy
    description: Progressive retinal and choroidal degeneration manifests as chorioretinal atrophy.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:34894815
      reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Accumulation of ornithine occurs in various body tissues but leads
        primarily to characteristic ophthalmic manifestations including myopia,
        cataract, progressive chorioretinal atrophy, and macular changes.
      explanation: >-
        Review identifies progressive chorioretinal atrophy as a characteristic
        ophthalmic manifestation of gyrate atrophy.
  - target: Constriction of peripheral visual field
    description: Peripheral retinal degeneration causes progressive visual field constriction.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:34894815
      reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Patients usually present with night blindness that starts in the first
        decade of life followed by visual field constriction and eventually
        diminution of the central visual acuity and blindness.
      explanation: >-
        Review places visual field constriction after night blindness in the
        progressive ophthalmologic course.
  - target: Visual loss
    description: Ongoing retinal degeneration causes progressive visual loss.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:34894815
      reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Patients usually present with night blindness that starts in the first
        decade of life followed by visual field constriction and eventually
        diminution of the central visual acuity and blindness.
      explanation: >-
        Review supports progressive loss of central visual acuity and blindness
        as downstream outcomes of ocular degeneration.
- name: Retinal pigment epithelial cell injury
  description: >-
    Retinal pigment epithelial cells are an early site of insult in the
    hyperornithinemic OAT-deficient retina, preceding progressive photoreceptor
    disorganization and cell loss.
  cell_types:
  - preferred_term: retinal pigment epithelial cell
    term:
      id: CL:0002586
      label: retinal pigment epithelial cell
  evidence:
  - reference: PMID:8675686
    reference_title: "A mouse model of gyrate atrophy of the choroid and retina. Early retinal pigment epithelium damage and progressive retinal degeneration."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      At 2 mo, the retinal pigment epithelium is histologically normal, but electron microscopy reveals sporadic degeneration of scattered pigment epithelial cells.
    explanation: >-
      Mouse-model evidence shows early RPE ultrastructural injury in OAT
      deficiency.
  - reference: PMID:8675686
    reference_title: "A mouse model of gyrate atrophy of the choroid and retina. Early retinal pigment epithelium damage and progressive retinal degeneration."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      Our results indicate that retinal pigment epithelial cells are the initial site of insult in GA and that the OAT-deficient mouse is an excellent animal model of GA in human patients.
    explanation: >-
      The study identifies RPE cells as the initial injury site in the disease
      model.
  downstream:
  - target: Progressive chorioretinal degeneration
    description: Early RPE injury progresses to broader retinal degeneration and photoreceptor cell loss.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - photoreceptor outer segment disorganization
    - cumulative photoreceptor cell loss
    evidence:
    - reference: PMID:8675686
      reference_title: "A mouse model of gyrate atrophy of the choroid and retina. Early retinal pigment epithelium damage and progressive retinal degeneration."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        Although morphologically normal at 2 mo, the photo-receptor outer segments become highly disorganized and shortened to 60% of control length by 10 mo. Additionally, there is cumulative loss of the photoreceptor cells, which reaches 33% by 10 mo and is most pronounced in the central region of the retina.
      explanation: >-
        Mouse-model evidence places photoreceptor disorganization and cell loss
        downstream of early RPE injury.
- name: Secondary amino acid and creatine depletion
  description: >-
    The OAT metabolic lesion is accompanied by reduced glutamate, lysine, and
    creatine pools; low cerebral creatine provides a plausible biochemical link
    to extraocular neurologic and neuromuscular manifestations in a subset of
    patients.
  biological_processes:
  - preferred_term: creatine metabolic process
    term:
      id: GO:0006600
      label: creatine metabolic process
    modifier: DECREASED
  chemical_entities:
  - preferred_term: creatine
    term:
      id: CHEBI:16919
      label: creatine
    modifier: DECREASED
  - preferred_term: L-glutamic acid
    term:
      id: CHEBI:16015
      label: L-glutamic acid
    modifier: DECREASED
  - preferred_term: L-lysine
    term:
      id: CHEBI:18019
      label: L-lysine
    modifier: DECREASED
  evidence:
  - reference: PMID:34395527
    reference_title: "Molecular and Cellular Studies Reveal Folding Defects of Human Ornithine Aminotransferase Variants Associated With Gyrate Atrophy of the Choroid and Retina."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      The deficit of hOAT leads to a 10-to-15 fold increase in the plasmatic L-Orn concentration, along with a small reduction in the levels of glutamate, glutamine, lysine and creatine
    explanation: >-
      Review text supports secondary reductions in amino-acid and creatine
      pools downstream of hOAT deficiency.
  - reference: PMID:32418451
    reference_title: "First report of c.425-1G>A mutation in ornithine aminotransferase gene causing gyrate atrophy of the choroid and retina with hyperornithinemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine.
    explanation: >-
      Case-report abstract supports low cerebral creatine alongside extraocular
      neurologic and neuromuscular manifestations.
  downstream:
  - target: Cognitive impairment
    description: Low cerebral creatine may contribute to cognitive impairment in the extraocular disease spectrum.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:32418451
      reference_title: "First report of c.425-1G>A mutation in ornithine aminotransferase gene causing gyrate atrophy of the choroid and retina with hyperornithinemia."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine.
      explanation: >-
        Case-report abstract colocates cognitive impairment and low cerebral
        creatine in the clinical spectrum.
  - target: Muscle weakness
    description: Low cerebral creatine and secondary metabolic imbalance may contribute to muscle weakness in some patients.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:32418451
      reference_title: "First report of c.425-1G>A mutation in ornithine aminotransferase gene causing gyrate atrophy of the choroid and retina with hyperornithinemia."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine.
      explanation: >-
        Case-report abstract links muscle weakness with low cerebral creatine
        in an affected patient.
phenotypes:
- name: Nyctalopia
  category: Ophthalmologic
  description: >-
    Night blindness is typically the earliest visual symptom, starting in the
    first decade of life.
  phenotype_term:
    preferred_term: Nyctalopia
    term:
      id: HP:0000662
      label: Nyctalopia
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Night blindness, cataracts, vision loss, and impaired cognitive functions can be seen.
    explanation: >-
      This directly supports nyctalopia as part of the core ophthalmologic
      phenotype.
  - reference: PMID:34894815
    reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients usually present with night blindness that starts in the first decade of life followed by visual field constriction and eventually diminution of the central visual acuity and blindness.
    explanation: >-
      Review confirms night blindness as the presenting symptom beginning in
      the first decade of life.
- name: Cataract
  category: Ophthalmologic
  description: >-
    Cataracts are a frequent component of the progressive eye disease.
  phenotype_term:
    preferred_term: Cataract
    term:
      id: HP:0000518
      label: Cataract
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Night blindness, cataracts, vision loss, and impaired cognitive functions can be seen.
    explanation: >-
      This directly supports cataract as a common ophthalmologic manifestation.
  - reference: PMID:34894815
    reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes.
    explanation: >-
      Review confirms cataract as one of the characteristic ophthalmic
      manifestations.
- name: Visual loss
  category: Ophthalmologic
  description: >-
    Progressive retinal degeneration leads to declining visual function over
    time, ultimately progressing to blindness.
  phenotype_term:
    preferred_term: Progressive visual loss
    term:
      id: HP:0000529
      label: Progressive visual loss
    clinical_course: PROGRESSIVE
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Night blindness, cataracts, vision loss, and impaired cognitive functions can be seen.
    explanation: >-
      This directly supports progressive visual loss as a core phenotype.
  - reference: PMID:34340878
    reference_title: "A review of treatment modalities in gyrate atrophy of the choroid and retina (GACR)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      GACR is characterised by vision decline in early life eventually leading to complete blindness, and high plasma ornithine levels.
    explanation: >-
      Systematic review confirms vision decline progressing to complete
      blindness.
- name: Cognitive impairment
  category: Neurologic
  description: >-
    Cognitive impairment can be present in some affected individuals alongside
    the core ophthalmologic manifestations, although most patients have
    unaffected cognition.
  phenotype_term:
    preferred_term: Cognitive impairment
    term:
      id: HP:0100543
      label: Cognitive impairment
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Night blindness, cataracts, vision loss, and impaired cognitive functions can be seen.
    explanation: >-
      This directly supports cognitive impairment as part of the clinical
      spectrum of gyrate atrophy due to OAT deficiency.
  - reference: PMID:34395527
    reference_title: "Molecular and Cellular Studies Reveal Folding Defects of Human Ornithine Aminotransferase Variants Associated With Gyrate Atrophy of the Choroid and Retina."
    supports: PARTIAL
    evidence_source: IN_VITRO
    snippet: >-
      In most GA patients cognition is unaffected
    explanation: >-
      This full-text review notes that cognition is unaffected in most patients,
      indicating cognitive impairment is a variable rather than universal feature.
- name: Myopia
  category: Ophthalmologic
  description: >-
    Myopia develops during childhood and is a characteristic early ophthalmic
    feature of gyrate atrophy.
  phenotype_term:
    preferred_term: Myopia
    term:
      id: HP:0000545
      label: Myopia
  evidence:
  - reference: PMID:34894815
    reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes.
    explanation: >-
      Review identifies myopia as one of the characteristic ophthalmic
      manifestations of gyrate atrophy.
  - reference: PMID:34395527
    reference_title: "Molecular and Cellular Studies Reveal Folding Defects of Human Ornithine Aminotransferase Variants Associated With Gyrate Atrophy of the Choroid and Retina."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Patients develop myopia during childhood, and show a progressive decrease in visual acuity from the 2° to the 3° decade leading to blindness within the 5° decade
    explanation: >-
      Full-text review confirms childhood-onset myopia as a typical feature.
- name: Chorioretinal atrophy
  category: Ophthalmologic
  description: >-
    Progressive chorioretinal atrophy is the hallmark ophthalmologic finding,
    with characteristic patches of atrophy in the peripheral retina extending
    into the macular area.
  phenotype_term:
    preferred_term: Chorioretinal atrophy
    term:
      id: HP:0000533
      label: Chorioretinal atrophy
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:34894815
    reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      leads primarily to characteristic ophthalmic manifestations including myopia, cataract, progressive chorioretinal atrophy, and macular changes.
    explanation: >-
      Review identifies progressive chorioretinal atrophy as a characteristic
      ophthalmic manifestation.
  - reference: PMID:33068755
    reference_title: "Deficit of human ornithine aminotransferase in gyrate atrophy: Molecular, cellular, and clinical aspects."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Gyrate Atrophy (GA) of the choroid and retina (MIM# 258870) is an autosomal recessive disorder due to mutations of the OAT gene encoding ornithine-delta-aminotransferase (OAT), associated with progressive retinal deterioration and blindness.
    explanation: >-
      Confirms progressive retinal deterioration as a defining feature.
- name: Constriction of peripheral visual field
  category: Ophthalmologic
  description: >-
    Visual field constriction follows the onset of night blindness as
    chorioretinal atrophy progresses from the periphery toward the macula.
  phenotype_term:
    preferred_term: Constriction of peripheral visual field
    term:
      id: HP:0001133
      label: Constriction of peripheral visual field
    clinical_course: PROGRESSIVE
  evidence:
  - reference: PMID:34894815
    reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients usually present with night blindness that starts in the first decade of life followed by visual field constriction and eventually diminution of the central visual acuity and blindness.
    explanation: >-
      Review describes visual field constriction as part of the progressive
      ophthalmologic course.
- name: Hyperornithinemia
  category: Metabolic
  description: >-
    Markedly elevated plasma ornithine is the defining biochemical hallmark of
    the disorder, resulting from impaired ornithine catabolism due to OAT
    deficiency.
  phenotype_term:
    preferred_term: Hyperornithinemia
    term:
      id: HP:0012026
      label: Hyperornithinemia
  evidence:
  - reference: PMID:33068755
    reference_title: "Deficit of human ornithine aminotransferase in gyrate atrophy: Molecular, cellular, and clinical aspects."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OAT is mainly involved in ornithine catabolism in adults, thus explaining the hyperornithinemia as hallmark of the disease.
    explanation: >-
      Review directly identifies hyperornithinemia as the hallmark of the
