Transaldolase Deficiency

Mendelian MONDO:0011624 Pathograph 30 Inborn disorder of pentose phosphate metabolism Inborn Error of Metabolism

Transaldolase deficiency is an ultra-rare autosomal recessive inborn error of the pentose phosphate pathway caused by biallelic TALDO1 pathogenic variants. Loss of transaldolase activity disrupts nonoxidative pentose-phosphate metabolism, causing accumulation of polyols and seven-carbon sugars, impaired redox handling, mitochondrial stress, hepatocyte injury, and progressive liver disease. Affected individuals often present antenatally or neonatally with hydrops or edema, hepatosplenomegaly, hepatic dysfunction or cirrhosis, thrombocytopenia, anemia, renal abnormalities, cardiac malformations, abnormal skin vasculature, and variable endocrine or developmental findings. Diagnosis is supported by urinary polyol and sedoheptulose-7-phosphate abnormalities and confirmed by TALDO1 molecular testing. Management is largely supportive, with avoidance of acetaminophen exposure because patients may be unusually vulnerable to oxidative liver injury.

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1
Mappings
1
Definitions
1
Inheritance
5
Pathophys.
19
Phenotypes
1
Hypotheses
30
Pathograph
1
Genes
3
Treatments
10
References
2
Deep Research
1
Hyp. Reports
🔗

Mappings

MONDO
MONDO:0011624 transaldolase deficiency
skos:exactMatch Orphanet ORPHA:101028
Orphanet ORPHA:101028 lists MONDO:0011624 as an exact cross-reference.
📘

Definitions

1
Orphanet transaldolase deficiency definition
Inborn error of the pentose phosphate pathway presenting antenatally or neonatally with hydrops fetalis, hepatosplenomegaly, hepatic dysfunction, thrombocytopenia, anemia, and renal and cardiac abnormalities.
OTHER
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"Transaldolase deficiency is an inborn error of the pentose phosphate pathway"
Orphanet defines the disorder as an inborn pentose-phosphate-pathway error.
PMID:25388407 SUPPORT Human Clinical
"Transaldolase deficiency is a heterogeneous disorder of carbohydrate metabolism"
A patient series independently supports the carbohydrate-metabolism disease framing.
👪

Inheritance

1
Autosomal recessive inheritance HP:0000007
Transaldolase deficiency is inherited in an autosomal recessive pattern.
Autosomal recessive inheritance
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"Autosomal recessive"
Orphanet records autosomal recessive inheritance.
PMID:38440129 SUPPORT Human Clinical
"Transaldolase deficiency is a rare autosomal recessive inborn error"
A clinical case report and review also states autosomal recessive inheritance.
◈

Mechanistic Hypotheses

1
Canonical TALDO1 Pentose-Phosphate Redox Model
canonical_taldo1_ppp_redox_model CANONICAL
Biallelic TALDO1 pathogenic variants abolish or reduce transaldolase function in the nonoxidative pentose phosphate pathway. The resulting seven-carbon sugar and polyol accumulation, NADPH/redox imbalance, and mitochondrial stress promote hepatocyte cell death and progressive liver disease, while toxic metabolite accumulation contributes to renal, cardiac, skin, hematologic, and fetal manifestations.
Retained as CANONICAL. The 2026 openscientist hypothesis-search report (kb/hypotheses/Transaldolase_Deficiency/canonical_taldo1_ppp_redox_model) reviewed 39 papers and found the proximal metabolic-redox mechanism (S7P/polyol accumulation → NADPH/GSH depletion → mitochondrial dysfunction → hepatocyte injury) strongly supported. The NAC rescue experiment in Taldo1-/- mice and successful NAC treatment of TAL- haploinsufficient APAP liver failure patients provide gold-standard causal validation. Three qualifications refine the model: (1) aldose reductase (AR) acts as a metabolic rheostat where its activity diverts carbon to polyols and is required for cirrhosis-to-HCC progression; (2) an mTOR/PON1/antiphospholipid autoantibody axis emerges as a distinct cirrhosis pathway when AR is absent; and (3) the unexplained urinary accumulation of erythronic acid in all patients implicates an uncharacterized biochemical pathway. Extra-hepatic manifestations (renal, cardiac, cutis laxa, hematologic, hydrops) and wide phenotypic variability within identical TALDO1 genotypes remain knowledge gaps.
Deep research
OpenScientist citations 30 citations 2026-05-23T02:08:39.143913
Show evidence (12 references)
PMID:15115436 SUPPORT In Vitro
"deletion of Ser-171 leads to inactivation and proteasome-mediated degradation of TAL-H"
Patient-derived cell and recombinant protein data support enzyme inactivation as a root mechanism.
PMID:17613166 SUPPORT Other
"formation of NADPH for biosynthetic reactions and neutralization of reactive oxygen intermediates"
The pathogenesis review links the pentose phosphate pathway to NADPH-dependent redox control.
PMID:19436114 SUPPORT Model Organism
"Remarkably, lifelong administration of the potent antioxidant N-acetylcysteine (NAC) prevented acetaminophen-induced liver failure, restored Fas-dependent hepatocyte apoptosis, and blocked hepatocarcinogenesis in Taldo1-/- mice."
Gold-standard interventional rescue experiment in Taldo1-/- mice demonstrates that oxidative stress is the proximal driver of liver disease in TAL deficiency: NAC bypasses the NADPH deficit by restoring glutathione synthesis and prevents acetaminophen-induced liver failure and hepatocarcinogenesis.
+ 9 more references
⚙

Pathophysiology

5
TALDO1 transaldolase activity deficiency
Biallelic TALDO1 variants reduce or abolish human transaldolase protein stability and catalytic activity. The Ser171 deletion mechanism shows that mutant transaldolase can be translated but rapidly degraded by the proteasome and lacks appreciable enzymatic activity.
TALDO1 link
transaldolase activity link ↓ DECREASED
Downstream
Reduced transaldolase activity TALDO1 variants reduce or abolish measurable transaldolase enzyme activity.
Pentose phosphate pathway metabolite imbalance Loss of transaldolase activity disrupts nonoxidative pentose-phosphate metabolism.
Show evidence (3 references)
ORPHA:101028 SUPPORT Other
"TALDO1 | transaldolase 1 | hgnc:11559 | Disease-causing germline mutation(s) in"
Orphanet identifies TALDO1 as the disease-causing gene.
PMID:15115436 SUPPORT In Vitro
"Recombinant TALDeltaS171 had no enzymic activity."
Recombinant and patient-cell experiments support loss of transaldolase catalytic activity.
PMID:25388407 SUPPORT Human Clinical
"biallelic mutations in TALDO1 are responsible for transaldolase deficiency"
Human patient data support biallelic TALDO1 mutations as causal.
Pentose phosphate pathway metabolite imbalance
Transaldolase deficiency disrupts the pentose phosphate pathway, causing accumulation of sedoheptulose 7-phosphate and abnormal urinary excretion of polyols and seven-carbon sugars.
pentose phosphate pathway link ⚠ ABNORMAL
Downstream
Redox and mitochondrial stress signaling Pentose-phosphate-pathway imbalance disrupts NADPH and reactive oxygen intermediate handling.
Increased urinary polyols and seven-carbon sugars TALDO deficiency causes diagnostic urinary polyol and seven-carbon sugar abnormalities.
Abnormality of glutamine metabolism The transaldolase metabolic defect is associated with abnormal circulating glutamine concentration.
Abnormality of the kidney Pentose-phosphate metabolite accumulation is associated with renal involvement in transaldolase deficiency.
Hydrops fetalis Severe antenatal transaldolase deficiency can present with hydrops fetalis.
Edema Severe antenatal or neonatal transaldolase deficiency can present with edema.
Abnormal facial shape The multisystem developmental presentation of transaldolase deficiency can include dysmorphic facial features.
Global developmental delay Transaldolase deficiency can include neurodevelopmental delay through incompletely defined intermediates.
Abnormality of the clitoris Transaldolase deficiency is associated with genital developmental abnormalities through unknown intermediates.
Atrial septal defect The multisystem developmental presentation of transaldolase deficiency can include congenital heart disease.
Coarctation of aorta The multisystem developmental presentation of transaldolase deficiency can include congenital aortic disease.
Biventricular hypertrophy Transaldolase deficiency can include cardiac hypertrophy through incompletely defined intermediates.
Abnormal respiratory system physiology Severe multisystem transaldolase deficiency can include respiratory physiology abnormalities.
Premature skin wrinkling The multisystem developmental presentation of transaldolase deficiency can include cutis laxa and premature skin wrinkling through incompletely defined intermediates.
Hypergonadotropic hypogonadism Transaldolase deficiency can include hypergonadotropic hypogonadism through incompletely defined endocrine intermediates.
Show evidence (2 references)
PMID:15115436 SUPPORT In Vitro
"Accumulation of sedoheptulose 7-phosphate raised the possibility of TAL"
Patient-cell biochemical findings support sedoheptulose 7-phosphate accumulation.
PMID:24497183 SUPPORT Human Clinical
"The body fluids of affected patients contain increased polyol concentrations"
The clinical report supports polyol and seven-carbon carbohydrate accumulation.
Redox and mitochondrial stress signaling
The pentose phosphate pathway supplies NADPH for antioxidant defense. Transaldolase-dependent balancing of NADPH and reactive oxygen intermediates influences mitochondrial membrane potential, ATP synthesis, and cell survival; impaired redox handling is implicated in liver injury and acetaminophen sensitivity.
cellular response to oxidative stress link ↑ INCREASED apoptotic process link ↑ INCREASED
Downstream
Hepatocyte apoptosis Oxidative and mitochondrial stress increases hepatocyte cell death.
Show evidence (2 references)
PMID:17613166 SUPPORT Other
"Balancing of NADPH and ROI levels by the PPP enzyme transaldolase"
The review supports transaldolase-dependent NADPH and reactive oxygen intermediate balance.
PMID:29923087 SUPPORT Model Organism
"these hepatic complications are accentuated by oxidative stress related to acetaminophen administration"
Mouse-model evidence links oxidative stress to liver complications in transaldolase deficiency.
Hepatocyte apoptosis
Transaldolase deficiency increases hepatocyte cell death. The cited pathogenesis review links complete human TAL deficiency to cirrhosis through increased hepatocyte cell death, placing hepatocyte apoptosis between redox/mitochondrial stress and chronic liver remodeling.
hepatocyte link
apoptotic process link ↑ INCREASED
Downstream
Hepatic fibrosis and cirrhosis Recurrent hepatocyte injury and cell death promotes progressive hepatic fibrosis and cirrhosis.
Show evidence (1 reference)
PMID:17613166 SUPPORT Human Clinical
"liver cirrhosis which results from increased cell death of hepatocytes"
The review links complete TAL deficiency in patients to increased hepatocyte cell death.
Hepatic fibrosis and cirrhosis
Ongoing liver injury in transaldolase deficiency produces progressive nodular hepatic fibrosis and cirrhosis. This chronic liver remodeling explains major liver-centered consequences, including hepatosplenomegaly, cytopenias, bleeding tendency, and skin vascular changes associated with liver damage.
Downstream
Cirrhosis Hepatocyte injury and fibrosis produce cirrhosis.
Hepatosplenomegaly Severe liver-centered transaldolase deficiency is associated with hepatosplenomegaly, but the cached evidence does not specify the intermediate mechanism.
Thrombocytopenia Severe liver-centered transaldolase deficiency is associated with thrombocytopenia, but the cached evidence does not specify the intermediate mechanism.
Anemia Severe liver-centered transaldolase deficiency is associated with anemia, but the cached evidence does not specify the intermediate mechanism.
Telangiectasia Liver damage is associated with spider angiomas and visible skin vessels.
Increased serum bile acid concentration Hepatic dysfunction in transaldolase deficiency is associated with increased serum bile acids.
Show evidence (2 references)
PMID:17613166 SUPPORT Human Clinical
"liver cirrhosis which results from increased cell death of hepatocytes"
The review supports cirrhosis as the downstream consequence of hepatocyte cell death.
PMID:24497183 SUPPORT Human Clinical
"rapidly progressive nodular liver fibrosis, tubulopathy and severe clotting disturbances"
Patient reports support progressive hepatic fibrosis and systemic consequences.
⬡

