Pyruvate Carboxylase Deficiency Disease (PCD) — Comprehensive Research Report

Executive summary

Pyruvate carboxylase deficiency (PCD) is an ultra-rare, autosomal recessive mitochondrial neurometabolic disorder caused by biallelic pathogenic variants in PC (pyruvate carboxylase; EC 6.4.1.1) that impair conversion of pyruvate to oxaloacetate, disrupting anaplerosis and gluconeogenesis and leading to lactic acidosis, hypoglycemia, neurodevelopmental impairment, and characteristic neuroimaging abnormalities (lasio2023clinicalbiochemicaland pages 1-3, marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2). Contemporary (2023–2024) case reports and the largest available treatment cohort (n=12) underscore (i) severe neonatal mortality in type B disease, (ii) genotype- and phenotype-dependent variability, and (iii) mixed outcomes for anaplerotic therapy with triheptanoin, with a notable apparent benefit in a type C patient (xue2023casereportprenatal pages 1-2, jasinge2024clinicalbiochemicaland pages 2-4, lasio2023clinicalbiochemicaland pages 9-11, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Key identifiers and nomenclature (disease information)

What is the disease? A disorder of intermediary metabolism in which deficiency of the mitochondrial biotin-dependent enzyme pyruvate carboxylase limits formation of oxaloacetate from pyruvate, causing multiorgan metabolic imbalance dominated by lactic acidemia/acidosis and early neurologic dysfunction (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2, mochel2005pyruvatecarboxylasedeficiency pages 1-2).

Identifiers available in retrieved evidence - OMIM: 266150 (PCD) (xue2023casereportprenatal pages 1-2, lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2) - MONDO: - MONDO_0018141 (infantile form) - MONDO_0018142 (severe neonatal type) - MONDO_0018143 (benign type) (from OpenTargets disease-target associations evidence) (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2) - MeSH term present in ClinicalTrials.gov record: “Pyruvate Carboxylase Deficiency Disease” (NCT01461304 chunk 1)

Not found in accessible full-text evidence for this run: Orphanet/ORPHAcode, ICD-10/ICD-11, and a curated MONDO ID for the umbrella disease beyond subtype MONDO terms.

Common synonyms / alternative names (from literature usage) - “Pyruvate carboxylase (PC) deficiency” (lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2) - “PCD type A / infantile / North American form” (xue2023casereportprenatal pages 1-2, lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2) - “PCD type B / severe neonatal / French form” (xue2023casereportprenatal pages 1-2, mochel2005pyruvatecarboxylasedeficiency pages 1-2, wang2008themolecularbasis pages 1-2) - “PCD type C / intermittent / benign form” (xue2023casereportprenatal pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2, wang2008themolecularbasis pages 1-2)

Evidence provenance: For this rare disease, much of the clinical description derives from individual cases and small series rather than large registries; a notable aggregated cohort is the 12-patient triheptanoin-treated series (lasio2023clinicalbiochemicaland pages 1-3, lasio2023clinicalbiochemicaland pages 9-11).

Artifact: identifiers and subtype snapshot

Table: This table summarizes core disease identifiers, inheritance, subtype-defining features, epidemiology, and recent 2023–2024 primary literature for pyruvate carboxylase deficiency. It is designed as a compact reference for rapid evidence-grounded review.

Etiology

Disease causal factors

Genetic cause: Biallelic pathogenic variants in PC cause PCD (autosomal recessive) (lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Molecular function: PC catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate (OAA), supporting gluconeogenesis and replenishing tricarboxylic acid (TCA) cycle intermediates (anaplerosis) (mochel2005pyruvatecarboxylasedeficiency pages 1-2, marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).

Risk factors

• Family history / autosomal recessive inheritance (lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2)
• Consanguinity is highlighted in recent neonatal series from Sri Lanka (two consanguineous families) (jasinge2024clinicalbiochemicaland pages 2-4).

Protective factors

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

Gene–environment interactions

No direct gene–environment interaction studies were retrieved; however, metabolic stress/infections can precipitate decompensation episodes in infantile forms (wang2008themolecularbasis pages 1-2).