      disease.
  - reference: PMID:34894815
    reference_title: "Gyrate Atrophy of the Choroid and Retina: A Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Gyrate atrophy (GA) of the choroid and retina is a rare autosomal recessive genetic condition characterized by elevation of the plasma level of the amino acid ornithine due to deficiency of the enzyme ornithine ketoacid aminotransferase.
    explanation: >-
      Review confirms elevated plasma ornithine as the defining biochemical
      feature.
- name: Muscle weakness
  category: Musculoskeletal
  description: >-
    Muscle weakness and hypotonia can occur in some patients with gyrate atrophy,
    associated with low cerebral creatine levels.
  phenotype_term:
    preferred_term: Muscle weakness
    term:
      id: HP:0001324
      label: Muscle weakness
  evidence:
  - reference: PMID:32418451
    reference_title: "First report of c.425-1G>A mutation in ornithine aminotransferase gene causing gyrate atrophy of the choroid and retina with hyperornithinemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine.
    explanation: >-
      Case report identifies muscle weakness as a clinical manifestation
      associated with gyrate atrophy and hyperornithinemia.
genetic:
- name: OAT
  association: Loss of function mutation
  gene_term:
    preferred_term: OAT
    term:
      id: hgnc:8091
      label: OAT
  evidence:
  - reference: PMID:34395527
    reference_title: "Molecular and Cellular Studies Reveal Folding Defects of Human Ornithine Aminotransferase Variants Associated With Gyrate Atrophy of the Choroid and Retina."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      The deficit of human ornithine aminotransferase (hOAT) is responsible for gyrate atrophy (GA), a rare recessive inherited disorder.
    explanation: >-
      This directly supports OAT deficiency as the causal genetic lesion.
  - reference: PMID:34340878
    reference_title: "A review of treatment modalities in gyrate atrophy of the choroid and retina (GACR)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Gyrate atrophy of the choroid and retina (GACR) is a rare inborn error of amino acid metabolism caused by bi-allelic variations in OAT.
    explanation: >-
      Systematic review confirms bi-allelic OAT mutations as the genetic cause.
  - reference: CGGV:assertion_edbab666-9ae6-46db-b818-809a4bf8333e-2019-07-10T160000.000Z
    reference_title: "OAT / ornithine aminotransferase deficiency (Definitive)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "OAT | HGNC:8091 | ornithine aminotransferase deficiency | MONDO:0009796 | AR | Definitive"
    explanation: ClinGen classifies the OAT-ornithine aminotransferase deficiency gene-disease relationship as definitive with autosomal recessive inheritance.
biochemical:
- name: Plasma ornithine
  presence: INCREASED
  context: >-
    Elevated plasma ornithine is the core biochemical hallmark of the disorder,
    with levels typically elevated 10- to 15-fold above normal.
  biomarker_term:
    preferred_term: L-ornithine
    term:
      id: CHEBI:15729
      label: L-ornithine
  readouts:
  - target: Hyperornithinemia
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >-
      Elevated plasma L-ornithine directly reports the hyperornithinemia caused
      by impaired OAT-mediated ornithine catabolism.
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      All patients had high plasma ornithine levels at the time of diagnosis, and they were all started on an arginine-restricted diet.
    explanation: >-
      This directly supports hyperornithinemia as the defining biochemical
      abnormality.
  - reference: PMID:34395527
    reference_title: "Molecular and Cellular Studies Reveal Folding Defects of Human Ornithine Aminotransferase Variants Associated With Gyrate Atrophy of the Choroid and Retina."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      The deficit of hOAT leads to a 10-to-15 fold increase in the plasmatic L-Orn concentration, along with a small reduction in the levels of glutamate, glutamine, lysine and creatine
    explanation: >-
      Full-text review quantifies the magnitude of ornithine elevation and
      notes associated reductions in glutamate, glutamine, lysine, and creatine.
- name: Cerebral creatine
  presence: DECREASED
  context: >-
    Low cerebral creatine has been reported with extraocular neurologic and
    neuromuscular manifestations in OAT deficiency and reflects secondary
    amino-acid/creatine metabolic imbalance.
  biomarker_term:
    preferred_term: creatine
    term:
      id: CHEBI:16919
      label: creatine
  readouts:
  - target: Secondary amino acid and creatine depletion
    relationship: READOUT_OF
    direction: NEGATIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >-
      Low cerebral creatine reports the secondary creatine depletion node that
      may contribute to extraocular neurologic and neuromuscular features.
  evidence:
  - reference: PMID:32418451
    reference_title: "First report of c.425-1G>A mutation in ornithine aminotransferase gene causing gyrate atrophy of the choroid and retina with hyperornithinemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      the increased ornithine level is the clinical manifestation of gyrate atrophy of choroid and retina, muscle weakness, moderate mental retardation, and low cerebral creatine.
    explanation: >-
      Case-report abstract supports low cerebral creatine as a biochemical
      finding in OAT deficiency with extraocular manifestations.
diagnosis:
- name: OAT molecular genetic testing
  description: >-
    Molecular testing confirms the diagnosis by identifying pathogenic OAT
    variants.
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: MAXO:0000533
      label: molecular genetic testing
    qualifiers:
    - predicate:
        preferred_term: has participant
        term:
          id: RO:0000057
          label: has participant
      value:
        preferred_term: OAT
        term:
          id: hgnc:8091
          label: OAT
  results: Pathogenic OAT variants in a patient with gyrate atrophy and hyperornithinemia.
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients followed by the Gazi University Faculty of Medicine, Department of Pediatric Metabolism and Nutrition, and Department of Ophthalmology who were genetically or biochemically diagnosed with GACR were included in the study.
    explanation: >-
      This directly supports molecular or biochemical confirmation as part of the
      diagnostic framework.
treatments:
- name: Arginine-restricted diet
  description: >-
    Dietary arginine restriction is used to improve metabolic control and lower
    plasma ornithine burden.
  treatment_term:
    preferred_term: dietary intervention
    term:
      id: MAXO:0000088
      label: dietary intervention
  target_phenotypes:
  - preferred_term: Hyperornithinemia
    term:
      id: HP:0012026
      label: Hyperornithinemia
  target_mechanisms:
  - target: Hyperornithinemia
    treatment_effect: INHIBITS
    description: >-
      Arginine or protein restriction lowers ornithine burden, targeting the
      central hyperornithinemia node upstream of retinal degeneration.
    evidence:
    - reference: PMID:34340878
      reference_title: "A review of treatment modalities in gyrate atrophy of the choroid and retina (GACR)."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Protein-restricted diets lowered ornithine levels ranging from 16.0-91.2%."
      explanation: >-
        Systematic review directly supports dietary protein or arginine
        restriction reducing the hyperornithinemia treatment target.
    - reference: PMID:10655512
      reference_title: "Correction of ornithine accumulation prevents retinal degeneration in a mouse model of gyrate atrophy of the choroid and retina."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: >-
        an arginine-restricted diet substantially reduces plasma ornithine
        levels and completely prevents retinal degeneration in Oat(-/-)
      explanation: >-
        Oat-deficient mouse data support arginine restriction lowering plasma
        ornithine and preventing retinal degeneration.
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      An arginine-restricted diet is combined with supplementation with pyridoxine, lysine, proline, or creatine to improve metabolic control.
    explanation: >-
      This directly supports arginine restriction as the core disease-specific
      treatment strategy.
  - reference: PMID:34340878
    reference_title: "A review of treatment modalities in gyrate atrophy of the choroid and retina (GACR)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Protein-restricted diets lowered ornithine levels ranging from 16.0-91.2%.
    explanation: >-
      Systematic review quantifies the effectiveness of protein-restricted
      diets in lowering ornithine levels.
  - reference: PMID:10655512
    reference_title: "Correction of ornithine accumulation prevents retinal degeneration in a mouse model of gyrate atrophy of the choroid and retina."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      an arginine-restricted diet substantially reduces plasma ornithine levels and completely prevents retinal degeneration in Oat(-/-)
    explanation: >-
      Mouse model demonstrates that arginine-restricted diet prevents retinal
      degeneration by reducing ornithine accumulation.
- name: Pyridoxine supplementation
  description: >-
    Pyridoxine is used as adjunctive therapy in an attempt to improve metabolic
    control in some patients, although responsiveness is mutation-dependent and
    not universal. Related supplementation regimens may also include lysine,
    proline, or creatine in combination with arginine restriction.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: pyridoxine
      term:
        id: CHEBI:16709
        label: pyridoxine
  target_phenotypes:
  - preferred_term: Hyperornithinemia
    term:
      id: HP:0012026
      label: Hyperornithinemia
  target_mechanisms:
  - target: Hyperornithinemia
    treatment_effect: MODULATES
    description: >-
      Pyridoxine can reduce ornithine levels in responsive OAT variants, so it
      is modeled as variant-dependent modulation of the hyperornithinemia node.
    evidence:
    - reference: PMID:34340878
      reference_title: "A review of treatment modalities in gyrate atrophy of the choroid and retina (GACR)."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Based primarily on case reports ornithine levels can be reduced by
        using a protein restricted diet, pyridoxine supplementation
        (variation-dependent) and/or lysine supplementation.
      explanation: >-
        Systematic review supports variant-dependent ornithine reduction with
        pyridoxine supplementation.
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      An arginine-restricted diet is combined with supplementation with pyridoxine, lysine, proline, or creatine to improve metabolic control.
    explanation: >-
      This directly supports pyridoxine supplementation as part of the standard
      metabolic management regimen.
  - reference: PMID:34340878
    reference_title: "A review of treatment modalities in gyrate atrophy of the choroid and retina (GACR)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Pyridoxine responsiveness was reported in 30% of included mutations.
    explanation: >-
      Systematic review reports that pyridoxine responsiveness is
      mutation-dependent and observed in about 30% of mutations.
- name: Adjunctive lysine, proline, and creatine supplementation
  description: >-
    Lysine, proline, or creatine supplementation may be combined with arginine
    restriction and pyridoxine to improve metabolic control; lysine has reported
    ornithine-lowering effects in case-based treatment literature, while
    creatine supplementation is biologically aligned with reported low cerebral
    creatine.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: L-lysine
      term:
        id: CHEBI:18019
        label: L-lysine
    - preferred_term: L-proline
      term:
        id: CHEBI:17203
        label: L-proline
    - preferred_term: creatine
      term:
        id: CHEBI:16919
        label: creatine
  target_phenotypes:
  - preferred_term: Hyperornithinemia
    term:
      id: HP:0012026
      label: Hyperornithinemia
  - preferred_term: Cognitive impairment
    term:
      id: HP:0100543
      label: Cognitive impairment
  - preferred_term: Muscle weakness
    term:
      id: HP:0001324
      label: Muscle weakness
  target_mechanisms:
  - target: Hyperornithinemia
    treatment_effect: MODULATES
    description: >-
      Lysine supplementation is reported with ornithine reduction in case-based
      treatment literature.
    evidence:
    - reference: PMID:34340878
      reference_title: "A review of treatment modalities in gyrate atrophy of the choroid and retina (GACR)."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Based primarily on case reports ornithine levels can be reduced by
        using a protein restricted diet, pyridoxine supplementation
        (variation-dependent) and/or lysine supplementation.
      explanation: >-
        Systematic review supports lysine supplementation as an ornithine-lowering
        adjunct in reported cases.
  - target: Secondary amino acid and creatine depletion
    treatment_effect: MODULATES
    description: >-
      Creatine supplementation targets the reported low-creatine component of
      the secondary biochemical imbalance.
    evidence:
    - reference: DOI:10.1186/s13023-026-04265-x
      reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        An arginine-restricted diet is combined with supplementation with pyridoxine, lysine, proline, or creatine to improve metabolic control.
      explanation: >-
        Cohort report supports creatine and related supplementation as part of
        metabolic management.
  evidence:
  - reference: DOI:10.1186/s13023-026-04265-x
    reference_title: "Gyrate atrophy of the choroid and retina: a tertiary center experience"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      An arginine-restricted diet is combined with supplementation with pyridoxine, lysine, proline, or creatine to improve metabolic control.
    explanation: >-
      Cohort report directly lists lysine, proline, and creatine
      supplementation as adjunctive metabolic-management options.
  - reference: PMID:34340878
    reference_title: "A review of treatment modalities in gyrate atrophy of the choroid and retina (GACR)."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Based primarily on case reports ornithine levels can be reduced by using a protein restricted diet, pyridoxine supplementation (variation-dependent) and/or lysine supplementation.
    explanation: >-
      Systematic review supports lysine supplementation as an adjunctive
      ornithine-lowering treatment.
differential_diagnoses: []
clinical_trials: []
datasets: []
📚