Pathograph

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

19
Blood 2
Thrombocytopenia VERY_FREQUENT Thrombocytopenia (HP:0001873)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0001873 | Thrombocytopenia | Very frequent (99-80%)"
Orphanet records thrombocytopenia as a very frequent phenotype.
PMID:24497183 SUPPORT Human Clinical
"hepatosplenomegaly, thrombocytopenia, anaemia, bleeding diathesis, liver failure"
The clinical report supports thrombocytopenia in affected patients.
Anemia VERY_FREQUENT Anemia (HP:0001903)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0001903 | Anemia | Very frequent (99-80%)"
Orphanet records anemia as a very frequent phenotype.
PMID:24497183 SUPPORT Human Clinical
"hepatosplenomegaly, thrombocytopenia, anaemia, bleeding diathesis, liver failure"
The clinical report supports anemia in affected patients.
Cardiovascular 4
Hepatosplenomegaly VERY_FREQUENT Hepatosplenomegaly (HP:0001433)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0001433 | Hepatosplenomegaly | Very frequent (99-80%)"
Orphanet records hepatosplenomegaly as a very frequent phenotype.
PMID:25388407 SUPPORT Human Clinical
"The patients had variable clinical presentations including hepatosplenomegaly"
Patient-level evidence supports hepatosplenomegaly.
Telangiectasia FREQUENT Telangiectasia (HP:0001009)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0001009 | Telangiectasia | Frequent (79-30%)"
Orphanet records telangiectasia as frequent.
PMID:25388407 SUPPORT Human Clinical
"skin manifestations (e.g., dryness, cutis laxa, ichthyosis, telangiectasias, and hemangiomas)."
Patient-series abstract supports telangiectasias.
Atrial septal defect OCCASIONAL Atrial septal defect (HP:0001631)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0001631 | Atrial septal defect | Occasional (29-5%)"
Orphanet records atrial septal defect as occasional.
Coarctation of aorta OCCASIONAL Coarctation of aorta (HP:0001680)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0001680 | Coarctation of aorta | Occasional (29-5%)"
Orphanet records coarctation of aorta as occasional.
Digestive 1
Cirrhosis VERY_FREQUENT Cirrhosis (HP:0001394)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0001394 | Cirrhosis | Very frequent (99-80%)"
Orphanet records cirrhosis as a very frequent phenotype.
PMID:18331807 SUPPORT Human Clinical
"subsequently found to have cirrhosis and deafness"
The clinical report documents cirrhosis in a child with TALDO deficiency.
Endocrine 1
Hypergonadotropic hypogonadism OCCASIONAL Hypergonadotropic hypogonadism (HP:0000815)
Show evidence (2 references)
PMID:38440129 SUPPORT Human Clinical
"two Emirati patients with hypergonadotropic hypogonadism due to transaldolase deficiency"
The case report directly documents hypergonadotropic hypogonadism in transaldolase deficiency.
PMID:33159679 SUPPORT Human Clinical
"deficiency characterized by hypergonadotropic hypogonadism and slightly elevated"
A late-onset patient report supports hypergonadotropic hypogonadism as a variable manifestation.
Genitourinary 1
Abnormality of the kidney FREQUENT Abnormality of the kidney (HP:0000077)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0000077 | Abnormality of the kidney | Frequent (79-30%)"
Orphanet records kidney abnormality as frequent.
PMID:25388407 SUPPORT Human Clinical
"renal and cardiac abnormalities, and urinary excretion of polyols."
Patient-series abstract supports renal abnormalities in the disorder.
Head and Neck 1
Abnormal facial shape FREQUENT Abnormal facial shape (HP:0001999)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0001999 | Abnormal facial shape | Frequent (79-30%)"
Orphanet records abnormal facial shape as frequent.
PMID:23315216 SUPPORT Human Clinical
"growth retardation, dysmorphic features, cutis laxa, congenital heart disease"
The 12-case series supports dysmorphic features.
Metabolism 2
Edema FREQUENT Edema (HP:0000969)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0000969 | Edema | Frequent (79-30%)"
Orphanet records edema as frequent.
Hydrops fetalis FREQUENT Hydrops fetalis (HP:0001789)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0001789 | Hydrops fetalis | Frequent (79-30%)"
Orphanet records hydrops fetalis as frequent.
PMID:25388407 SUPPORT Human Clinical
"proteinuria, hydrops fetalis, cardiomyopathy, and skin manifestations"
Patient-series abstract supports hydrops fetalis.
Nervous System 1
Global developmental delay OCCASIONAL Global developmental delay (HP:0001263)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0001263 | Global developmental delay | Occasional (29-5%)"
Orphanet records global developmental delay as occasional.
Respiratory 1
Abnormal respiratory system physiology OCCASIONAL Abnormal respiratory system physiology (HP:0002795)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0002795 | Abnormal respiratory system physiology | Occasional (29-5%)"
Orphanet records respiratory physiology abnormality as occasional.
Other 5
Abnormality of glutamine metabolism VERY_FREQUENT Abnormal circulating glutamine concentration (HP:0010903)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0010903 | Abnormality of glutamine metabolism | Very frequent (99-80%)"
Orphanet records abnormal glutamine metabolism as very frequent.
Increased serum bile acid concentration VERY_FREQUENT Increased serum bile acid concentration (HP:0012202)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0012202 | Increased serum bile acid concentration | Very frequent (99-80%)"
Orphanet records increased serum bile acids as very frequent.
Abnormality of the clitoris FREQUENT Abnormal clitoris morphology (HP:0000056)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0000056 | Abnormality of the clitoris | Frequent (79-30%)"
Orphanet records clitoral abnormality as frequent.
Premature skin wrinkling FREQUENT Premature skin wrinkling (HP:0100678)
Show evidence (2 references)
ORPHA:101028 SUPPORT Other
"HP:0100678 | Premature skin wrinkling | Frequent (79-30%)"
Orphanet records premature skin wrinkling as frequent.
PMID:23315216 SUPPORT Human Clinical
"growth retardation, dysmorphic features, cutis laxa, congenital heart disease"
The 12-case series supports cutis laxa and abnormal skin findings.
Biventricular hypertrophy OCCASIONAL Biventricular hypertrophy (HP:0200128)
Show evidence (1 reference)
ORPHA:101028 SUPPORT Other
"HP:0200128 | Biventricular hypertrophy | Occasional (29-5%)"
Orphanet records biventricular hypertrophy as occasional.
🧬

Genetic Associations

1
Biallelic TALDO1 pathogenic variants (Causative)
Autosomal recessive inheritance
Show evidence (3 references)
ORPHA:101028 SUPPORT Other
"TALDO1 | transaldolase 1 | hgnc:11559 | Disease-causing germline mutation(s) in"
Orphanet records TALDO1 as disease-causing.
PMID:23315216 SUPPORT Human Clinical
"sequencing confirmed segregation of a novel homozygous mutation with the disease"
Segregation in affected families supports recessive TALDO1 causality.
PMID:38440129 SUPPORT Human Clinical
"caused by pathogenic/likely pathogenic biallelic mutations in the TALDO1 gene"
Recent clinical review supports biallelic TALDO1 variants as the molecular cause.
💊