Phenotypes (clinical spectrum)

PCD is classically divided into three overlapping phenotypes (A/B/C) (xue2023casereportprenatal pages 1-2, wang2008themolecularbasis pages 1-2, marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).

Type B (severe neonatal) — high mortality

• Onset: within hours to first 72 hours of life (xue2023casereportprenatal pages 1-2, jasinge2024clinicalbiochemicaland pages 2-4).
• Key manifestations: severe lactic acidosis with metabolic acidosis, hyperammonemia and hypercitrullinemia, hypotonia, seizures, abnormal movements, and frequent early death (xue2023casereportprenatal pages 1-2, wang2008themolecularbasis pages 1-2, jasinge2024clinicalbiochemicaland pages 2-4).
• Quantitative examples:
• In the Chinese type B case: arterial pH 7.24, HCO3− 5.2 mM, urine lactic acid 7262 nmol/mg creatinine, urine pyruvate 1416.8 nmol/mg creatinine, urine 3-hydroxybutyrate 1725.3 nmol/mg creatinine (xue2023casereportprenatal pages 1-2).
• In the Sri Lankan neonatal series: example lactate 18.75 mmol/L, pH 7.12, HCO3− 4.2 mmol/L, glucose 38 mg/dL (jasinge2024clinicalbiochemicaland pages 2-4).

Type A (infantile)

• Onset: infancy; neonatal overlap reported (lasio2023clinicalbiochemicaland pages 1-3, jasinge2024clinicalbiochemicaland pages 1-2).
• Key manifestations: lactic acidosis/hyperlactataemia, ketosis, hypotonia, seizures, developmental delay; death often in infancy/early childhood (lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2).

Type C (intermittent/benign/attenuated)

• Onset/course: episodic metabolic decompensation; comparatively favorable prognosis (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).
• Clinical pattern: episodic hyperlactataemia and ketoacidosis with milder developmental delay and variable myelination changes (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).
• Quantitative example: persistent lactate 4.1–5.9 mmol/L with lactate:pyruvate ratio 24–29 (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Suggested HPO terms (non-exhaustive; based on phenotypes repeatedly described)

• Metabolic/biochemical: Lactic acidosis (HP:0003128), Metabolic acidosis (HP:0001942), Hypoglycemia (HP:0001943), Hyperammonemia (HP:0001987), Ketonuria (HP:0002919), Ketoacidosis (HP:0001993)
• Neurologic: Hypotonia (HP:0001252), Seizures (HP:0001250), Developmental delay (HP:0001263), Encephalopathy (HP:0001298), Abnormal movement (HP:0001270)
• Respiratory: Tachypnea/Respiratory distress (HP:0002094/HP:0002098)
• Neuroimaging: Delayed myelination (HP:0003429), Ventriculomegaly (HP:0002119), Subependymal cysts (HP:0010629) (supported by case descriptions) (xue2023casereportprenatal pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Genetic / molecular information

Causal gene

• PC (pyruvate carboxylase), nuclear-encoded mitochondrial enzyme; gene maps to 11q13 region and encodes a ~125 kDa protein; multiple transcripts exist (wang2008themolecularbasis pages 1-2).

Pathogenic variant spectrum (classes and recent examples)

Variant classes include missense, nonsense/frameshift, small deletions/insertions, splice-site variants, and (importantly for diagnostics) deep intronic and structural variants (reciprocal translocation disrupting PC) (tsygankova2022expandingthegenetic pages 1-2, wang2008themolecularbasis pages 1-2).

Recent (2023–2024) examples - Type B: compound heterozygous variants c.1154_1155del and c.152G>A (China case report) (xue2023casereportprenatal pages 1-2). - Type B: homozygous frameshift c.908delG:p.G303Afs40 (likely pathogenic) and homozygous missense p.R156P (VUS in paper but argued damaging by in silico modeling) (maryami2023insilicoanalysis pages 1-2, maryami2023insilicoanalysis pages 2-4). - Sri Lankan neonates: homozygous nonsense c.2514G>A (p.Trp838) in one proband; novel homozygous missense c.2746G>C (p.Asp916His) in another (jasinge2024clinicalbiochemicaland pages 2-4, jasinge2024clinicalbiochemicaland pages 1-2).