References & Deep Research

Deep Research

1
Asta
Asta Literature Retrieval: Pathophysiology and clinical mechanisms of ornithine aminotransferase deficiency. Core disease mechanisms, molecular...
Asta Scientific Corpus Retrieval 20 citations 2026-04-15T12:04:31.960830

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of ornithine aminotransferase deficiency. Core disease mechanisms, molecular...

This report is retrieval-only and is generated directly from Asta results.

  • Papers retrieved: 20
  • Snippets retrieved: 20

Relevant Papers

[1] The hyperornithinemia–hyperammonemia-homocitrullinuria syndrome

  • Authors: D. Martinelli, D. Diodato, Emanuela Ponzi, M. Monné, S. Boenzi et al.
  • Year: 2015
  • Venue: Orphanet Journal of Rare Diseases
  • URL: https://www.semanticscholar.org/paper/ed033868ee677da141e5c926bc7c93cac242ea06
  • DOI: 10.1186/s13023-015-0242-9
  • PMID: 25874378
  • PMCID: 4358699
  • Citations: 92
  • Influential citations: 5
  • Summary: The clinical phenotype of HHH syndrome is extremely variable and its severity does not correlate with the genotype or with recorded ammonium/ornithine plasma levels, suggesting the need for a better understanding of the still unsolved pathophysiology of the disease.
  • Evidence snippets:
  • Snippet 1 (score: 0.500) > Although the disease responds well to treatment with low risk of relapse of hyperammonemia [38], slowly progressive pyramidal signs characterize the chronic course, as also seen in argininemia [89]. However, the mechanism(s) of pyramidal dysfunction in HHH syndrome still remains to be elucidated. Creatine deficiency may contribute to the pathogenetic mechanism of the syndrome, as creatine is relevant for mitochondrial energy metabolism, regulation of glycolysis, proteins synthesis, membrane stabilization and neuromodulation [77,78,85]. This could be in line with the finding of abnormally shaped mitochondria at electron microscopy studies in skin fibroblasts, hepatocytes and muscle biopsy from HHH syndrome patients [11,23,82]. Furthermore, a mitochondrial dysfunction has been recently related to the effects of ornithine and homocitrulline in causing oxidative stress and disturbed mitochondrial homeostasis [79,80]. > A further mechanism that can be involved in the pathophysiology of HHH syndrome is related to polyamines metabolism. Shimizu and colleagues reported increased total and fractional (putrescine, cadaverine, spermine, spermidine) polyamines in one HHH syndrome patient [30]. Indeed, the clinical similarities between HHH syndrome and argininemia, which has been associated to an abnormal polyamine metabolism [91,92], may suggest a common pathogenetic mechanism causing pyramidal dysfunction. > Overall, the pathogenesis of HHH syndrome is complex and not completely understood. It is likely that different mechanisms, including the impact of low mitochondrial ornithine on UC flux, the presence of hyperammonemic crises and the disturbance of other pathways in major organs play a role in determining the heterogeneous clinical presentation of ORC1 deficiency. > In addition, as molecular studies failed to disclose a correlation between type of mutations or ornithine transport capacity and disease severity, an effect of genetic modifiers, such as ORC genes redundancy, seems to be likely, but further studies are certainly needed to clarify this point.