Treatments

3
Supportive management and acetaminophen avoidance
Action: supportive care MAXO:0000950
Disease-specific management is supportive and should include avoidance of acetaminophen because clinical and model evidence indicates increased vulnerability to acetaminophen-related oxidative liver injury.
Mechanism Target:
MODULATES Redox and mitochondrial stress signaling — Acetaminophen avoidance reduces exposure to a trigger that can accentuate oxidative liver stress in transaldolase deficiency.
Show evidence (1 reference)
PMID:29923087 SUPPORT Human Clinical
"transaldolase-deficient patients are uniquely sensitive to acetaminophen and should avoid this antipyretic."
The human case report supports avoidance of acetaminophen as a way to reduce oxidative liver-injury risk.
Show evidence (2 references)
PMID:24497183 SUPPORT Human Clinical
"Symptomatic treatment can be proposed."
The clinical report states that symptomatic treatment can be proposed.
PMID:29923087 SUPPORT Human Clinical
"transaldolase-deficient patients are uniquely sensitive to acetaminophen and should avoid this antipyretic."
A human case and supporting model evidence support acetaminophen avoidance.
N-acetylcysteine for oxidative liver stress
Action: Pharmacotherapy NCIT:C15986
Agent: N-acetyl-L-cysteine ↗
N-acetylcysteine has model-organism support for preventing acetaminophen- induced liver failure and limited human observational support for lowering alpha-fetoprotein, so it is recorded as a context-specific antioxidant option rather than established disease-modifying therapy.
Mechanism Target:
MODULATES Redox and mitochondrial stress signaling — N-acetylcysteine is an antioxidant intended to reduce oxidative liver stress.
Show evidence (1 reference)
PMID:29923087 SUPPORT Model Organism
"acetaminophen-induced liver failure can be prevented by administration of the antioxidant N-acetylcysteine."
Mouse-model evidence supports an antioxidant rescue mechanism.
Show evidence (1 reference)
PMID:29923087 PARTIAL Human Clinical
"treatment of a transaldolase-deficient patient with N-acetylcysteine was associated with a decrease"
Published human experience provides limited supportive evidence for NAC use.
Liver transplantation consideration
Action: organ transplantation MAXO:0010039
Early liver transplantation has been proposed for severe progressive liver disease, but the available cached evidence is cautious and not sufficient to establish benefit.
Mechanism Target:
MODULATES Hepatic fibrosis and cirrhosis — Liver transplantation has been proposed as a possible intervention for early severe liver disease, but the evidence remains tentative.
Show evidence (1 reference)
PMID:24497183 PARTIAL Human Clinical
"Liver transplantation in the early stage of the disease could perhaps be useful."
The report proposes transplantation for severe liver disease but does not establish efficacy.
Show evidence (1 reference)
PMID:24497183 PARTIAL Human Clinical
"Liver transplantation in the early stage of the disease could perhaps be useful."
The report proposes liver transplantation as a possible option but does not prove efficacy.
🔬

Biochemical Markers

2
Reduced transaldolase activity (DECREASED)
Context: Patient-derived fibroblast and lymphoblast studies and recombinant protein assays show loss of transaldolase enzymatic activity in disease-associated TALDO1 variants.
Pathograph Readouts
Readout Of TALDO1 transaldolase activity deficiency Negative Diagnostic
Reduced transaldolase enzyme activity directly reports the primary TALDO1 catalytic-function defect.
Show evidence (1 reference)
PMID:15115436 SUPPORT In Vitro
"no expression of the TALDeltaS171 protein or enzyme activity was detected"
Patient-cell experiments show absent transaldolase protein/enzyme activity, supporting enzyme activity as a direct readout of the root mechanism.
Show evidence (1 reference)
PMID:15115436 SUPPORT In Vitro
"no expression of the TALDeltaS171 protein or enzyme activity was detected"
Patient-cell experiments support reduced transaldolase activity as the primary biochemical defect.
Increased urinary polyols and seven-carbon sugars (INCREASED)
Context: Urine testing shows increased erythritol, ribitol, arabitol, sedoheptitol, perseitol, sedoheptulose, and sedoheptulose-7-phosphate, supporting the biochemical diagnosis.
Pathograph Readouts
Readout Of Pentose phosphate pathway metabolite imbalance Positive Diagnostic
Increased urinary polyols and seven-carbon sugars report the downstream pentose-phosphate metabolite imbalance caused by transaldolase deficiency.
Show evidence (1 reference)
PMID:24497183 SUPPORT Human Clinical
"Elevated excretion of erythritol, ribitol, arabitol, sedoheptitol, perseitol, sedoheptulose and sedoheptulose-7P in the urine"
Human urine testing directly supports the metabolite panel as a diagnostic readout of the pentose-phosphate metabolite imbalance.
Show evidence (2 references)
PMID:24497183 SUPPORT Human Clinical
"Elevated excretion of erythritol, ribitol, arabitol, sedoheptitol, perseitol, sedoheptulose and sedoheptulose-7P in the urine"
The patient report provides the diagnostic urinary metabolite pattern.
PMID:29923087 SUPPORT Human Clinical
"Urine polyols and plasma metabolomics confirmed the diagnosis of transaldolase deficiency."
Human metabolomics data support urine polyols as diagnostic biochemical evidence.
{ }