Deep intronic / structural findings (diagnostic expansion) - Homozygous deep intronic c.1983-116C>T caused exonization (residual WT transcript present) (tsygankova2022expandingthegenetic pages 1-2). - Reciprocal translocation disrupting PC discovered by WGS and validated by FISH/Sanger (tsygankova2022expandingthegenetic pages 1-2).

Variant counts (HGMD snapshot as of 2022-06-12) A 2022 report states 62 PC variants in HGMD, with distribution: 42 missense/nonsense, 7 splicing, 7 small deletions, 5 small insertions, 1 small duplication; and noted that large structural or deep intronic variants had not been reported at that time—their paper then contributed such variant classes (tsygankova2022expandingthegenetic pages 1-2).

Modifier-like genetic factors

Somatic mosaicism: In an 8-patient molecular series (1 type A, 5 type B, 2 type C), mosaicism was found in 5 cases and 4 had prolonged survival; authors concluded survival correlated better with mosaicism than with classical phenotype labels or residual protein (wang2008themolecularbasis pages 1-2).

Environmental information

No specific environmental toxins, lifestyle factors, or infectious agents as causal contributors were identified. Intercurrent infections/illnesses are repeatedly described as triggers for metabolic decompensation (e.g., type C and type A/B overlap cases) (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2, wang2008themolecularbasis pages 1-2).

Mechanism / pathophysiology

Core biochemical lesion and causal chain

1. PC loss-of-function reduces conversion of pyruvate → oxaloacetate (OAA) in mitochondria (mochel2005pyruvatecarboxylasedeficiency pages 1-2, marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).
2. OAA deficit impairs replenishment of TCA intermediates (anaplerosis) and compromises gluconeogenesis (mochel2005pyruvatecarboxylasedeficiency pages 1-2, marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).
3. Energy failure and redox imbalance promote lactic acidosis (often severe in type B) and can lead to hypoglycemia (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2, jasinge2024clinicalbiochemicaland pages 2-4).
4. Disruption of aspartate/OAA-dependent processes contributes to urea-cycle perturbation, manifesting as hypercitrullinemia and hyperammonemia in severe neonatal disease (wang2008themolecularbasis pages 1-2, xue2023casereportprenatal pages 1-2).
5. CNS vulnerability: PC activity is robust in glia but absent in neurons; glial anaplerosis supports glutamine supply for neuronal glutamate/GABA, providing a mechanistic basis for neurologic dysfunction and encephalopathy (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).

Pathways and ontology suggestions

• Pathways: TCA cycle / Krebs cycle; gluconeogenesis; anaplerotic reactions (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2, mochel2005pyruvatecarboxylasedeficiency pages 1-2).
• GO biological process (suggested): anaplerotic reaction; gluconeogenesis; tricarboxylic acid cycle; regulation of cellular redox homeostasis.
• GO molecular function (suggested): pyruvate carboxylase activity.
• Cell types (CL suggested): astrocyte (glial PC activity emphasized) (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).
• Anatomy (UBERON suggested): liver, brain, kidney, pancreatic islet (high PC activity tissues) (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2, wang2008themolecularbasis pages 1-2).
• CHEBI suggested: pyruvate, oxaloacetate, lactate, alanine, citrate, aspartate, ammonia.

Anatomical structures affected

• Primary systems/organs: CNS/brain (encephalopathy, seizures, myelination abnormalities), liver (hepatic failure in severe neonatal cases), metabolic homeostasis broadly (mochel2005pyruvatecarboxylasedeficiency pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2, jasinge2024clinicalbiochemicaland pages 2-4).
• Neuroimaging localizations: delayed cerebral myelination and cystic white matter/ventricular abnormalities have been documented, including prenatal onset as early as 22w5d gestation (xue2023casereportprenatal pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).
• Subcellular (GO cellular component suggested): mitochondrial matrix (PC localization) (tsygankova2022expandingthegenetic pages 1-2).