[2] Changes in Serum Proteomic Profiles at Different Stages of Pregnancy Toxemia in Goats

  • Authors: M. Uzti̇mür, C. N. Ünal, Gurler Akpinar
  • Year: 2025
  • Venue: Journal of Veterinary Internal Medicine
  • URL: https://www.semanticscholar.org/paper/4b9c488b5dbd65d7b26fd2ad9aed70e8c4b59942
  • DOI: 10.1111/jvim.70139
  • PMID: 40492724
  • PMCID: 12150350
  • Summary: Understanding the serum proteome profiles of goats with pregnancy toxemia might help identify the proteomes and pathways responsible for the development of this disease and improve diagnosis and treatment.
  • Evidence snippets:
  • Snippet 1 (score: 0.404) > The pathophysiology and progression of this disease are not fully understood. > Traditional biomedical research has focused on the analysis of single genes, proteins, metabolites, or metabolic pathways in diseases. This molecular reductionist approach is based on the assumption that identifying genetic variations and molecular components will lead to new treatments for diseases [13][14][15][16]. However, many diseases are complex and multifactorial, and in order to determine the phenotype of such diseases, it is necessary to understand the changes that occur in more than one gene, pathway, protein, or metabolite at the cellular, tissue, and organismal levels [17][18][19]. Therefore, in recent years, proteomics, as one field of multi-omics technologies, has helped in evaluating the complex pathogenetic mechanisms of different diseases from a broad perspective and has made substantial contributions [20,21]. In veterinary medicine, proteomic analysis of metabolic diseases such as ketosis [16], hypocalcemia [22], and fatty liver [23] in dairy cows has contributed valuable insights for the definition of new pathophysiological pathways and new diagnosis and treatment protocols for these diseases. The proteomic approach can contribute importantly to a broad and detailed understanding of the changes that occur at the organismal level associated with the increase in BHBA concentration in goats with pregnancy toxemia. Our aim was to evaluate the serum protein profiles of goats with SPT or CPT using proteomic techniques to determine the proteomic profiles of these animals and to identify the relevant pathophysiological mechanisms.

[3] L-Ornithine L-Aspartate Restores Mitochondrial Function and Modulates Intracellular Calcium Homeostasis in Parkinson’s Disease Models

  • Authors: M. Sisalli, Salvatore Della Notte, A. Secondo, C. Ventra, L. Annunziato et al.
  • Year: 2022
  • Venue: Cells
  • URL: https://www.semanticscholar.org/paper/520100d0482599c2dc27eed83d2aa026c35bc20e
  • DOI: 10.3390/cells11182909
  • PMID: 36139485
  • PMCID: 9496730
  • Citations: 8
  • Summary: Results indicate that LOLA, by interfering with those mitochondrial mechanisms related to ROS and RNS production, promotes mitochondrial functional recovery, thus confirming the tight relationship existing between cytosolic ionic homeostasis and cellular metabolism depending on the type of insult applied.
  • Evidence snippets:
  • Snippet 1 (score: 0.397) > In this regard, ornithine, a non-essential amino acid, represents an interesting compound able to potentiate mitochondrial activity due to its ability to reach this cellular organelle so important for neuronal metabolism. Indeed, ornithine, once in the mitochondria, plays a key role in the urea cycle and creates an intermediate for arginine synthesis. Ornithine is produced by the enzymatic action of arginase on arginine, which results in the production of urea and generation of ornithine. Ornithine has been shown to reduce blood ammonia concentrations by increasing ammonia detoxification in the muscle and reducing the severity of hepatic encephalopathy in cirrhosis. Recent data have demonstrated the existence of the mitochondrial enzyme ornithine transcarbamylase (OTC) specifically in neurons positive for the nitric oxide synthesis enzyme (nNOS) [16], suggesting a potential role for ornithine in the modulation of brain functions. This hypothesis is supported by the observation that a defect in the ornithine translocase enzyme, responsible for the transport of ornithine at the mitochondrial level, determines a hyperornithinemia associated with hyperammonemia, homocitrullinemia, and neurological disorders accompanied, at the cellular level, by mitochondrial dysfunction and oxidative stress [17]. However, the molecular mechanisms through which ornithine at the mitochondrial level can perform actions to improve the redox and energy properties are not entirely understood. > On these premises, the present study has been undertaken to investigate the intracellular pathways affected by ornithine treatment in in vitro models of PD, with particular regards to cellular metabolism and mitochondrial function in order to identify new and selective therapeutic strategies to prevent the neuronal dysfunction occurring in PD, and consequently to slow down disease progression. This aspect is extremely relevant considering the key role played by mitochondria in regulating synaptic activity. Therefore, a therapeutic strategy able to promote mitochondrial function might be useful to counteract the early synaptic dysfunction and the functional and pathological changes occurring in the brain of PD-affected patients.

[4] Global and Targeted Metabolomics for Revealing Metabolomic Alteration in Niemann-Pick Disease Type C Model Cells

  • Authors: Masahiro Watanabe, Masamitsu Maekawa, Keitaro Miyoshi, Toshihiro Sato, Yu Sato et al.
  • Year: 2024
  • Venue: Metabolites
  • URL: https://www.semanticscholar.org/paper/27c7aa8f74e2997a59b92b38aec1fb9ff9cbb608
  • DOI: 10.3390/metabo14100515
  • PMID: 39452896
  • PMCID: 11509386
  • Citations: 2
  • Summary: Several metabolite characteristics of Niemann-Pick disease type C that may fluctuate in a cellular model of the disease are identified using both global and targeted metabolomic analyses by liquid chromatography/tandem mass spectrometry.
  • Evidence snippets:
  • Snippet 1 (score: 0.396) > Background: Niemann-Pick disease type C (NPC) is an inherited disorder characterized by a functional deficiency of cholesterol transport proteins. However, the molecular mechanisms and pathophysiology of the disease remain unknown. Methods: In this study, we identified several metabolite characteristics of NPC that may fluctuate in a cellular model of the disease, using both global and targeted metabolomic analyses by liquid chromatography/tandem mass spectrometry (LC-MS/MS). Three cell lines, HepG2 cells (wild-type[WT]) and two NPC model HepG2 cell lines in which NPC1 was genetically ablated (knockout [KO]1 and KO2), were used for metabolomic analysis. Data were subjected to enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Results: The enrichment analysis of global metabolomics revealed that 8 pathways in KO1 and 16 pathways in KO2 cells were notably altered. In targeted metabolomics for 15 metabolites, 4 metabolites in KO1 and 10 metabolites in KO2 exhibited statistically significant quantitative changes in KO1 or KO2 relative to WT. Most of the altered metabolites were related to creatinine synthesis and cysteine metabolism pathways. Conclusions: In the future, our objective will be to elucidate the relationship between these metabolic alterations and pathophysiology.

[5] Rare biochemical & genetic conditions: clues for broader mechanistic insights

  • Authors: A. Mentis, Maria Dalamaga
  • Year: 2025
  • Venue: Cellular and Molecular Life Sciences: CMLS
  • URL: https://www.semanticscholar.org/paper/7093ca07773a0427930c301ef5c28ce909e4abf9
  • DOI: 10.1007/s00018-025-05652-6
  • PMID: 40210765
  • PMCID: 11985829
  • Summary: Evidence is synthesized demonstrating how valuable knowledge of biochemical pathways related to rare disorders can be for biomedicine, which highlights the continued value of biochemical pathways and studies in understanding human pathophysiology and drug discovery even in the genomics era.
  • Evidence snippets:
  • Snippet 1 (score: 0.384) > The discussion above highlights the importance of rare but distinct features (phenotypes, syndromes, or molecular responses) to human pathophysiology. However, distinct diseases like cancer and inborn errors of metabolism can share common and/or overlapping molecular pathways. For example, the rare biochemical disorder D-2-hydroxyglutaric aciduria type 2, which is caused by germline mutations in the isocitrate dehydrogenase 2 (IDH2) gene and which causes progressive brain damage, is treated with enasidenib, a drug that has been approved to treat a blood cancer, namely acute myeloid leukemia caused by somatic mutations in the IDH2 gene [28,29], Similarly, lonafarnib, a farnesyltransferase inhibitor with antineoplastic properties, also reduces Parkinson-related tau pathology through a lysosomeactivating mechanism involving the Rhes protein [30]. These approaches show how drugs can be repurposed based on shared mechanisms between apparently different disorders. > Additionally, biochemical substances previously considered byproducts of cellular metabolism, such as urea and lactate, have recently attracted considerable attention due to their mechanistic value. First, urea, a byproduct of nitrogen metabolism, has been reported as a cancer biomarker by increasing pyrimidine-to-purine conversion. The latter increases the number of DNA and RNA transversion mutations and, as such, increases the rates of hydrophobic tumor neoantigens responsive to immunotherapy [31]. Even if the precise impact of several variants remains unclear, enzymes that are part of the urea cycle (e.g., ornithine transcarbamylase) appear to provide metabolic clues about cancer survival and development, an area of potential future research interest [32,33]. Likewise, phenylalanine substitutions at the codon reassignment level enhance the repertoire of cell surface antigens under conditions of tryptophan depletion [34]. Third, lactate has recently been shown to be involved in DNA repair (namely, homologous recombination-mediated pathways) through lactylation of the Nijmegen breakage syndrome 1 (NBS1) protein.