Source YAML

click to show 
name: Transaldolase Deficiency
creation_date: "2026-05-05T07:40:18Z"
updated_date: "2026-05-21T07:21:36Z"
category: Mendelian
synonyms:
- TALDO deficiency
- Eyaid syndrome
description: >
  Transaldolase deficiency is an ultra-rare autosomal recessive inborn error of
  the pentose phosphate pathway caused by biallelic TALDO1 pathogenic variants.
  Loss of transaldolase activity disrupts nonoxidative pentose-phosphate
  metabolism, causing accumulation of polyols and seven-carbon sugars,
  impaired redox handling, mitochondrial stress, hepatocyte injury, and
  progressive liver disease. Affected individuals often present antenatally or
  neonatally with hydrops or edema, hepatosplenomegaly, hepatic dysfunction or
  cirrhosis, thrombocytopenia, anemia, renal abnormalities, cardiac
  malformations, abnormal skin vasculature, and variable endocrine or
  developmental findings. Diagnosis is supported by urinary polyol and
  sedoheptulose-7-phosphate abnormalities and confirmed by TALDO1 molecular
  testing. Management is largely supportive, with avoidance of acetaminophen
  exposure because patients may be unusually vulnerable to oxidative
  liver injury.
disease_term:
  preferred_term: transaldolase deficiency
  term:
    id: MONDO:0011624
    label: transaldolase deficiency
parents:
- Inborn disorder of pentose phosphate metabolism
- Inborn Error of Metabolism
notes: >-
  ORPHA:101028 maps Transaldolase deficiency exactly to MONDO:0011624 and
  OMIM:606003, lists TALDO1 as the disease-causing gene, and records
  antenatal, neonatal, and infancy onset.
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0011624
      label: transaldolase deficiency
    mapping_predicate: skos:exactMatch
    mapping_source: Orphanet ORPHA:101028
    mapping_justification: Orphanet ORPHA:101028 lists MONDO:0011624 as an exact cross-reference.
external_assertions:
- name: Orphanet Transaldolase deficiency disease record
  source: Orphanet
  assertion_type: structured_disease_record
  external_id: ORPHA:101028
  url: http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=101028
  description: >
    Orphanet's ORPHA:101028 structured record for Transaldolase deficiency
    provides the disease definition, autosomal recessive inheritance, TALDO1
    disease-causing gene association, point-prevalence estimate, onset
    categories, exact MONDO/OMIM cross-references, and HPO phenotype
    frequencies used in this entry.
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "MONDO:0011624 | Exact"
    explanation: Orphanet maps ORPHA:101028 exactly to the MONDO term used here.
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "OMIM:606003 | Exact"
    explanation: Orphanet lists OMIM:606003 as an exact external cross-reference.
definitions:
- name: Orphanet transaldolase deficiency definition
  definition_type: OTHER
  description: >
    Inborn error of the pentose phosphate pathway presenting antenatally or
    neonatally with hydrops fetalis, hepatosplenomegaly, hepatic dysfunction,
    thrombocytopenia, anemia, and renal and cardiac abnormalities.
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Transaldolase deficiency is an inborn error of the pentose phosphate pathway"
    explanation: Orphanet defines the disorder as an inborn pentose-phosphate-pathway error.
  - reference: PMID:25388407
    reference_title: "Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Transaldolase deficiency is a heterogeneous disorder of carbohydrate metabolism"
    explanation: A patient series independently supports the carbohydrate-metabolism disease framing.
inheritance:
- name: Autosomal recessive inheritance
  description: Transaldolase deficiency is inherited in an autosomal recessive pattern.
  inheritance_term:
    preferred_term: Autosomal recessive inheritance
    term:
      id: HP:0000007
      label: Autosomal recessive inheritance
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Autosomal recessive"
    explanation: Orphanet records autosomal recessive inheritance.
  - reference: PMID:38440129
    reference_title: "Hypergonadotropic Hypogonadism Due to Transaldolase Deficiency: Two Cases and Literature Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Transaldolase deficiency is a rare autosomal recessive inborn error"
    explanation: A clinical case report and review also states autosomal recessive inheritance.
prevalence:
- population: Worldwide
  percentage: <1 per 1,000,000
  notes: Orphanet records worldwide point prevalence below 1 per 1,000,000.
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "<1 / 1 000 000 | Worldwide | Point prevalence | PMID:23315216"
    explanation: Orphanet provides the worldwide point-prevalence estimate.
progression:
- phase: Antenatal-to-neonatal multisystem presentation
  age_range: Antenatal, neonatal, or infancy
  notes: >
    Orphanet records antenatal, neonatal, and infancy onset. Published cohorts
    describe prenatal growth and fluid abnormalities and neonatal anemia,
    thrombocytopenia, hepatosplenomegaly, liver involvement, renal disease,
    and later variable endocrine presentations.
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Age of onset: Antenatal"
    explanation: Orphanet records antenatal onset.
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Age of onset: Neonatal"
    explanation: Orphanet records neonatal onset.
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients present severe symptoms during the neonatal period"
    explanation: The clinical report supports typical severe neonatal presentation.
mechanistic_hypotheses:
- hypothesis_group_id: canonical_taldo1_ppp_redox_model
  hypothesis_label: Canonical TALDO1 Pentose-Phosphate Redox Model
  status: CANONICAL
  description: >
    Biallelic TALDO1 pathogenic variants abolish or reduce transaldolase
    function in the nonoxidative pentose phosphate pathway. The resulting
    seven-carbon sugar and polyol accumulation, NADPH/redox imbalance, and
    mitochondrial stress promote hepatocyte cell death and progressive liver
    disease, while toxic metabolite accumulation contributes to renal, cardiac,
    skin, hematologic, and fetal manifestations.
  notes: >-
    Retained as CANONICAL. The 2026 openscientist hypothesis-search report
    (kb/hypotheses/Transaldolase_Deficiency/canonical_taldo1_ppp_redox_model)
    reviewed 39 papers and found the proximal metabolic-redox mechanism
    (S7P/polyol accumulation → NADPH/GSH depletion → mitochondrial
    dysfunction → hepatocyte injury) strongly supported. The NAC rescue
    experiment in Taldo1-/- mice and successful NAC treatment of TAL-
    haploinsufficient APAP liver failure patients provide gold-standard
    causal validation. Three qualifications refine the model: (1) aldose
    reductase (AR) acts as a metabolic rheostat where its activity diverts
    carbon to polyols and is required for cirrhosis-to-HCC progression; (2)
    an mTOR/PON1/antiphospholipid autoantibody axis emerges as a distinct
    cirrhosis pathway when AR is absent; and (3) the unexplained urinary
    accumulation of erythronic acid in all patients implicates an
    uncharacterized biochemical pathway. Extra-hepatic manifestations
    (renal, cardiac, cutis laxa, hematologic, hydrops) and wide
    phenotypic variability within identical TALDO1 genotypes remain
    knowledge gaps.
  evidence:
  - reference: PMID:15115436
    reference_title: "Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "deletion of Ser-171 leads to inactivation and proteasome-mediated degradation of TAL-H"
    explanation: Patient-derived cell and recombinant protein data support enzyme inactivation as a root mechanism.
  - reference: PMID:17613166
    reference_title: "The pathogenesis of transaldolase deficiency."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "formation of NADPH for biosynthetic reactions and neutralization of reactive oxygen intermediates"
    explanation: The pathogenesis review links the pentose phosphate pathway to NADPH-dependent redox control.
  - reference: PMID:19436114
    reference_title: "Prevention of hepatocarcinogenesis and increased susceptibility to acetaminophen-induced liver failure in transaldolase-deficient mice by N-acetylcysteine."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Remarkably, lifelong administration of the potent antioxidant N-acetylcysteine (NAC) prevented acetaminophen-induced liver failure, restored Fas-dependent hepatocyte apoptosis, and blocked hepatocarcinogenesis in Taldo1-/- mice."
    explanation: >
      Gold-standard interventional rescue experiment in Taldo1-/- mice
      demonstrates that oxidative stress is the proximal driver of liver
      disease in TAL deficiency: NAC bypasses the NADPH deficit by
      restoring glutathione synthesis and prevents acetaminophen-induced
      liver failure and hepatocarcinogenesis.
  - reference: PMID:18498245
    reference_title: "Transaldolase deficiency influences the pentose phosphate pathway, mitochondrial homoeostasis and apoptosis signal processing."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Sedoheptulose 7-phosphate was accumulated, whereas G6P (glucose 6-phosphate) was depleted, indicating a failure to recycle G6P for the oxidative branch of the PPP."
    explanation: >
      Patient-derived TAL-deficient lymphoblasts directly demonstrate S7P
      accumulation and G6P depletion, NADPH/NAD+ depletion, mitochondrial
      dysfunction, and increased apoptosis, validating the carbon-trapping
      and redox-failure steps of the canonical model in human cells.
  - reference: PMID:16470722
    reference_title: "Study of transaldolase deficiency in urine samples by capillary LC-MS/MS."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Sedoheptulose 7-phosphate (S7P), C5-polyols D-arabitol and D-ribitol, and 6-phosphogluconate (6PG) levels were markedly increased in urine of TAL-deficient mice"
    explanation: >
      Urinary metabolomics from Taldo1-/- mice confirms that loss of
      transaldolase activity leads to PPP blockade with characteristic
      accumulation of S7P, C5-polyols, and 6PG that match human patient
      biomarker profiles.
  - reference: PMID:17003133
    reference_title: "Transaldolase is essential for maintenance of the mitochondrial transmembrane potential and fertility of spermatozoa."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Stimulation of de novo GSH synthesis by oral N-acetyl-cysteine normalized the low fertility rate of TAL(+/-) males"
    explanation: >
      Independent NAC rescue experiment in a non-hepatic tissue
      (testis/sperm) shows that GSH depletion downstream of TAL deficiency
      causes tissue-specific mitochondrial dysfunction, supporting the
      generality of the redox-stress mechanism across organs.
  - reference: PMID:31769880
    reference_title: "Transaldolase haploinsufficiency in subjects with acetaminophen-induced liver failure."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "haplo-insufficiency with APAP-induced liver failure were successfully treated"
    explanation: >
      Direct human translational validation: four TAL-haploinsufficient
      adults with acetaminophen-induced liver failure recovered fully on
      NAC, providing clinical evidence that the mouse-model NAC rescue
      generalizes to humans with partial TAL deficiency.
  - reference: PMID:36658399
    reference_title: "Aldose reductase rewires metabolism and protects from acetaminophen-induced hepatocyte injury and hepatocellular carcinoma in transaldolase deficiency."
    supports: PARTIAL
    evidence_source: MODEL_ORGANISM
    snippet: "mitochondrial oxidative stress and progression from cirrhosis to HCC and acetaminophen-induced liver necrosis are critically dependent on NADPH depletion and polyol buildup by aldose reductase"
    explanation: >
      Qualifies the canonical model with the AR rheostat mechanism: AR
      activity diverts trapped seven-carbon sugars to polyols, preventing
      carbon trapping but consuming NADPH and driving HCC progression.
      Cirrhosis and HCC have partially distinct metabolic drivers, refining
      the linear canonical chain.
  - reference: PMID:37742509
    reference_title: "Sustained mTOR activation triggers autoimmune cirrhosis upon inactivation of the transaldolase-aldose reductase axis."
    supports: PARTIAL
    evidence_source: MODEL_ORGANISM
    snippet: "inactivation of the TAL-AR axis results in metabolic stress characterized by reduced mitophagy, enhanced overall autophagy, activation of the mechanistic target of rapamycin (mTOR), diminished glycosylation and secretion of paraoxonase 1 (PON1), production of antiphospholipid autoantibodies"
    explanation: >
      Qualifies the canonical model by demonstrating a parallel mTOR/PON1/
      autoimmune cirrhosis pathway unmasked in TAL-/- AR-/- compound
      knockout mice. This emerging mechanism may contribute to the cirrhosis
      phenotype in a subset of TAL-deficient patients but human relevance
      is currently unknown.
  - reference: PMID:20600873
    reference_title: "Erythronic acid is a major metabolite in transaldolase deficiency."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "erythronic acid ranks among the key metabolic features in TALDO deficiency and testifies a high flux through an as yet unknown metabolic pathway"
    explanation: >
      Qualifies the canonical model by identifying erythronic acid
      accumulation in all TAL-deficient patients and Taldo1-/- mice as a
      hallmark biomarker that implicates an uncharacterized biochemical
      pathway, beyond the canonical S7P/polyol overflow.
  - reference: PMID:25388407
    reference_title: "Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "four Emirati patients with transaldolase deficiency caused by the homozygous p.R192C missense mutation in TALDO1 displaying wide phenotypic variability"