Temporal development

• Type B: acute neonatal presentation; often death within weeks to months. A specific case died at 26 days (xue2023casereportprenatal pages 1-2). A 2024 series notes two neonates died within the first six weeks (jasinge2024clinicalbiochemicaland pages 2-4).
• Type A: onset in infancy with variable course; death often in infancy/early childhood (lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2).
• Type C: episodic course with comparatively favorable prognosis and longer survival; symptomatic crises can be triggered by illness/exertion (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Inheritance and population

• Inheritance: autosomal recessive (lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2).
• Epidemiology: multiple sources cite an estimate of ~1 in 250,000 live births/births (lasio2023clinicalbiochemicaland pages 1-3, xue2023casereportprenatal pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2, marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2, tsygankova2022expandingthegenetic pages 1-2).
• Population clusters: 2010 review notes higher reporting in specific groups (Algonquian-speaking Amerindians and Arabs) (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).

Diagnostics

Biochemical testing (core real-world implementation)

• Blood gases / lactate: PCD often presents with lactic acidemia; mechanistic review gives typical lactic acid >5 mmol/L and bicarbonate <18 mmol/L (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2). Severe type B often has lactate >10 mmol/L (jasinge2024clinicalbiochemicaland pages 1-2, mochel2005pyruvatecarboxylasedeficiency pages 1-2).
• Redox ratios: elevated lactate:pyruvate and altered ketone ratios (acetoacetate:β-hydroxybutyrate; 3-hydroxybutyrate:acetoacetate) described as characteristic, especially in type B (lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2).
• Plasma amino acids: elevations can include alanine, citrulline, proline, lysine (especially type B) (lasio2023clinicalbiochemicaland pages 1-3, wang2008themolecularbasis pages 1-2, jasinge2024clinicalbiochemicaland pages 2-4).
• Urine organic acids: elevated lactate and ketone bodies; some reports describe reduced excretion of TCA intermediates (jasinge2024clinicalbiochemicaland pages 2-4, mochel2005pyruvatecarboxylasedeficiency pages 1-2).

Imaging

• Brain MRI features include delayed myelination/hypomyelination and cystic/ventricular abnormalities; prenatal imaging abnormalities can occur (xue2023casereportprenatal pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Enzyme assays

• Definitive diagnosis may require enzymatic assay; a 2010 review states enzymatic assay is “still often required” (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).
• Enzyme activity can be assessed in cultured fibroblasts (also referenced as a definitive approach in 2022 genetic paper) (tsygankova2022expandingthegenetic pages 1-2, habarou2015pyruvatecarboxylasedeficiency pages 2-3).
• Prenatal confirmation can include PC activity measurement in chorionic villi or cultured amniotic fluid cells (xue2023casereportprenatal pages 5-7).

Genetic testing approach

• WES used in multiple recent cases (China type B report; Maryami 2023; Tsygankova 2022) (xue2023casereportprenatal pages 1-2, maryami2023insilicoanalysis pages 2-4, tsygankova2022expandingthegenetic pages 1-2).
• WGS with deep analysis is recommended when standard testing yields 0–1 pathogenic allele, as deep intronic and structural variants can be missed (tsygankova2022expandingthegenetic pages 1-2).

Differential diagnosis

Several disorders can overlap with lactic acidosis and neurologic dysfunction (e.g., other disorders of pyruvate metabolism/TCA cycle, mitochondrial respiratory chain disorders); misdiagnosis as respiratory chain defect has been documented (habarou2015pyruvatecarboxylasedeficiency pages 1-2).

Screening

No evidence in the retrieved corpus supports routine newborn screening for PCD.

Outcome / prognosis

• Mechanistic review: “There is no effective treatment… most, except those affected by the benign form, die in early life” (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2).
• Type B neonatal cases frequently die early despite supportive care (e.g., death at 26 days) (xue2023casereportprenatal pages 1-2).
• Prognostic modifier: somatic mosaicism correlates with prolonged survival (wang2008themolecularbasis pages 1-2).

Treatment

Acute management (real-world implementation)

• Anti-catabolic therapy (e.g., dextrose-containing IV fluids) and correction of acidosis (bicarbonate) are repeatedly used in severe neonatal presentations and reviews (lasio2023clinicalbiochemicaland pages 3-4, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2, xue2023casereportprenatal pages 1-2, jasinge2024clinicalbiochemicaland pages 2-4).