[6] Common immunopathogenesis of central nervous system diseases: the protein-homeostasis-system hypothesis

  • Authors: Kyung-Yil Lee
  • Year: 2022
  • Venue: Cell & Bioscience
  • URL: https://www.semanticscholar.org/paper/2984270ae67451b93007040848d9694d19714c9f
  • DOI: 10.1186/s13578-022-00920-5
  • PMID: 36384812
  • PMCID: 9668226
  • Citations: 9
  • Influential citations: 1
  • Summary: This article proposes a common immunopathogenesis of CNS diseases, including prion diseases, Alzheimer’s disease, and genetic diseases, through the PHS hypothesis, which proposes that the immune systems in the host control those substances according to the size and biochemical properties of the substances.
  • Evidence snippets:
  • Snippet 1 (score: 0.383) > There are hundreds of genetic diseases of the CNS. The defective proteins in genetic disorders include structural proteins for neurotransmitter receptors and other receptors or ion channels on CNS cells, and proteins involved in enzymatic process, metabolism (transport), or signal transduction pathways in various communication systems [98]. Because a discussion of each genetic disease is beyond the scope of this review, only crucial points about the pathogenesis of genetic diseases are discussed. Singlegene defect diseases of the CNS can be caused by a defective product from a gene, i.e., a protein deficiency or a malfunctioning protein. In general, autosomal dominant genetic diseases are caused by structural protein defects, and autosomal recessive diseases are caused by defects in enzymatic proteins. However, certain genetic diseases that involve an enzymatic or multifunctional protein defect can induce structural cell injury during the natural course of the illness. > Patients with genetic diseases, including HD, familial JCD, GSS, and the genetic forms of AD and PD, show different clinical manifestations from other affected people in their family, including the time of onset of neurological symptoms, speed of progression of the disease, and prognosis, suggesting that phenotypes can vary even when the genotypes are identical. Likewise, similar phenotypes of CNS symptoms can be found in different genetic diseases. In genetic animal models, the phenotypes of single gene knockout can vary by strain in mice, and the clinical manifestations of a gene defect can differ between mice and humans, and mice null for some genes have also no observable phenotypic abnormalities compared with controls [99]. These findings suggest that default of a protein might be at least partly controlled by individual's control systems and that there might exist a similar immune/repair system against cell injury in genetic diseases. > The pathophysiology of most genetic diseases in the CNS is complex because any affected gene is associated with numerous proteins and their corresponding activations of genes and epigenetic changes that occur during disease processes. Thus, the use of a genetic marker for diagnosing or predicting a prognosis remains impractical in clinical settings [100].

[7] Nasopharyngeal Carcinoma Signaling Pathway: An Update on Molecular Biomarkers

  • Authors: W. Tulalamba, T. Janvilisri
  • Year: 2012
  • Venue: International Journal of Cell Biology
  • URL: https://www.semanticscholar.org/paper/307cb9186444d9dad6e2e3b53763be0de76de186
  • DOI: 10.1155/2012/594681
  • PMID: 22500174
  • PMCID: 3303613
  • Citations: 93
  • Influential citations: 5
  • Summary: The molecular signaling pathways in the NPC are discussed for the holistic view of NPC development and progression and the important insights toward NPC pathogenesis may offer strategies for identification of novel biomarkers for diagnosis and prognosis.
  • Evidence snippets:
  • Snippet 1 (score: 0.382) > In the pregenomic eras, highly integrated and complex circuitry of molecular signaling in NPC pathogenesis was only partially understood. Over the past decade, the knowledge of the molecular mechanisms in NPC carcinogenesis has been rapidly accumulated. Dysregulation and abnormal protein expression of molecules in certain signaling pathways involved in cellular functions including proliferation, adhesion, survival, and apoptosis has been demonstrated in the NPC cells. Detailed information on the complex network in signaling pathway leading to a coordinated pattern of gene expression and regulation in NPC will undoubtedly provide important clues to develop novel prognostic and therapeutic strategies for this cancer. Refining molecular markers into clinically relevant assays may assist in the detection of NPC in asymptomatic patients, as well as stage classification and monitoring disease progression and treatments. Furthermore, selective regulation of particular proteins targeting cancer cell proliferation, invasion, and apoptosis is a hopeful prospect for future anticancer therapy that slow disease progression and improve survival.

[8] Targeting Hepatic Stellate Cells for the Prevention and Treatment of Liver Cirrhosis and Hepatocellular Carcinoma: Strategies and Clinical Translation

  • Authors: Hao Xiong, Jinsheng Guo
  • Year: 2025
  • Venue: Pharmaceuticals
  • URL: https://www.semanticscholar.org/paper/76e92127053136900f7e3f10e2c9278251ced5d2
  • DOI: 10.3390/ph18040507
  • PMID: 40283943
  • PMCID: 12030350
  • Citations: 8
  • Summary: HSC-targeted approaches using specific surface markers and receptors may enable the selective delivery of drugs, oligonucleotides, and therapeutic peptides that exert optimized anti-fibrotic and anti-HCC effects.
  • Evidence snippets:
  • Snippet 1 (score: 0.379) > Significant progress has been made in elucidating the cellular and molecular mechanisms of liver fibrosis; however, only a few findings have been successfully translated into clinical applications. Firstly, the high cost of drug development and target validation necessitates prolonged timelines and substantial financial investment. Secondly, as regulatory requirements become more stringent, there is an increasing demand for drugs with well-defined clinical efficacy and safety profiles. Moreover, the efficacy observed in animal models often fails to fully translate to clinical settings due to differences in pharmacokinetics, extracellular matrix (ECM) cross-linking, and disease pathophysiology. Despite advancements in anti-fibrotic drug development, accurately identifying ideal noninvasive biomarkers for fibrotic activity and establishing consensus on optimal clinical endpoints remain significant challenges [113,114]. > Currently, addressing the underlying cause remains the only proven strategy to halt or reverse liver fibrosis progression, while the development of effective anti-fibrotic therapies continues to pose a major challenge in liver disease management. Over the past few decades, substantial progress has been made in elucidating the cellular and molecular mechanisms underlying liver fibrosis. Liver fibrosis is a complex pathological change involving multiple cells, factors, and pathways, and the study of the cellular and molecular mechanisms of its occurrence and development provides an important theoretical basis and therapeutic target for clinical drug development. It is anticipated that improved animal models and well-designed clinical trials will facilitate the successful translation of anti-fibrotic research into effective clinical treatments in the near future.

[9] The arginine metabolome in acute lymphoblastic leukemia can be targeted by the pegylated‐recombinant arginase I BCT‐100

  • Authors: Carmela De Santo, S. Booth, A. Vardon, A. Cousins, Vanessa Tubb et al.
  • Year: 2017
  • Venue: International Journal of Cancer
  • URL: https://www.semanticscholar.org/paper/ea9fca41e1911906bfea04bcb5dd83208aeaff86
  • DOI: 10.1002/ijc.31170
  • PMID: 29168171
  • PMCID: 5849425
  • Citations: 59
  • Influential citations: 4
  • Summary: It is shown that BCT‐100 is cytotoxic to ALL blasts from patients in vitro by necrosis, and is synergistic in combination with dexamethasone, and provides a new clinically relevant therapeutic approach to target arginine metabolism in ALL.
  • Evidence snippets:
  • Snippet 1 (score: 0.375) > Acute lymphoblastic leukemia (ALL) is the most common cancer of childhood. Significant progress has been made such that the majority of children will be cured of their disease through multi-drug chemotherapy regimens. However, major challenges remain. For children who are diagnosed with high-risk disease, or those who relapse the prognosis remains poor. 1 Fewer than 50% of adults will be cured despite successful induction of a complete remission with chemotherapy. 2 For those that are cured, the toxicities of treatment with chemotherapy over a 2-to 3-year period remain a lifelong burden. 3 Therefore, therapeutic strategies, which target ALL blasts through new mechanisms, but do not add to the cummulative toxicity, are urgently needed. > Arginine is a semi-essential amino acid required for protein synthesis, cell division and a number of intracellular pathways that maintain cell survival. 4,5 Although whole body arginine levels are maintained through dietary intake and resynthesis, under conditions of high demand such as inflammation, pregnancy and cancer, arginine availability is limiting for on-going cell growth and survival. Arginine is metabolized through the activity of Arginase I, II or iNOS enzymes. The enzymes ornithine transcarbamylase (OTC) and argininosuccinate synthase (ASS) provide the intracellular pathway in which normal cells can protect themselves by resynthesizing arginine from citrulline. However, cancer cells may be dependent on extracellular arginine for survivalarginine auxotrophism, due to the loss of ASS or OTC recycling enzyme expression; making them vulnerable to therapeutic arginine depletion. 6 BCT-100 is a clinical-grade, PEGylated (PEG) recombinant human arginase that catalyses the conversion of arginine to ornithine and urea, leading to arginine depletion. 7 BCT-100 has shown significant activity against solid tumors and acute myeloid leukemia both pre-clinically and in clinical trials. 8,9 Here, we investigate the role of arginine metabolism in ALL and the activity of BCT-100 as a clinically relevant therapeutic approach for ALL.