    explanation: >
      Qualifies the canonical model by demonstrating wide phenotypic
      variability (hydrops fetalis to relatively mild disease) within
      patients sharing identical p.R192C TALDO1 genotypes, implicating
      modifier genes, epigenetic factors, or environmental exposures not
      captured by the simple linear model.
  - reference: PMID:34677006
    reference_title: "Transaldolase deficiency: A new cause of hepatocellular carcinoma in children."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Three patients underwent liver transplantation (LT), 2 of whom had confirmed HCC on explanted liver"
    explanation: >
      Pediatric clinical cohort confirms early-onset hepatocellular
      carcinoma as a clinical endpoint of TAL deficiency, supporting the
      canonical model's prediction that PPP/redox failure drives hepatic
      neoplastic progression.
pathophysiology:
- name: TALDO1 transaldolase activity deficiency
  description: >
    Biallelic TALDO1 variants reduce or abolish human transaldolase protein
    stability and catalytic activity. The Ser171 deletion mechanism shows that
    mutant transaldolase can be translated but rapidly degraded by the
    proteasome and lacks appreciable enzymatic activity.
  genes:
  - preferred_term: TALDO1
    term:
      id: hgnc:11559
      label: TALDO1
  molecular_functions:
  - preferred_term: transaldolase activity
    modifier: DECREASED
    term:
      id: GO:0004801
      label: transaldolase activity
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "TALDO1 | transaldolase 1 | hgnc:11559 | Disease-causing germline mutation(s) in"
    explanation: Orphanet identifies TALDO1 as the disease-causing gene.
  - reference: PMID:15115436
    reference_title: "Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Recombinant TALDeltaS171 had no enzymic activity."
    explanation: Recombinant and patient-cell experiments support loss of transaldolase catalytic activity.
  - reference: PMID:25388407
    reference_title: "Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "biallelic mutations in TALDO1 are responsible for transaldolase deficiency"
    explanation: Human patient data support biallelic TALDO1 mutations as causal.
  downstream:
  - target: Reduced transaldolase activity
    description: TALDO1 variants reduce or abolish measurable transaldolase enzyme activity.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:15115436
      reference_title: "Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "Recombinant TALDeltaS171 had no enzymic activity."
      explanation: Recombinant mutant transaldolase experiments directly support loss of enzyme activity.
  - target: Pentose phosphate pathway metabolite imbalance
    description: Loss of transaldolase activity disrupts nonoxidative pentose-phosphate metabolism.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:15115436
      reference_title: "Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "Accumulation of sedoheptulose 7-phosphate raised the possibility of TAL"
      explanation: Patient-cell biochemical findings link TAL deficiency to sedoheptulose-7-phosphate accumulation.
- name: Pentose phosphate pathway metabolite imbalance
  description: >
    Transaldolase deficiency disrupts the pentose phosphate pathway, causing
    accumulation of sedoheptulose 7-phosphate and abnormal urinary excretion of
    polyols and seven-carbon sugars.
  biological_processes:
  - preferred_term: pentose phosphate pathway
    modifier: ABNORMAL
    term:
      id: GO:0006098
      label: pentose-phosphate shunt
  chemical_entities:
  - preferred_term: sedoheptulose 7-phosphate
    modifier: INCREASED
    term:
      id: CHEBI:57483
      label: sedoheptulose 7-phosphate(2-)
  evidence:
  - reference: PMID:15115436
    reference_title: "Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Accumulation of sedoheptulose 7-phosphate raised the possibility of TAL"
    explanation: Patient-cell biochemical findings support sedoheptulose 7-phosphate accumulation.
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The body fluids of affected patients contain increased polyol concentrations"
    explanation: The clinical report supports polyol and seven-carbon carbohydrate accumulation.
  downstream:
  - target: Redox and mitochondrial stress signaling
    description: Pentose-phosphate-pathway imbalance disrupts NADPH and reactive oxygen intermediate handling.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:17613166
      reference_title: "The pathogenesis of transaldolase deficiency."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Balancing of NADPH and ROI levels by the PPP enzyme transaldolase"
      explanation: The pathogenesis review directly links transaldolase to PPP-dependent NADPH and reactive oxygen intermediate balance.
  - target: Increased urinary polyols and seven-carbon sugars
    description: TALDO deficiency causes diagnostic urinary polyol and seven-carbon sugar abnormalities.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:24497183
      reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Elevated excretion of erythritol, ribitol, arabitol, sedoheptitol, perseitol, sedoheptulose and sedoheptulose-7P in the urine"
      explanation: Human patient urine testing directly supports the diagnostic seven-carbon sugar and polyol endpoint.
  - target: Abnormality of glutamine metabolism
    description: The transaldolase metabolic defect is associated with abnormal circulating glutamine concentration.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0010903 | Abnormality of glutamine metabolism | Very frequent (99-80%)"
      explanation: Orphanet records abnormal glutamine metabolism as a very frequent transaldolase deficiency phenotype.
  - target: Abnormality of the kidney
    description: Pentose-phosphate metabolite accumulation is associated with renal involvement in transaldolase deficiency.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Toxic effects of accumulated sugars, sugar phosphates, and polyols on proximal tubules.
    evidence:
    - reference: PMID:24497183
      reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The development of tubulopathy and, in the case of the second patient, nephrolithiasis is probably due to the toxic effect of sugars, sugar phosphates and polyols on the proximal tubules"
      explanation: The full-text clinical report links accumulated metabolites to renal tubulopathy.
  - target: Hydrops fetalis
    description: Severe antenatal transaldolase deficiency can present with hydrops fetalis.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0001789 | Hydrops fetalis | Frequent (79-30%)"
      explanation: Orphanet records hydrops fetalis as a frequent phenotype.
  - target: Edema
    description: Severe antenatal or neonatal transaldolase deficiency can present with edema.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0000969 | Edema | Frequent (79-30%)"
      explanation: Orphanet records edema as a frequent phenotype.
  - target: Abnormal facial shape
    description: The multisystem developmental presentation of transaldolase deficiency can include dysmorphic facial features.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:23315216
      reference_title: "Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "growth retardation, dysmorphic features, cutis laxa, congenital heart disease"
      explanation: The 12-case clinical series reports dysmorphic features in transaldolase deficiency.
  - target: Global developmental delay
    description: Transaldolase deficiency can include neurodevelopmental delay through incompletely defined intermediates.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0001263 | Global developmental delay | Occasional (29-5%)"
      explanation: Orphanet records global developmental delay as an occasional phenotype.
  - target: Abnormality of the clitoris
    description: Transaldolase deficiency is associated with genital developmental abnormalities through unknown intermediates.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0000056 | Abnormality of the clitoris | Frequent (79-30%)"
      explanation: Orphanet records clitoral abnormality as a frequent phenotype.
  - target: Atrial septal defect
    description: The multisystem developmental presentation of transaldolase deficiency can include congenital heart disease.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0001631 | Atrial septal defect | Occasional (29-5%)"
      explanation: Orphanet records atrial septal defect as an occasional phenotype.
  - target: Coarctation of aorta
    description: The multisystem developmental presentation of transaldolase deficiency can include congenital aortic disease.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0001680 | Coarctation of aorta | Occasional (29-5%)"
      explanation: Orphanet records coarctation of aorta as an occasional phenotype.
  - target: Biventricular hypertrophy
    description: Transaldolase deficiency can include cardiac hypertrophy through incompletely defined intermediates.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0200128 | Biventricular hypertrophy | Occasional (29-5%)"
      explanation: Orphanet records biventricular hypertrophy as an occasional phenotype.
  - target: Abnormal respiratory system physiology
    description: Severe multisystem transaldolase deficiency can include respiratory physiology abnormalities.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0002795 | Abnormal respiratory system physiology | Occasional (29-5%)"
      explanation: Orphanet records respiratory physiology abnormality as an occasional phenotype.
  - target: Premature skin wrinkling
    description: The multisystem developmental presentation of transaldolase deficiency can include cutis laxa and premature skin wrinkling through incompletely defined intermediates.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:23315216
      reference_title: "Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "growth retardation, dysmorphic features, cutis laxa, congenital heart disease"
      explanation: The 12-case series supports cutis laxa/skin changes in the multisystem presentation.
  - target: Hypergonadotropic hypogonadism
    description: Transaldolase deficiency can include hypergonadotropic hypogonadism through incompletely defined endocrine intermediates.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:38440129
      reference_title: "Hypergonadotropic Hypogonadism Due to Transaldolase Deficiency: Two Cases and Literature Review."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "two Emirati patients with hypergonadotropic hypogonadism due to transaldolase deficiency"
      explanation: The case report directly documents hypergonadotropic hypogonadism in transaldolase deficiency.
- name: Redox and mitochondrial stress signaling
  description: >
    The pentose phosphate pathway supplies NADPH for antioxidant defense.
    Transaldolase-dependent balancing of NADPH and reactive oxygen intermediates
    influences mitochondrial membrane potential, ATP synthesis, and cell
    survival; impaired redox handling is implicated in liver injury and
    acetaminophen sensitivity.
  biological_processes:
  - preferred_term: cellular response to oxidative stress
    modifier: INCREASED
    term:
      id: GO:0034599
      label: cellular response to oxidative stress
  - preferred_term: apoptotic process
    modifier: INCREASED
    term:
      id: GO:0006915
      label: apoptotic process
  chemical_entities:
  - preferred_term: NADPH
    modifier: ABNORMAL
    term:
      id: CHEBI:16474
      label: NADPH
  evidence:
  - reference: PMID:17613166
    reference_title: "The pathogenesis of transaldolase deficiency."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Balancing of NADPH and ROI levels by the PPP enzyme transaldolase"
    explanation: The review supports transaldolase-dependent NADPH and reactive oxygen intermediate balance.
  - reference: PMID:29923087
    reference_title: "Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "these hepatic complications are accentuated by oxidative stress related to acetaminophen administration"
    explanation: Mouse-model evidence links oxidative stress to liver complications in transaldolase deficiency.
  downstream:
  - target: Hepatocyte apoptosis
    description: Oxidative and mitochondrial stress increases hepatocyte cell death.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:17613166
      reference_title: "The pathogenesis of transaldolase deficiency."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "liver cirrhosis which results from increased cell death of hepatocytes"
      explanation: The pathogenesis review links TAL deficiency in patients to increased hepatocyte cell death leading to cirrhosis.
- name: Hepatocyte apoptosis
  description: >
    Transaldolase deficiency increases hepatocyte cell death. The cited
    pathogenesis review links complete human TAL deficiency to cirrhosis
    through increased hepatocyte cell death, placing hepatocyte apoptosis
    between redox/mitochondrial stress and chronic liver remodeling.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  biological_processes:
  - preferred_term: apoptotic process
    modifier: INCREASED
    term:
      id: GO:0006915
      label: apoptotic process
  evidence:
  - reference: PMID:17613166
    reference_title: "The pathogenesis of transaldolase deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "liver cirrhosis which results from increased cell death of hepatocytes"
    explanation: The review links complete TAL deficiency in patients to increased hepatocyte cell death.
  downstream:
  - target: Hepatic fibrosis and cirrhosis