Cofactors / supplements (supportive)

• Biotin is frequently trialed (minimal effect in A/B; occasional benefit reported in C) (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).
• Thiamine, riboflavin, carnitine, CoQ10 and other supportive measures are commonly administered in case management (xue2023casereportprenatal pages 1-2, mochel2005pyruvatecarboxylasedeficiency pages 1-2, habarou2015pyruvatecarboxylasedeficiency pages 2-3, jasinge2024clinicalbiochemicaland pages 2-4).
• Citrate/aspartate supplementation may stabilize systemic biochemical derangements but may not normalize CSF abnormalities or neurologic outcome (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Anaplerotic therapy: triheptanoin

Concept: triheptanoin (odd-chain triglyceride) yields acetyl-CoA and propionyl-CoA; propionyl-CoA → succinyl-CoA replenishes TCA intermediates (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Evidence and outcomes - Largest cohort (n=12; 2023): overall trend toward lactate reduction in 4 of 6 analyzable subjects; only one approached statistical significance; HRQoL outcomes were mixed (lasio2023clinicalbiochemicaland pages 9-11). Authors propose possible genotype-dependent response patterns (lasio2023clinicalbiochemicaland pages 9-11). - Type C case with apparent benefit (2024): triheptanoin up-titrated to 35 mL/day (~25% daily energy) was associated with fewer hospitalizations, resolution of post-exertional hyperlactataemia, improved exercise tolerance, and improved myelination on repeat MRI at 18 months, with apparent efficacy over 2 years (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2). - Severe neonatal report (2005): a type B infant showed “immediate reversal (less than 48 h) of major hepatic failure” on triheptanoin-based anaplerotic management, but later died from severe infection (mochel2005pyruvatecarboxylasedeficiency pages 1-2).

Transplantation

Liver transplantation is referenced in the triheptanoin cohort paper as having produced partial biochemical improvement in some reports, but detailed outcomes were not extractable in the provided excerpt (lasio2023clinicalbiochemicaland pages 3-4).

Clinical trials / expanded access

ClinicalTrials.gov expanded access: NCT01461304 (“Compassionate Use of Triheptanoin (C7) for Inherited Disorders of Energy Metabolism”) explicitly includes PCD as an eligible condition. Key operational details from the record include: - First posted: 2011-10-28; last update posted: 2021-12-10 (NCT01461304 chunk 1). - Dosing described as up to 2 g/kg/24 h (up to 4 g/kg/24 h in cardiomyopathy), divided doses, with 12-month period and extension option (NCT01461304 chunk 1).

MAXO term suggestions (treatments/interventions)

• Intravenous glucose administration; correction of metabolic acidosis; dietary management; triheptanoin supplementation (anaplerotic therapy); biotin supplementation; genetic counseling; prenatal diagnosis.

Prevention

• Primary prevention: not applicable beyond carrier screening strategies.
• Secondary/tertiary prevention: rapid recognition and early metabolic management in tachypneic neonates with metabolic acidosis is emphasized (jasinge2024clinicalbiochemicaland pages 1-2).
• Genetic counseling and prenatal diagnosis: strongly emphasized; prenatal neuroradiologic abnormalities can be detected early (22w5d) and prenatal molecular testing (amniotic fluid sequencing) is feasible (xue2023casereportprenatal pages 1-2, xue2023casereportprenatal pages 5-7).

Other species / natural disease

No naturally occurring veterinary cases were retrieved in the available evidence.

Model organisms and experimental models

No PCD-specific animal model papers were retrieved in this run. Human cellular models used for diagnosis/research include patient-derived skin fibroblasts (enzyme activity assays; expression studies) and prenatal cell sources (chorionic villi/amniocytes) (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2, tsygankova2022expandingthegenetic pages 1-2, xue2023casereportprenatal pages 5-7).