[10] New therapeutic targets in rare genetic skeletal diseases

  • Authors: M. Briggs, Peter A. Bell, M. Wright, K. A. Pirog
  • Year: 2015
  • Venue: Expert Opinion on Orphan Drugs
  • URL: https://www.semanticscholar.org/paper/1363107f71ae6d2d60abca471cddf3da5d13644b
  • DOI: 10.1517/21678707.2015.1083853
  • PMID: 26635999
  • PMCID: 4643203
  • Citations: 37
  • Influential citations: 1
  • Summary: An overview of disease mechanisms that are shared amongst groups of different GSDs and potential therapeutic approaches that are under investigation are described to generate critical mass for the identification and validation of novel therapeutic targets and biomarkers.
  • Evidence snippets:
  • Snippet 1 (score: 0.374) > proteins of the cartilage ECM such as type II collagen [50]. However, emerging knowledge suggests that the primary genetic defect may be less important than the cells' response to the expression of the mutant gene product [107]. Moreover, the largely overlooked response of a cell (i.e. chondrocyte) to the abnormal extracellular environment is also important for disease progression as illustrated by several GSDs discussed in this review. > It is important that 'omics'-based approaches and technologies are systematically applied to the study of rare GSDs so that definitive reference profiles and disease signatures are generated for each phenotype. These can then be used in a Systems Biology approach to identify both common and dissimilar pathological signatures and disease mechanisms. This approach is entirely dependent upon relevant in vitro and in vivo models (and also novel 'disease-mechanism phenocopies' [107]) for testing new diagnostic and prognostic tools and for determining the molecular mechanisms that underpin the pathophysiology so that effective therapeutic treatments can be developed and validated. This approach will eventually lead to personalized treatments and care strategies centred on shared disease mechanisms with the use of relevant biomarkers to monitor the efficacy of treatment and disease progression. > It is vital that all relevant stakeholders are involved from the outset in defining the appropriate outcomes of any potential therapeutic regime. The perceptions of a successful therapy can differ widely between the clinical academic community and the relevant patient-support groups and it is vital that there is engagement on all these issues. > In summary, the identification of causative genes and mutations for GSDs over the last 20 years, coupled with the generation and in-depth analysis of a plethora of relevant cell and mouse models, has derived new knowledge on disease mechanisms and suggested potential therapeutic targets. The fast-evolving hypothesis that clinically disparate diseases can share common disease mechanisms is a powerful concept that will generate critical mass for the identification and validation of novel therapeutic targets and biomarkers.

[11] Molecular and Cellular Studies Reveal Folding Defects of Human Ornithine Aminotransferase Variants Associated With Gyrate Atrophy of the Choroid and Retina

  • Authors: R. Montioli, G. Sgaravizzi, M. A. Desbats, S. Grottelli, C. Voltattorni et al.
  • Year: 2021
  • Venue: Frontiers in Molecular Biosciences
  • URL: https://www.semanticscholar.org/paper/75a15c9419b96982e9fe4d07c77244098e0dad96
  • DOI: 10.3389/fmolb.2021.695205
  • PMID: 34395527
  • PMCID: 8360850
  • Citations: 7
  • Summary: Six representative missense mutations present in homozygous patients concerning residues spread over the hOAT structure are considered to represent a further effort toward a comprehensive analysis of GA pathogenesis at molecular and cellular level, with important relapses for the improvement of genotype/phenotype correlations and the development of novel treatments.
  • Evidence snippets:
  • Snippet 1 (score: 0.372) > The deficit of human ornithine aminotransferase (hOAT) is responsible for gyrate atrophy (GA), a rare recessive inherited disorder. Although more than 60 disease-associated mutations have been identified to date, the molecular mechanisms explaining how each mutation leads to the deficit of OAT are mostly unknown. To fill this gap, we considered six representative missense mutations present in homozygous patients concerning residues spread over the hOAT structure. E. coli expression, spectroscopic, kinetic and bioinformatic analyses, reveal that the R154L and G237D mutations induce a catalytic more than a folding defect, the Q90E and R271K mutations mainly impact folding efficiency, while the E318K and C394Y mutations give rise to both folding and catalytic defects. In a human cellular model of disease folding-defective variants, although at a different extent, display reduced protein levels and/or specific activity, due to increased aggregation and/or degradation propensity. The supplementation with Vitamin B6, to mimic a treatment strategy available for GA patients, does not significantly improve the expression/activity of folding-defective variants, in contrast with the clinical responsiveness of patients bearing the E318K mutation. Thus, we speculate that the action of vitamin B6 could be also independent of hOAT. Overall, these data represent a further effort toward a comprehensive analysis of GA pathogenesis at molecular and cellular level, with important relapses for the improvement of genotype/phenotype correlations and the development of novel treatments.

[12] Novel Approaches to Studying SLC13A5 Disease

  • Authors: Adriana S. Beltran
  • Year: 2024
  • Venue: Metabolites
  • URL: https://www.semanticscholar.org/paper/8469c534cd81d96f84b61e2d963dead12088feb7
  • DOI: 10.3390/metabo14020084
  • PMID: 38392976
  • PMCID: 10890222
  • Citations: 2
  • Summary: Current technologies for generating patient-specific induced pluripotent stem cells (iPSCs) and their inherent advantages and limitations are discussed, followed by a summary of the methods for differentiating iPSCs into neurons, hepatocytes, and organoids.
  • Evidence snippets:
  • Snippet 1 (score: 0.372) > The precise pathophysiology underlying how SLC13A5 loss-of-function results in epilepsy refractory to treatment is a subject of open and ongoing research. Several hypotheses suggest SLC13A5 alters metabolic pathways, leading to neuronal dysfunction. Conversely, therapeutic inhibition of NaCT in the liver is a target to improve metabolic diseases, including non-alcoholic fatty liver disease, obesity, and insulin resistance. Thus, functionally accurate modeling and characterization of the mechanisms involved in citrate transport disruption are critical for understanding its role in human disease. > IPSC-derived cellular systems are a powerful tool for modeling rare human genetic diseases, such as SLC13A5 (Figure 5). IPSCs derived from patients containing the genetic information of the disease can overcome the limitations of animal models, providing access to relevant human cell types that recapitulate the disease phenotype. For instance, patient-derived iPSCs differentiated into neurons or hepatocytes can be used to investigate molecular and cellular mechanisms, including citrate transport and accumulation, energy metabolism, oxidative stress, and other cellular processes. They can also be used to define the spectrum of the disease and how different mutations might lead to various disease severities, screen for potential therapeutic compounds that can restore the transporter function or ameliorate the symptoms, and enable personalized medicine approaches that can tailor treatments to individual patients based on their genetic background and disease severity. > transport disruption are critical for understanding its role in human disease. > IPSC-derived cellular systems are a powerful tool for modeling rare human genetic diseases, such as SLC13A5 (Figure 5). IPSCs derived from patients containing the genetic information of the disease can overcome the limitations of animal models, providing access to relevant human cell types that recapitulate the disease phenotype. For instance, patient-derived iPSCs differentiated into neurons or hepatocytes can be used to investigate molecular and cellular mechanisms, including citrate transport and accumulation, energy metabolism, oxidative stress, and other cellular processes.