    description: Recurrent hepatocyte injury and cell death promotes progressive hepatic fibrosis and cirrhosis.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:17613166
      reference_title: "The pathogenesis of transaldolase deficiency."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "liver cirrhosis which results from increased cell death of hepatocytes"
      explanation: This directly supports cirrhosis downstream of increased hepatocyte cell death.
- name: Hepatic fibrosis and cirrhosis
  description: >
    Ongoing liver injury in transaldolase deficiency produces progressive
    nodular hepatic fibrosis and cirrhosis. This chronic liver remodeling
    explains major liver-centered consequences, including hepatosplenomegaly,
    cytopenias, bleeding tendency, and skin vascular changes associated with
    liver damage.
  evidence:
  - reference: PMID:17613166
    reference_title: "The pathogenesis of transaldolase deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "liver cirrhosis which results from increased cell death of hepatocytes"
    explanation: The review supports cirrhosis as the downstream consequence of hepatocyte cell death.
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "rapidly progressive nodular liver fibrosis, tubulopathy and severe clotting disturbances"
    explanation: Patient reports support progressive hepatic fibrosis and systemic consequences.
  downstream:
  - target: Cirrhosis
    description: Hepatocyte injury and fibrosis produce cirrhosis.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:17613166
      reference_title: "The pathogenesis of transaldolase deficiency."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "liver cirrhosis which results from increased cell death of hepatocytes"
      explanation: The pathogenesis review supports cirrhosis as a downstream liver outcome.
  - target: Hepatosplenomegaly
    description: Severe liver-centered transaldolase deficiency is associated with hepatosplenomegaly, but the cached evidence does not specify the intermediate mechanism.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Transaldolase deficiency is an inborn error of the pentose phosphate pathway that presents in the neonatal or antenatal period with hydrops fetalis, hepatosplenomegaly, hepatic dysfunction, thrombocytopenia, anemia, and renal and cardiac abnormalities."
      explanation: Orphanet definition links the disorder's hepatic presentation with hepatosplenomegaly.
  - target: Thrombocytopenia
    description: Severe liver-centered transaldolase deficiency is associated with thrombocytopenia, but the cached evidence does not specify the intermediate mechanism.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:24497183
      reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "hepatosplenomegaly, thrombocytopenia, anaemia, bleeding diathesis, liver failure"
      explanation: The clinical report lists thrombocytopenia with hepatosplenomegaly and liver failure.
  - target: Anemia
    description: Severe liver-centered transaldolase deficiency is associated with anemia, but the cached evidence does not specify the intermediate mechanism.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:24497183
      reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "hepatosplenomegaly, thrombocytopenia, anaemia, bleeding diathesis, liver failure"
      explanation: The clinical report lists anemia with hepatosplenomegaly and liver failure.
  - target: Telangiectasia
    description: Liver damage is associated with spider angiomas and visible skin vessels.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Liver damage with visible skin-vessel changes.
    evidence:
    - reference: PMID:24497183
      reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "These skin changes, characteristic of liver damage, immediately made us consider transaldolase deficiency"
      explanation: The report links visible skin vessel changes to liver damage in transaldolase deficiency.
  - target: Increased serum bile acid concentration
    description: Hepatic dysfunction in transaldolase deficiency is associated with increased serum bile acids.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: ORPHA:101028
      reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0012202 | Increased serum bile acid concentration | Very frequent (99-80%)"
      explanation: Orphanet records increased serum bile acid concentration as a very frequent phenotype.
biochemical:
- name: Reduced transaldolase activity
  presence: DECREASED
  context: >
    Patient-derived fibroblast and lymphoblast studies and recombinant protein
    assays show loss of transaldolase enzymatic activity in disease-associated
    TALDO1 variants.
  readouts:
  - target: TALDO1 transaldolase activity deficiency
    relationship: READOUT_OF
    direction: NEGATIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >
      Reduced transaldolase enzyme activity directly reports the primary TALDO1
      catalytic-function defect.
    evidence:
    - reference: PMID:15115436
      reference_title: "Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "no expression of the TALDeltaS171 protein or enzyme activity was detected"
      explanation: Patient-cell experiments show absent transaldolase protein/enzyme activity, supporting enzyme activity as a direct readout of the root mechanism.
  evidence:
  - reference: PMID:15115436
    reference_title: "Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "no expression of the TALDeltaS171 protein or enzyme activity was detected"
    explanation: Patient-cell experiments support reduced transaldolase activity as the primary biochemical defect.
- name: Increased urinary polyols and seven-carbon sugars
  presence: INCREASED
  context: >
    Urine testing shows increased erythritol, ribitol, arabitol, sedoheptitol,
    perseitol, sedoheptulose, and sedoheptulose-7-phosphate, supporting the
    biochemical diagnosis.
  readouts:
  - target: Pentose phosphate pathway metabolite imbalance
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >
      Increased urinary polyols and seven-carbon sugars report the downstream
      pentose-phosphate metabolite imbalance caused by transaldolase deficiency.
    evidence:
    - reference: PMID:24497183
      reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Elevated excretion of erythritol, ribitol, arabitol, sedoheptitol, perseitol, sedoheptulose and sedoheptulose-7P in the urine"
      explanation: Human urine testing directly supports the metabolite panel as a diagnostic readout of the pentose-phosphate metabolite imbalance.
  evidence:
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Elevated excretion of erythritol, ribitol, arabitol, sedoheptitol, perseitol, sedoheptulose and sedoheptulose-7P in the urine"
    explanation: The patient report provides the diagnostic urinary metabolite pattern.
  - reference: PMID:29923087
    reference_title: "Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Urine polyols and plasma metabolomics confirmed the diagnosis of transaldolase deficiency."
    explanation: Human metabolomics data support urine polyols as diagnostic biochemical evidence.
genetic:
- name: Biallelic TALDO1 pathogenic variants
  gene_term:
    preferred_term: TALDO1
    term:
      id: hgnc:11559
      label: TALDO1
  association: Causative
  relationship_type: CAUSATIVE
  features: >
    Transaldolase deficiency is caused by biallelic pathogenic variants in
    TALDO1. Reported mechanisms include missense variants and deletions that
    abolish enzyme activity or destabilize transaldolase protein.
  inheritance:
  - name: Autosomal recessive inheritance
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "TALDO1 | transaldolase 1 | hgnc:11559 | Disease-causing germline mutation(s) in"
    explanation: Orphanet records TALDO1 as disease-causing.
  - reference: PMID:23315216
    reference_title: "Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "sequencing confirmed segregation of a novel homozygous mutation with the disease"
    explanation: Segregation in affected families supports recessive TALDO1 causality.
  - reference: PMID:38440129
    reference_title: "Hypergonadotropic Hypogonadism Due to Transaldolase Deficiency: Two Cases and Literature Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "caused by pathogenic/likely pathogenic biallelic mutations in the TALDO1 gene"
    explanation: Recent clinical review supports biallelic TALDO1 variants as the molecular cause.
phenotypes:
- name: Cirrhosis
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Cirrhosis
    term:
      id: HP:0001394
      label: Cirrhosis
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001394 | Cirrhosis | Very frequent (99-80%)"
    explanation: Orphanet records cirrhosis as a very frequent phenotype.
  - reference: PMID:18331807
    reference_title: "Transaldolase deficiency in a two-year-old boy with cirrhosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "subsequently found to have cirrhosis and deafness"
    explanation: The clinical report documents cirrhosis in a child with TALDO deficiency.
- name: Hepatosplenomegaly
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Hepatosplenomegaly
    term:
      id: HP:0001433
      label: Hepatosplenomegaly
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001433 | Hepatosplenomegaly | Very frequent (99-80%)"
    explanation: Orphanet records hepatosplenomegaly as a very frequent phenotype.
  - reference: PMID:25388407
    reference_title: "Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The patients had variable clinical presentations including hepatosplenomegaly"
    explanation: Patient-level evidence supports hepatosplenomegaly.
- name: Thrombocytopenia
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Thrombocytopenia
    term:
      id: HP:0001873
      label: Thrombocytopenia
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001873 | Thrombocytopenia | Very frequent (99-80%)"
    explanation: Orphanet records thrombocytopenia as a very frequent phenotype.
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "hepatosplenomegaly, thrombocytopenia, anaemia, bleeding diathesis, liver failure"
    explanation: The clinical report supports thrombocytopenia in affected patients.
- name: Anemia
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Anemia
    term:
      id: HP:0001903
      label: Anemia
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001903 | Anemia | Very frequent (99-80%)"
    explanation: Orphanet records anemia as a very frequent phenotype.
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "hepatosplenomegaly, thrombocytopenia, anaemia, bleeding diathesis, liver failure"
    explanation: The clinical report supports anemia in affected patients.
- name: Abnormality of glutamine metabolism
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Abnormal circulating glutamine concentration
    term:
      id: HP:0010903
      label: Abnormal circulating glutamine concentration
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0010903 | Abnormality of glutamine metabolism | Very frequent (99-80%)"
    explanation: Orphanet records abnormal glutamine metabolism as very frequent.
- name: Increased serum bile acid concentration
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Increased serum bile acid concentration
    term:
      id: HP:0012202
      label: Increased serum bile acid concentration
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0012202 | Increased serum bile acid concentration | Very frequent (99-80%)"
    explanation: Orphanet records increased serum bile acids as very frequent.
- name: Abnormality of the clitoris
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Abnormality of the clitoris
    term:
      id: HP:0000056
      label: Abnormal clitoris morphology
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0000056 | Abnormality of the clitoris | Frequent (79-30%)"
    explanation: Orphanet records clitoral abnormality as frequent.
- name: Abnormality of the kidney
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Abnormality of the kidney
    term:
      id: HP:0000077
      label: Abnormality of the kidney
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0000077 | Abnormality of the kidney | Frequent (79-30%)"
    explanation: Orphanet records kidney abnormality as frequent.
  - reference: PMID:25388407
    reference_title: "Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "renal and cardiac abnormalities, and urinary excretion of polyols."
    explanation: Patient-series abstract supports renal abnormalities in the disorder.
- name: Edema
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Edema
    term:
      id: HP:0000969
      label: Edema
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0000969 | Edema | Frequent (79-30%)"
    explanation: Orphanet records edema as frequent.
- name: Telangiectasia
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Telangiectasia
    term:
      id: HP:0001009
      label: Telangiectasia
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001009 | Telangiectasia | Frequent (79-30%)"
    explanation: Orphanet records telangiectasia as frequent.
  - reference: PMID:25388407
    reference_title: "Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "skin manifestations (e.g., dryness, cutis laxa, ichthyosis, telangiectasias, and hemangiomas)."
    explanation: Patient-series abstract supports telangiectasias.
- name: Hydrops fetalis
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Hydrops fetalis
    term:
      id: HP:0001789
      label: Hydrops fetalis
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001789 | Hydrops fetalis | Frequent (79-30%)"
    explanation: Orphanet records hydrops fetalis as frequent.
  - reference: PMID:25388407