Recent developments (2023–2024 highlights)

1. Largest treated cohort to date (2023): long-term triheptanoin treatment in 12 PCD patients suggests high inter-individual variability and possible genotype-dependent response, but limited statistical signal overall (lasio2023clinicalbiochemicaland pages 1-3, lasio2023clinicalbiochemicaland pages 9-11).
2. Prenatal onset documented (2023): neuroradiologic phenotype detected as early as 22w5d gestation in a genetically confirmed type B case, reinforcing prenatal diagnostic value (xue2023casereportprenatal pages 1-2).
3. New neonatal genotypes (2023–2024): multiple novel PC variants (frameshift, nonsense, missense) reported across diverse populations (Iran; Sri Lanka; China) (maryami2023insilicoanalysis pages 1-2, jasinge2024clinicalbiochemicaland pages 2-4, xue2023casereportprenatal pages 1-2).
4. Type C triheptanoin response (2024): first reported type C triheptanoin response with reduced hospitalizations and improved myelination (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).

Artifact: variants and diagnostic hallmarks with example values

Table: This table compiles representative PC variants and core diagnostic biochemical/imaging features for pyruvate carboxylase deficiency using only evidence available in the conversation. It is useful as a quick-reference artifact linking genotype classes to phenotype subtypes and concrete diagnostic values from recent case reports and series.

Evidence-based expert interpretation (authoritative analysis)

• The field consensus remains that disease-modifying therapy is lacking and supportive care predominates, especially for types A/B where early mortality is common (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2, bernhardt2024pyruvatecarboxylasedeficiency pages 1-2).
• Anaplerotic therapy is mechanistically attractive because the “primary result of the defect is a major deficit of oxaloacetate for the CAC,” but real-world outcomes are heterogeneous and may depend on genotype/domain effects and phenotype severity (mochel2005pyruvatecarboxylasedeficiency pages 1-2, lasio2023clinicalbiochemicaland pages 9-11).
• Diagnostic practice is shifting toward genome-wide sequencing plus structural/deep intronic variant analysis, because standard exon-focused approaches can miss causative alleles (tsygankova2022expandingthegenetic pages 1-2).

References (URLs and publication dates where available)

The report citations above include DOI URLs and months/years extracted from the retrieved full texts and records, including: - Lasio et al., Molecular Genetics and Metabolism (Jun 2023): https://doi.org/10.1016/j.ymgme.2023.107605 (lasio2023clinicalbiochemicaland pages 1-3) - Xue, Frontiers in Endocrinology (Jul 2023): https://doi.org/10.3389/fendo.2023.1199590 (xue2023casereportprenatal pages 1-2) - Maryami et al., Iranian Biomedical Journal (Sep 2023): https://doi.org/10.61186/ibj.27.5.307 (maryami2023insilicoanalysis pages 1-2) - Jasinge et al., Advances in Laboratory Medicine (Jan 2024): https://doi.org/10.1515/almed-2023-0102 (jasinge2024clinicalbiochemicaland pages 1-2) - Bernhardt et al., JIMD Reports (published 2024; accepted 2023-12-05; Dec 2024 issue listed): https://doi.org/10.1002/jmd2.12405 (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2) - NCT01461304 (posted 2011-10-28; updated 2021-12-10): ClinicalTrials.gov record as retrieved (NCT01461304 chunk 1)

References

1. (lasio2023clinicalbiochemicaland pages 1-3): M. Laura Duque Lasio, Angela C. Leshinski, Nicole H. Ducich, Leigh Anne Flore, April Lehman, Natasha Shur, Parul B. Jayakar, Bryan E. Hainline, Alice A. Basinger, William G. Wilson, George A. Diaz, Richard W. Erbe, Dwight D. Koeberl, Jerry Vockley, and Jirair K. Bedoyan. Clinical, biochemical and molecular characterization of 12 patients with pyruvate carboxylase deficiency treated with triheptanoin. Molecular Genetics and Metabolism, 139:107605, Jun 2023. URL: https://doi.org/10.1016/j.ymgme.2023.107605, doi:10.1016/j.ymgme.2023.107605. This article has 5 citations and is from a peer-reviewed journal.

2. (marinvalencia2010pyruvatecarboxylasedeficiency pages 1-2): Isaac Marin-Valencia, Charles R. Roe, and Juan M. Pascual. Pyruvate carboxylase deficiency: mechanisms, mimics and anaplerosis. Molecular genetics and metabolism, 101 1:9-17, Sep 2010. URL: https://doi.org/10.1016/j.ymgme.2010.05.004, doi:10.1016/j.ymgme.2010.05.004. This article has 150 citations and is from a peer-reviewed journal.