[13] Clinical and biochemical characteristics of patients with ornithine transcarbamylase deficiency and in silico analysis of OTC gene

  • Authors: Yinchun Zhang, Xia Gu, C. Shi, Hui Xiong, Dongfan Xiao et al.
  • Year: 2025
  • Venue: Orphanet Journal of Rare Diseases
  • URL: https://www.semanticscholar.org/paper/0f0c21efb1a97166692a0ceaba314bdbb2db8cd4
  • DOI: 10.1186/s13023-025-03624-4
  • PMID: 40102887
  • PMCID: 11916849
  • Citations: 1
  • Summary: A retrospective analysis of the clinical and biochemical features of 12 patients with OTCD and examined their metabolite profiles broadened the genetic variation spectrum of OTCD and provided substantial evidence for genetic counselling to affected families.
  • Evidence snippets:
  • Snippet 1 (score: 0.372) > This study seeks to elucidate the clinical and biochemical features of Ornithine transcarbamylase deficiency (OTCD), a pleomorphic congenital hyperammonemia disorder with a non-specific clinical phenotype. Additionally, the research aims to analyze the mutation spectrum of the OTC gene and its potential association with phenotype, as well as to perform an in silico analysis of novel OTC variants to elucidate their structure-function relationship. In this study, we conducted a retrospective analysis of the clinical and biochemical features of 12 patients with OTCD and examined their metabolite profiles. Additionally, we reviewed existing literature to explore the range of mutations in the OTC gene and their possible associations with phenotypic outcomes. Furthermore, we employed the high ambiguity-driven protein-protein docking (HADDOCK) algorithm and protein-ligand interaction profiler (PLIP) to predict the pathogenicity of these mutations and elucidate the underlying mechanisms of pathogenesis in novel variants of the OTC gene. Nine cases, all of which were male, presented with early onset, while two cases, all of which were female, exhibited late onset. Additionally, one male case was asymptomatic. The ages of the patients at the time of diagnosis ranged from 1 day to 12 years. Peak plasma ammonia levels were found to be higher in patients with early onset compared to those with late onset. Molecular analyses identified a total of 12 different mutations, including two novel mutations (V323G and R320P). In silico analysis indicated a potential difference in affinity between wild-type and mutant OTCase, with V323G and R320P mutations leading to a decreased binding ability of OTCase to the substrate, potentially disrupting its function. This study broadened the genetic variation spectrum of OTCD and provided substantial evidence for genetic counselling to affected families. Additionally, we elucidated variant data of OTC in Chinese patients through comprehensive literature review. Given the ongoing uncertainty surrounding the genotype-phenotype correlation of OTCD, the results of our in silico analysis can contribute to a deeper understanding of this complex, rare, and severe genetic disorder.

[14] Lactate metabolism and lactylation in kidney diseases: insights into mechanisms and therapeutic opportunities

  • Authors: Yuhua Cheng, Linjuan Guo
  • Year: 2025
  • Venue: Renal Failure
  • URL: https://www.semanticscholar.org/paper/6208b88884af543f7c97d2e70ed6b727dcfb4f58
  • DOI: 10.1080/0886022X.2025.2469746
  • PMID: 40012230
  • PMCID: 11869332
  • Citations: 11
  • Summary: A review examines the role of lactate esters, especially lactylation, in kidney diseases, with a focus on their regulatory mechanisms and potential as therapeutic targets.
  • Evidence snippets:
  • Snippet 1 (score: 0.371) > Lactate metabolism and its post-translational modifications, particularly lactylation, play critical roles in the pathophysiology of various kidney diseases, including AKI, DKD, and ccRCC (Figure 1). The kidney's ability to metabolize lactate is crucial for maintaining renal function under normal conditions. However, in pathological states, impaired lactate metabolism leads to its accumulation, exacerbating renal dysfunction and disease progression. For more details on lactate metabolism and kidney diseases, refer to previous reviews [2,3,25]. > Lactylation influences gene transcription, protein function, and cellular metabolism, contributing to inflammatory responses, mitochondrial dysfunction, and tumor progression. > Understanding the mechanisms of lactate metabolism and lactylation in kidney diseases opens new avenues for therapeutic interventions. Targeting these metabolic pathways could mitigate renal injury and improve patient outcomes. Future research should focus on elucidating the specific pathways and molecular targets affected by lactate and lactylation and developing inhibitors to modulate these processes. Clinical trials are necessary to validate the efficacy and safety of these therapies. Overall, the lactate-lactylation axis is a promising target for novel therapeutic strategies aimed at treating kidney diseases and improving renal health.

[15] Future research trends in understanding the mechanisms underlying allergic diseases for improved patient care

  • Authors: H. Breiteneder, Z. Diamant, T. Eiwegger, W. Fokkens, C. Traidl‐Hoffmann et al.
  • Year: 2019
  • Venue: Allergy
  • URL: https://www.semanticscholar.org/paper/e19b0755c4f4903f68377333676edebf9bd73c89
  • DOI: 10.1111/all.13851
  • PMID: 31056763
  • PMCID: 6973012
  • Citations: 90
  • Influential citations: 3
  • Summary: Recent developments in research and patient care and future trends in the discipline are reviewed and topics on food allergy, biologics, small molecules, and novel therapeutic concepts in allergen‐specific immunotherapy for airway disease are highlighted.
  • Evidence snippets:
  • Snippet 1 (score: 0.370) > The past decades have witnessed extensive progress in unraveling cellular and molecular mechanisms of immune regulation in asthma, allergic diseases, organ transplantation, autoimmune diseases, tumor biology, and chronic infections. 1,2 Consequently, a better understanding of the functions, the reciprocal regulation, and the counterbalance of subsets of immune and inflammatory cells but also structural cells-for example, epithelial and vascular cells, airway smooth muscle cells, neuroendocrine system-that interact via various intercellular messengers will indicate avenues for immune interventions and novel treatment modalities of allergic diseases and immunological disorders. It is generally expected that drug development in the next decades will show a significant shift from chemicals to biologicals. > After more than 20 years without any breakthrough drug becoming available for patients, several disciplines including allergology are now experiencing extraordinary times with the recent licensing of several major biological drugs and novel allergen-specific immunotherapy (AIT) vaccines. Several biological modifiers of the immune response targeting intracellular messengers or their receptors have been developed to date. [3][4][5][6][7][8] In addition, a number of promising small molecule drugs and vaccines are in the development pipeline. [9][10][11] This new era is now calling for the development of biomarkers and phenoand endotyping of diseases for customized patient care, which is termed stratified medicine, precision medicine, or personalized medicine. 4 Distinguishing phenotypes of a complex disease covers the observable clinically relevant properties of the disease but does not show a direct relationship to disease etiology and pathophysiology. In a complex condition, such as asthma, different pathogenetic mechanisms can induce similar clinical manifestations; however, they may require different treatment approaches. 12,13 These pathophysiological mechanisms underlying disease subgroups are addressed by the term "endotype." [12][13][14] Classification of complex diseases based on the concept of endotypes provides advantages for epidemiological, genetic, and drug-related studies. Accurate endotyping by using reliable biomarkers reflects the natural history of the disease and aims to predict the response to (targeted) treatments. 15 Recent studies have focused on better understanding

[16] The ties that bind: functional clusters in limb-girdle muscular dystrophy

  • Authors: E. Barton, C. A. Pacak, Whitney L. Stoppel, P. Kang
  • Year: 2020
  • Venue: Skeletal Muscle
  • URL: https://www.semanticscholar.org/paper/653422e1a9dc9cc7f16758b10f3f203155bc68c9
  • DOI: 10.1186/s13395-020-00240-7
  • PMID: 32727611
  • PMCID: 7389686
  • Citations: 24
  • Summary: A deeper understanding of these disease pathways could yield a new generation of precision therapies that would each be expected to treat a broader range of LGMD patients than a single subtype, thus expanding the scope of the molecular medicines that may be developed for this complex array of muscular dystrophies.
  • Evidence snippets:
  • Snippet 1 (score: 0.364) > Pyridine nucleotide-disulfide reductase [55] Many of the protein functions listed require further confirmation or are disputed these methodologies. Those patients with moderate disease phenotypes regardless of the underlying causative gene mutation would likely fall into a category where there may be interest in testing a pharmacological treatment (that could be halted) but reduced interest in a more permanent experimental strategy. For all of the above-mentioned reasons, the identification of unifying therapeutic targets applicable to multiple subtypes of > LGMDs is highly desirable. > To identify such targets, we should first consider the question: What binds all of these LGMDs together? The two core phenotypic features are progressive proximal muscle weakness, along with characteristic signs of muscle fiber destruction on biopsy, referred to as "dystrophic" features. Nuances in clinical presentation have helped to distinguish some of the LGMDs, such as the frequent occurrence of difficulty walking on tiptoes in LGMD R2 (LGMD2B), caused by dysferlin deficiency. However, heterogeneity associated with variable ages of onset and ranges of severity makes it generally difficult to distinguish and diagnose LGMD subtypes based on clinical presentation alone. A change in perspective is in order to aid in understanding disease pathways responsible for clinical features even when the genetic mutation is unknown. Further, given the large number of genespecific LGMD subtypes, it could very well be that several major disease mechanisms may be shared across the family of diseases. Yet despite careful studies that have collectively determined the cellular localization of most proteins associated with LGMD (Fig. 1), there is limited knowledge of potentially unifying molecular disease mechanisms. We assert that the identification of functional clusters of these proteins, grouped by such common mechanisms, will streamline our understanding of the disease processes and identify therapeutic targets relevant to individuals in multiple disease subgroups, including individuals whose pathogenic mutations have not been found. By extension, this approach may serve as a tool to not only find common mechanisms, but may also help to distinguish LGMD subtypes that do not share similar functional patterns, and afford further refinement of potential treatments.