    reference_title: "Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "proteinuria, hydrops fetalis, cardiomyopathy, and skin manifestations"
    explanation: Patient-series abstract supports hydrops fetalis.
- name: Abnormal facial shape
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Abnormal facial shape
    term:
      id: HP:0001999
      label: Abnormal facial shape
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001999 | Abnormal facial shape | Frequent (79-30%)"
    explanation: Orphanet records abnormal facial shape as frequent.
  - reference: PMID:23315216
    reference_title: "Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "growth retardation, dysmorphic features, cutis laxa, congenital heart disease"
    explanation: The 12-case series supports dysmorphic features.
- name: Premature skin wrinkling
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Premature skin wrinkling
    term:
      id: HP:0100678
      label: Premature skin wrinkling
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0100678 | Premature skin wrinkling | Frequent (79-30%)"
    explanation: Orphanet records premature skin wrinkling as frequent.
  - reference: PMID:23315216
    reference_title: "Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "growth retardation, dysmorphic features, cutis laxa, congenital heart disease"
    explanation: The 12-case series supports cutis laxa and abnormal skin findings.
- name: Global developmental delay
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Global developmental delay
    term:
      id: HP:0001263
      label: Global developmental delay
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001263 | Global developmental delay | Occasional (29-5%)"
    explanation: Orphanet records global developmental delay as occasional.
- name: Atrial septal defect
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Atrial septal defect
    term:
      id: HP:0001631
      label: Atrial septal defect
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001631 | Atrial septal defect | Occasional (29-5%)"
    explanation: Orphanet records atrial septal defect as occasional.
- name: Coarctation of aorta
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Coarctation of aorta
    term:
      id: HP:0001680
      label: Coarctation of aorta
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001680 | Coarctation of aorta | Occasional (29-5%)"
    explanation: Orphanet records coarctation of aorta as occasional.
- name: Abnormal respiratory system physiology
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Abnormal respiratory system physiology
    term:
      id: HP:0002795
      label: Abnormal respiratory system physiology
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0002795 | Abnormal respiratory system physiology | Occasional (29-5%)"
    explanation: Orphanet records respiratory physiology abnormality as occasional.
- name: Biventricular hypertrophy
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Biventricular hypertrophy
    term:
      id: HP:0200128
      label: Biventricular hypertrophy
  evidence:
  - reference: ORPHA:101028
    reference_title: "Transaldolase deficiency (Orphanet structured-database record)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0200128 | Biventricular hypertrophy | Occasional (29-5%)"
    explanation: Orphanet records biventricular hypertrophy as occasional.
- name: Hypergonadotropic hypogonadism
  frequency: OCCASIONAL
  phenotype_term:
    preferred_term: Hypergonadotropic hypogonadism
    term:
      id: HP:0000815
      label: Hypergonadotropic hypogonadism
  evidence:
  - reference: PMID:38440129
    reference_title: "Hypergonadotropic Hypogonadism Due to Transaldolase Deficiency: Two Cases and Literature Review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "two Emirati patients with hypergonadotropic hypogonadism due to transaldolase deficiency"
    explanation: The case report directly documents hypergonadotropic hypogonadism in transaldolase deficiency.
  - reference: PMID:33159679
    reference_title: "Hypergonadotrophic hypogonadism in a patient with transaldolase deficiency: novel mutation in the pentose phosphate pathway."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "deficiency characterized by hypergonadotropic hypogonadism and slightly elevated"
    explanation: A late-onset patient report supports hypergonadotropic hypogonadism as a variable manifestation.
diagnosis:
- name: Urinary polyol and seven-carbon sugar testing
  description: >
    Gas chromatography and liquid chromatography-tandem mass spectrometry of
    urine can identify increased polyols and seven-carbon sugars, including
    sedoheptulose and sedoheptulose-7-phosphate, supporting the biochemical
    diagnosis.
  results: Increased urinary polyols and seven-carbon sugars support transaldolase deficiency.
  evidence:
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The diagnosis was established by detecting high concentrations of erythritol, ribitol, arabitol"
    explanation: The report supports urinary sugar/polyol profiling as a diagnostic approach.
- name: TALDO1 molecular genetic testing
  description: >
    Molecular testing confirms biallelic TALDO1 pathogenic variants, including
    sequence variants and exon-level deletions that may require copy-number or
    long-range PCR approaches when sequencing finds only one allele.
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: MAXO:0000533
      label: molecular genetic testing
  evidence:
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "then confirmed by molecular analysis of the TALDO gene."
    explanation: The clinical report supports molecular confirmation of biochemical diagnosis.
treatments:
- name: Supportive management and acetaminophen avoidance
  description: >
    Disease-specific management is supportive and should include avoidance of
    acetaminophen because clinical and model evidence indicates increased
    vulnerability to acetaminophen-related oxidative liver injury.
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
  target_mechanisms:
  - target: Redox and mitochondrial stress signaling
    treatment_effect: MODULATES
    description: Acetaminophen avoidance reduces exposure to a trigger that can accentuate oxidative liver stress in transaldolase deficiency.
    evidence:
    - reference: PMID:29923087
      reference_title: "Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "transaldolase-deficient patients are uniquely sensitive to acetaminophen and should avoid this antipyretic."
      explanation: The human case report supports avoidance of acetaminophen as a way to reduce oxidative liver-injury risk.
  evidence:
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Symptomatic treatment can be proposed."
    explanation: The clinical report states that symptomatic treatment can be proposed.
  - reference: PMID:29923087
    reference_title: "Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "transaldolase-deficient patients are uniquely sensitive to acetaminophen and should avoid this antipyretic."
    explanation: A human case and supporting model evidence support acetaminophen avoidance.
- name: N-acetylcysteine for oxidative liver stress
  description: >
    N-acetylcysteine has model-organism support for preventing acetaminophen-
    induced liver failure and limited human observational support for lowering
    alpha-fetoprotein, so it is recorded as a context-specific antioxidant
    option rather than established disease-modifying therapy.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: N-acetyl-L-cysteine
      term:
        id: CHEBI:28939
        label: N-acetyl-L-cysteine
  target_mechanisms:
  - target: Redox and mitochondrial stress signaling
    treatment_effect: MODULATES
    description: N-acetylcysteine is an antioxidant intended to reduce oxidative liver stress.
    evidence:
    - reference: PMID:29923087
      reference_title: "Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "acetaminophen-induced liver failure can be prevented by administration of the antioxidant N-acetylcysteine."
      explanation: Mouse-model evidence supports an antioxidant rescue mechanism.
  evidence:
  - reference: PMID:29923087
    reference_title: "Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "treatment of a transaldolase-deficient patient with N-acetylcysteine was associated with a decrease"
    explanation: Published human experience provides limited supportive evidence for NAC use.
- name: Liver transplantation consideration
  description: >
    Early liver transplantation has been proposed for severe progressive liver
    disease, but the available cached evidence is cautious and not sufficient
    to establish benefit.
  treatment_term:
    preferred_term: organ transplantation
    term:
      id: MAXO:0010039
      label: organ transplantation
  target_mechanisms:
  - target: Hepatic fibrosis and cirrhosis
    treatment_effect: MODULATES
    description: Liver transplantation has been proposed as a possible intervention for early severe liver disease, but the evidence remains tentative.
    evidence:
    - reference: PMID:24497183
      reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
      supports: PARTIAL
      evidence_source: HUMAN_CLINICAL
      snippet: "Liver transplantation in the early stage of the disease could perhaps be useful."
      explanation: The report proposes transplantation for severe liver disease but does not establish efficacy.
  evidence:
  - reference: PMID:24497183
    reference_title: "Clinical and molecular characteristics of two transaldolase-deficient patients."
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "Liver transplantation in the early stage of the disease could perhaps be useful."
    explanation: The report proposes liver transplantation as a possible option but does not prove efficacy.
references:
- reference: ORPHA:101028
  title: Transaldolase deficiency
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Orphanet provides definition, inheritance, prevalence, onset, TALDO1 association, exact MONDO/OMIM mappings, and HPO phenotype frequencies.
    supporting_text: ORPHA:101028 structured record.
- reference: PMID:23315216
  title: "Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype."
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Twelve new cases expand the clinical phenotype and support TALDO segregation.
    supporting_text: Cohort abstract reporting growth retardation, dysmorphism, cutis laxa, congenital heart disease, hepatosplenomegaly, pancytopenia, bleeding tendency, and TALDO segregation.
- reference: PMID:25388407
  title: "Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability."
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Four-patient series supports broad phenotypic variability, urinary polyols, and biallelic TALDO1 causality.
    supporting_text: Abstract lists dysmorphic, skin, liver, renal, cardiac, hematologic, hydrops, and urinary polyol findings.
- reference: PMID:24497183
  title: Clinical and molecular characteristics of two transaldolase-deficient patients.
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Full-text clinical report supports neonatal presentation, urinary sugar/polyol diagnostics, liver fibrosis, tubulopathy, and symptomatic management.
    supporting_text: Full-text cache includes biochemical diagnosis and clinical course of two patients.
- reference: PMID:15115436
  title: "Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase."
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Patient-cell and recombinant protein experiments support loss of transaldolase activity through proteasome-mediated degradation.
    supporting_text: Abstract reports no mutant protein/enzyme activity and proteasome-dependent accumulation.
- reference: PMID:17613166
  title: The pathogenesis of transaldolase deficiency.
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Review links pentose-phosphate NADPH/ROI balance with mitochondrial membrane potential, cell survival, and hepatocyte cell death.
    supporting_text: Abstract describes NADPH, reactive oxygen intermediates, mitochondrial membrane potential, and hepatocyte cell death.
- reference: PMID:29923087
  title: Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency.
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Case report and mouse-model evidence support acetaminophen sensitivity, acetaminophen avoidance, and limited NAC evidence.
    supporting_text: Abstract reports acetaminophen-associated liver failure, model rescue by N-acetylcysteine, and avoidance recommendation.
- reference: PMID:33159679
  title: "Hypergonadotrophic hypogonadism in a patient with transaldolase deficiency: novel mutation in the pentose phosphate pathway."
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Later-onset case supports expanded endocrine phenotype and variable presentation.
    supporting_text: Abstract reports hypergonadotropic hypogonadism and elevated AFP with novel TALDO1 mutation.
- reference: PMID:38440129
  title: "Hypergonadotropic Hypogonadism Due to Transaldolase Deficiency: Two Cases and Literature Review."
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Recent case report and review support autosomal recessive TALDO1 causality and multisystem phenotype.
    supporting_text: Abstract describes biallelic TALDO1 mutations and variable multisystem involvement.
- reference: PMID:18331807
  title: Transaldolase deficiency in a two-year-old boy with cirrhosis.
  found_in:
  - Transaldolase_Deficiency-deep-research-openai.md
  findings:
  - statement: Case report supports neonatal anemia/thrombocytopenia, renal tubulopathy, cirrhosis, and deafness.
    supporting_text: Abstract describes clinical presentation and laboratory findings in a two-year-old boy.
differential_diagnoses: []
📚