3. (bernhardt2024pyruvatecarboxylasedeficiency pages 1-2): I. Bernhardt, L. Van Dorp, M. Dixon, M. McSweeney, C. Gan, J. Baruteau, and A. Chakrapani. Pyruvate carboxylase deficiency type c; variable presentation and beneficial effect of triheptanoin. JIMD Reports, 65:10-16, Dec 2024. URL: https://doi.org/10.1002/jmd2.12405, doi:10.1002/jmd2.12405. This article has 3 citations and is from a peer-reviewed journal.

4. (xue2023casereportprenatal pages 1-2): Mei Xue. Case report: prenatal neurological injury in a neonate with pyruvate carboxylase deficiency type b. Frontiers in Endocrinology, Jul 2023. URL: https://doi.org/10.3389/fendo.2023.1199590, doi:10.3389/fendo.2023.1199590. This article has 5 citations.

5. (jasinge2024clinicalbiochemicaland pages 2-4): Eresha Jasinge, Mihika Fernando, Neluwa-Liyanage Ruwan Indika, Pyara Dilani Ratnayake, Nalin Gamaathige, Ratnanathan Ratnaranjith, Sabine Schroeder, Patricia Jones, Skrahina Volha, Subhashinie Jayasena, Anusha Varuni Gunaratna, Asitha Niroshana Bandara Ekanayake, and Arndt Rolfs. Clinical, biochemical, and molecular profiles of three sri lankan neonates with pyruvate carboxylase deficiency. Advances in Laboratory Medicine, 5:205-212, Jan 2024. URL: https://doi.org/10.1515/almed-2023-0102, doi:10.1515/almed-2023-0102. This article has 0 citations.

6. (lasio2023clinicalbiochemicaland pages 9-11): M. Laura Duque Lasio, Angela C. Leshinski, Nicole H. Ducich, Leigh Anne Flore, April Lehman, Natasha Shur, Parul B. Jayakar, Bryan E. Hainline, Alice A. Basinger, William G. Wilson, George A. Diaz, Richard W. Erbe, Dwight D. Koeberl, Jerry Vockley, and Jirair K. Bedoyan. Clinical, biochemical and molecular characterization of 12 patients with pyruvate carboxylase deficiency treated with triheptanoin. Molecular Genetics and Metabolism, 139:107605, Jun 2023. URL: https://doi.org/10.1016/j.ymgme.2023.107605, doi:10.1016/j.ymgme.2023.107605. This article has 5 citations and is from a peer-reviewed journal.

7. (mochel2005pyruvatecarboxylasedeficiency pages 1-2): Fanny Mochel, Pascale DeLonlay, Guy Touati, Henri Brunengraber, Renee P. Kinman, Daniel Rabier, Charles R. Roe, and Jean-Marie Saudubray. Pyruvate carboxylase deficiency: clinical and biochemical response to anaplerotic diet therapy. Molecular genetics and metabolism, 84 4:305-12, Apr 2005. URL: https://doi.org/10.1016/j.ymgme.2004.09.007, doi:10.1016/j.ymgme.2004.09.007. This article has 178 citations and is from a peer-reviewed journal.

8. (wang2008themolecularbasis pages 1-2): Dong Wang, Hong Yang, Kevin C. De Braganca, Jiesheng Lu, Ling Yu Shih, Paz Briones, Tim Lang, and Darryl C. De Vivo. The molecular basis of pyruvate carboxylase deficiency: mosaicism correlates with prolonged survival. Molecular genetics and metabolism, 95 1-2:31-8, Sep 2008. URL: https://doi.org/10.1016/j.ymgme.2008.06.006, doi:10.1016/j.ymgme.2008.06.006. This article has 51 citations and is from a peer-reviewed journal.

9. (NCT01461304 chunk 1): Jerry Vockley, MD, PhD. Compassionate Use of Triheptanoin (C7) for Inherited Disorders of Energy Metabolism. Jerry Vockley, MD, PhD. ClinicalTrials.gov Identifier: NCT01461304

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