[17] The ties that bind: functional clusters in limb-girdle muscular dystrophy

  • Authors: E. Barton, C. A. Pacak, Whitney L. Stoppel, Peter B. Kang
  • Year: 2020
  • Venue: Skeletal Muscle
  • URL: https://www.semanticscholar.org/paper/3493c658bb8716d789a05ddf292162832e064e47
  • DOI: 10.1186/s13395-020-00240-7
  • Summary: A deeper understanding of these disease pathways could yield a new generation of precision therapies that would each be expected to treat a broader range of LGMD patients than a single subtype, thus expanding the scope of the molecular medicines that may be developed for this complex array of muscular dystrophies.
  • Evidence snippets:
  • Snippet 1 (score: 0.364) > Pyridine nucleotide-disulfide reductase [55] Many of the protein functions listed require further confirmation or are disputed these methodologies. Those patients with moderate disease phenotypes regardless of the underlying causative gene mutation would likely fall into a category where there may be interest in testing a pharmacological treatment (that could be halted) but reduced interest in a more permanent experimental strategy. For all of the above-mentioned reasons, the identification of unifying therapeutic targets applicable to multiple subtypes of > LGMDs is highly desirable. > To identify such targets, we should first consider the question: What binds all of these LGMDs together? The two core phenotypic features are progressive proximal muscle weakness, along with characteristic signs of muscle fiber destruction on biopsy, referred to as "dystrophic" features. Nuances in clinical presentation have helped to distinguish some of the LGMDs, such as the frequent occurrence of difficulty walking on tiptoes in LGMD R2 (LGMD2B), caused by dysferlin deficiency. However, heterogeneity associated with variable ages of onset and ranges of severity makes it generally difficult to distinguish and diagnose LGMD subtypes based on clinical presentation alone. A change in perspective is in order to aid in understanding disease pathways responsible for clinical features even when the genetic mutation is unknown. Further, given the large number of genespecific LGMD subtypes, it could very well be that several major disease mechanisms may be shared across the family of diseases. Yet despite careful studies that have collectively determined the cellular localization of most proteins associated with LGMD (Fig. 1), there is limited knowledge of potentially unifying molecular disease mechanisms. We assert that the identification of functional clusters of these proteins, grouped by such common mechanisms, will streamline our understanding of the disease processes and identify therapeutic targets relevant to individuals in multiple disease subgroups, including individuals whose pathogenic mutations have not been found. By extension, this approach may serve as a tool to not only find common mechanisms, but may also help to distinguish LGMD subtypes that do not share similar functional patterns, and afford further refinement of potential treatments.

[18] Aberrant NLRP3 Inflammasome Activation Ignites the Fire of Inflammation in Neuromuscular Diseases

  • Authors: Christine Péladeau, J. Sandhu
  • Year: 2021
  • Venue: International Journal of Molecular Sciences
  • URL: https://www.semanticscholar.org/paper/763a36db080236fca8cde89b2afcdf056f3584d0
  • DOI: 10.3390/ijms22116068
  • PMID: 34199845
  • PMCID: 8200055
  • Citations: 18
  • Influential citations: 1
  • Summary: Whether therapeutic targeting of the NLRP3 inflammasome components is a viable approach to alleviating the detrimental phenotype of neuromuscular diseases and improving clinical outcomes is examined.
  • Evidence snippets:
  • Snippet 1 (score: 0.363) > Despite a large number of mechanisms that have been identified in muscle degeneration and nerve cell loss, none have proven to be the primary cause of the disease. There is much need for a deeper understanding of the biology of the pathogeneses and the molecular mechanisms that are activated early in the diseases in order to identify "druggable" targets and disease-modifying treatments for these devastating diseases. > Human iPSC technologies are emerging as useful platforms for disease modeling to study pathogenic mechanisms and discover novel therapeutics for neuromuscular diseases [211,237]. Indeed, patient-derived iPSCs are being used to create a "patient-in-adish" disease model to derive relevant cell types for testing potential therapeutics, paving the way towards personalized medicine. This approach allows drug screening in a dish prior to administration to patients and "bench-to-bedside" translation of potential therapies. Additionally, iPSCs may also be used to stratify patients with various phenotypes and guide future clinical trials for bringing improved therapies to patients. Since multiple cell types are involved in disease pathogenesis, future research efforts need to be focused on deciphering "disease-specific signatures" at single-cell resolution, and not only in neuronal cells but also in non-neuronal cells. The application of modern technologies, including single-cell RNA sequencing and spatial transcriptomics, to neuromuscular diseases, will allow to ascertain cellular vulnerability and cell-specific mechanisms during various stages of disease progression. > The vital roles of the NLRP3 inflammasome in neuromuscular diseases such as DMD, LGMD and ALS, reveal that targeting this pathway is indeed a promising therapeutic strategy. Dysregulation of the NLRP3 inflammasome in muscle tissues by muscle damage, membrane instability, extracellular ATP and Ca 2+ ions or signals from infiltrating immune cells, clearly impacts the progression of neuromuscular and neurodegenerative disorders. Thus, modulation of these pathways involved with activation and assembly of NLRP3 inflammasome could be truly beneficial.

[19] Role of Transcriptomics in Precision Oncology

  • Authors: Ruby Srivastava
  • Year: 2024
  • Venue: Reports of Radiotherapy and Oncology
  • URL: https://www.semanticscholar.org/paper/0bd862558bbb7286336111d9dfd232b5f905d3d9
  • DOI: 10.5812/rro-142195
  • Citations: 4
  • Summary: : Transcriptome profiling is one of the most widely used approaches in the field of multiomics research. It plays a crucial role in the prognostic, diagnostic, and predictive treatment of cancer patients. Novel next-generation sequencing (NGS) technologies permit the identification of cancer biomarkers, gene signatures, and their abnormal expression, affecting oncogenic and molecular targets and novel biomarkers for cancer therapies. Multiomics studies have changed the overall understanding o...
  • Evidence snippets:
  • Snippet 1 (score: 0.363) > : Transcriptome profiling is one of the most widely used approaches in the field of multiomics research. It plays a crucial role in the prognostic, diagnostic, and predictive treatment of cancer patients. Novel next-generation sequencing (NGS) technologies permit the identification of cancer biomarkers, gene signatures, and their abnormal expression, affecting oncogenic and molecular targets and novel biomarkers for cancer therapies. Multiomics studies have changed the overall understanding of cancer and opened a precise perspective for tumor diagnostics and therapy. The use of these approaches has strengthened our understanding of disease pathophysiology and classifications at the molecular level, including specific interference with drug mechanisms of action. Still, it has limited added value in the clinical setting. The omics data on precision medicine include the application of data from genes, transcripts, and proteins for diagnosis, monitoring of diseases, risk factor determination, counseling, and development of novel therapeutics. Bioinformatics applications have expanded statistics-based analysis toward deriving molecular pathways and process models for characterizing phenotypes and drug action mechanisms. In this review, we will discuss transcriptomics and interference analysis that allows the identification of predictive biomarkers at the molecular level to test drug response and analyze the molecular process interface of disease progression-relevant pathophysiology and mechanism of action to propose predictive biomarkers.

[20] Combined metabolomics and network pharmacology to elucidate the mechanisms of Dracorhodin Perchlorate in treating diabetic foot ulcer rats

  • Authors: Pin Deng, Huan Liang, Shulong Wang, Rui-Lin Hao, Jin-Feng Han et al.
  • Year: 2022
  • Venue: Frontiers in Pharmacology
  • URL: https://www.semanticscholar.org/paper/29251bcf9cf6d00e07f61c3ab592e54101f7857b
  • DOI: 10.3389/fphar.2022.1038656
  • PMID: 36532755
  • PMCID: 9752146
  • Citations: 15
  • Summary: Research based on metabolomics and network pharmacology demonstrated that DP improves wound healing in DFU through multiple targets and pathways, and it can potentially be used for DFU treatment.
  • Evidence snippets:
  • Snippet 1 (score: 0.362) > Network pharmacology is a method based on bioinformatics and systems pharmacology (Zhong et al., 2018), which assess drug polypharmacological effects at the molecular level to investigate the interaction between natural products and targets and confirm major mechanisms (Sheng et al., 2014). Network pharmacology can help investigate reaction networks and key targets and metabolites (Yu et al., 2012). This integrated strategy discovers the crucial targets and important mechanisms of DP treating DFU rat by integrating network pharmacology and metabolomics. > Arginine is important in cellular physiology. Like other amino acids, it plays a role in the production of proteins. The conversion of arginine to nitric oxide and other polyamines has a role in cell signalling and cell proliferation. Arginine is an essential substrate for wound healing processes due to its multiple functions. In numerous studies, supplying arginine alleviates or improves healing (Witte, 2003). A previous study suggested that arginine metabolite-nitric oxide played a key role in wound healing. As a semi-essential amino acid, arginine is metabolised by arginase and nitric oxide synthase. Woundhealing emphasises the important role of strict reciprocal control among these enzymes (Stechmiller, 2008). > Arginase signalling plays a vital role in chronic wound pathophysiology and healing. As an evolutionarily conserved enzyme, arginase (ARG) can be expressed in a variety of cells. In the last stage of the urea cycle, arginine protects excess ammonia under homeostatic conditions by producing L-ornithine and urea. L-ornithine is located at the intersection of Arg dependent pathway and urea cycle, contributing to collagen production, cell proliferation and detoxification (Szondi et al., 2021). Collagen is an important component of connective tissue; thus, healing requires collagen formation and deposition (B. Behm, 2012). L-proline is an important collagen building block (Shih et al., 2010).

Notes

  • This provider combines search_papers_by_relevance with snippet_search.
  • No synthesis or second-stage model call is performed.