References & Deep Research

References

10
ORPHA:101028
Transaldolase deficiency
1 finding
Orphanet provides definition, inheritance, prevalence, onset, TALDO1 association, exact MONDO/OMIM mappings, and HPO phenotype frequencies.
"ORPHA:101028 structured record."
PMID:23315216
Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype.
1 finding
Twelve new cases expand the clinical phenotype and support TALDO segregation.
"Cohort abstract reporting growth retardation, dysmorphism, cutis laxa, congenital heart disease, hepatosplenomegaly, pancytopenia, bleeding tendency, and TALDO segregation."
PMID:25388407
Transaldolase deficiency caused by the homozygous p.R192C mutation of the TALDO1 gene in four Emirati patients with considerable phenotypic variability.
1 finding
Four-patient series supports broad phenotypic variability, urinary polyols, and biallelic TALDO1 causality.
"Abstract lists dysmorphic, skin, liver, renal, cardiac, hematologic, hydrops, and urinary polyol findings."
PMID:24497183
Clinical and molecular characteristics of two transaldolase-deficient patients.
1 finding
Full-text clinical report supports neonatal presentation, urinary sugar/polyol diagnostics, liver fibrosis, tubulopathy, and symptomatic management.
"Full-text cache includes biochemical diagnosis and clinical course of two patients."
PMID:15115436
Deletion of Ser-171 causes inactivation, proteasome-mediated degradation and complete deficiency of human transaldolase.
1 finding
Patient-cell and recombinant protein experiments support loss of transaldolase activity through proteasome-mediated degradation.
"Abstract reports no mutant protein/enzyme activity and proteasome-dependent accumulation."
PMID:17613166
The pathogenesis of transaldolase deficiency.
1 finding
Review links pentose-phosphate NADPH/ROI balance with mitochondrial membrane potential, cell survival, and hepatocyte cell death.
"Abstract describes NADPH, reactive oxygen intermediates, mitochondrial membrane potential, and hepatocyte cell death."
PMID:29923087
Apparent Acetaminophen Toxicity in a Patient with Transaldolase Deficiency.
1 finding
Case report and mouse-model evidence support acetaminophen sensitivity, acetaminophen avoidance, and limited NAC evidence.
"Abstract reports acetaminophen-associated liver failure, model rescue by N-acetylcysteine, and avoidance recommendation."
PMID:33159679
Hypergonadotrophic hypogonadism in a patient with transaldolase deficiency: novel mutation in the pentose phosphate pathway.
1 finding
Later-onset case supports expanded endocrine phenotype and variable presentation.
"Abstract reports hypergonadotropic hypogonadism and elevated AFP with novel TALDO1 mutation."
PMID:38440129
Hypergonadotropic Hypogonadism Due to Transaldolase Deficiency: Two Cases and Literature Review.
1 finding
Recent case report and review support autosomal recessive TALDO1 causality and multisystem phenotype.
"Abstract describes biallelic TALDO1 mutations and variable multisystem involvement."
PMID:18331807
Transaldolase deficiency in a two-year-old boy with cirrhosis.
1 finding
Case report supports neonatal anemia/thrombocytopenia, renal tubulopathy, cirrhosis, and deafness.
"Abstract describes clinical presentation and laboratory findings in a two-year-old boy."

Deep Research

2
Transaldolase Deficiency Deep Research Fallback ▸

Transaldolase Deficiency Deep Research Fallback

Date: 2026-05-05T07:40:18Z

Provider Attempts

  • Falcon deep-research client was invoked directly with the disease pathophysiology template for Transaldolase deficiency (MONDO:0011624) and timed out after the bounded timeout interval with no usable report.
  • Earlier just research-disorder falcon Transaldolase_Deficiency could not run before the YAML file existed.

Evidence Scope Used for Curation

Because the provider attempt did not return a usable artifact, curation proceeded from structured Orphanet ORPHA:101028 and cached literature references. The main evidence set used was:

  • ORPHA:101028 for disease definition, inheritance, prevalence, TALDO1 gene association, MONDO/OMIM cross-references, and HPO phenotype frequency rows.
  • PMID:23315216 for a 12-patient clinical series defining the multisystem phenotype and TALDO segregation.
  • PMID:25388407 and PMID:24497183 for patient-level clinical variability, urinary polyol diagnostics, renal/cardiac/liver/skin features, and TALDO1 molecular confirmation.
  • PMID:15115436 for the Ser171 deletion mechanism causing transaldolase inactivation and proteasome-mediated degradation in patient-derived cells.
  • PMID:17613166 for pentose phosphate pathway redox biology and the hepatocyte cell-death/cirrhosis pathogenesis model.
  • PMID:29923087 for acetaminophen sensitivity, diagnostic metabolomics, and N-acetylcysteine/acetaminophen-avoidance management implications.
  • PMID:33159679 and PMID:38440129 for later endocrine presentations and the expanded multisystem clinical spectrum.

No uncached claims from the failed provider attempt were used.

OpenAI ▸
1. Disease Information
gpt-4o 2026-05-05T01:31:23.753458

1. Disease Information

Overview

Transaldolase deficiency is a rare autosomal recessive metabolic disorder characterized by impaired function of the transaldolase enzyme. This enzyme plays a critical role in the pentose phosphate pathway, influencing cellular redox balance and nucleotide synthesis.

Key Identifiers

  • OMIM: 606003
  • Orphanet: 1930
  • ICD-10: E88.8 (Other specified metabolic disorders)
  • MeSH: D055443
  • Mondo ID: MONDO:0010173

Synonyms

  • TALDO Deficiency
  • Taldo Deficiency

Data Source

The information derives from aggregated disease-level resources, primarily based on case reports and small patient cohorts due to its rarity.

2. Etiology

Disease Causal Factors

Genetic: Caused by mutations in the TALDO1 gene, which disrupt the function of the transaldolase enzyme (PMID: 15489859).

Risk Factors

Genetic: Mutations like c.708G>A, c.272_273del (PMID: 15489859).

Protective Factors

There are no well-documented genetic or environmental protective factors due to the rarity of the condition.

Gene-Environment Interactions

No significant gene-environment interactions have been documented.

3. Phenotypes

Phenotype Type

  • Symptoms: Hepatomegaly, liver failure, metabolic acidosis, and congenital heart defects (PMID: 15489859).

Phenotype Characteristics

  • Age of Onset: Early infancy
  • Symptom Severity: Severe; can be life-threatening
  • Progression: Progressive liver and multiorgan failure
  • Frequency: Present in all documented cases but based on a small sample size

Quality of Life Impact

Significant impact due to severe hepatomegaly and progressive liver failure. Affected individuals require comprehensive medical care.

Suggested HPO Terms

  • Hepatomegaly (HP:0002240)
  • Liver failure (HP:0001395)

4. Genetic/Molecular Information

Causal Genes

  • Gene: TALDO1
  • OMIM ID: 602061

Pathogenic Variants

  • Variant Type: Missense, nonsense
  • Allele Frequency: Rare in general population databases
  • Somatic vs. Germline Origin: Germline mutations

Functional Consequences

Loss of function leading to disruption of metabolic flux in the pentose phosphate pathway.

5. Environmental Information

Environmental Factors

No specific environmental factors have been implicated due to the genetic nature of the disorder.

Lifestyle Factors

No documented influence of lifestyle on the disorder's presentation or severity.

6. Mechanism / Pathophysiology

Molecular Pathways

Involves the pentose phosphate pathway; impairment leads to reduced antioxidant capacity and accumulation of toxic sugar metabolites (PMID: 15489859).

Protein Dysfunction

Enzyme deficiency results in abnormal cellular redox states and impaired nucleotide synthesis, leading to cell damage.

Metabolic Changes

Increased glutaric acid levels, reduced ribose-5-phosphate, and erythrose-4-phosphate.

7. Anatomical Structures Affected

Organ Level

  • Primary: Liver
  • Secondary: Heart

Tissue and Cell Level

  • Tissue Type: Hepatic tissue
  • Cell Populations: Hepatocytes

Subcellular Level

  • Cellular Compartments: Cytoplasm, where the enzyme primarily functions.

Localization

  • Anatomical Sites: Liver, potential involvement of cardiac tissue (UBERON:0002107).

8. Temporal Development

Onset

  • Age of Onset: Congenital to early infancy
  • Onset Pattern: Chronic, insidious

Progression

  • Rate: Rapid if untreated, with progressive liver failure

Patterns

Consistent progressive degeneration without remission

9. Inheritance and Population

Epidemiology

  • Prevalence: Extremely rare; exact prevalence not well-documented.
  • Inheritance Pattern: Autosomal recessive

Population Demographics

  • No specific ethnic or demographic predilection identified.

10. Diagnostics

Clinical Tests

  • Laboratory Tests: Measurement of pentose phosphate pathway metabolites
  • Genetic Testing: Mutation analysis of TALDO1 via sequencing or specific gene panels

Genetic Testing

  • Whole Exome Sequencing (WES): Preferred for diagnosing unknown metabolic disorders

Clinical Criteria

Diagnosis based on clinical presentation, biochemical testing, and genetic confirmation.

11. Outcome/Prognosis

Survival and Mortality

  • Mortality Rate: High without treatment due to liver failure

Morbidity and Function

Significant disability due to liver dysfunction.

12. Treatment

Pharmacotherapy

  • Supportive Care: Managing liver symptoms, addressing metabolic crises
  • Liver Transplant: Considered in severe cases for liver failure (MAXO:0001198).

13. Prevention

Genetic Counseling

  • Essential for families with known mutations, especially for planning future pregnancies.

14. Other Species / Natural Disease

No comparative animal models identified; condition largely unique to humans.

15. Model Organisms

No specific model organisms are used due to the rare nature of the disease and availability of clinical data.

This report integrates current knowledge on Transaldolase Deficiency relevant to clinical, genetic, and biochemical domains. Further research is critical to expand therapeutic and diagnostic developments. For comprehensive primary sources, please access linked PubMed articles using provided PMIDs.