Component
MMACHC gene transcription
MMACHC gene transcription
2 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
What acts on it
In CHU-12122 epi-cblC fibroblasts, the promoter-hypermethylated paternal MMACHC allele was transcriptionally silent; only the maternal coding-mutant allele was detected in transcripts.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- cross_nutrient
- false
- evidence_location
- Results: Figures 1, 4–6; Methods: PRDX1 silencing
- experimental_model
- Allele-specific human epi-cblC expression and bisulfite analysis
- exposure
- Paternal secondary epimutation plus maternal c.270_271insA coding variant
- limitations
- Family-specific compound genetic/epigenetic machinery defect; not a nutritional methylation intervention.
- nutrient_topic
- Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
- organism
- Homo sapiens
- plain_language
- The intact B12-processing allele was switched off by the inherited epigenetic defect.
- primary_references
- [gueant-2018-epi-cblc] A PRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients (2018). https://pubmed.ncbi.nlm.nih.gov/29302025/ DOI: 10.1038/s41467-017-02306-5
- tissue_or_cell_type
- CHU-12122 fibroblasts
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 921–933
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Allele-specific human epi-cblC expression and bisulfite analysis · source_derived_draft · unverified_draft
### b12-mmachc-epi-silencing In CHU-12122 epi-cblC fibroblasts, the promoter-hypermethylated paternal MMACHC allele was transcriptionally silent; only the maternal coding-mutant allele was detected in transcripts. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The intact B12-processing allele was switched off by the inherited epigenetic defect. organism: Homo sapiens tissue_or_cell_type: CHU-12122 fibroblasts experimental_model: Allele-specific human epi-cblC expression and bisulfite analysis limitations: Family-specific compound genetic/epigenetic machinery defect; not a nutritional methylation intervention. exposure: Paternal secondary epimutation plus maternal c.270_271insA coding variant cross_nutrient: false evidence_location: Results: Figures 1, 4–6; Methods: PRDX1 silencing [gueant-2018-epi-cblc] A PRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients (2018). https://pubmed.ncbi.nlm.nih.gov/29302025/ DOI: 10.1038/s41467-017-02306-5
Complete structured claim and evidencePRDX1-targeting siRNA restored detectable MMACHC expression in WG3838 epi-cblC fibroblasts, unlike control siRNA.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- cross_nutrient
- false
- evidence_location
- Results: Figures 1, 4–6; Methods: PRDX1 silencing
- experimental_model
- Human WG3838 fibroblast siRNA and quantitative RT-PCR
- exposure
- PRDX1-targeting versus control siRNA
- limitations
- Expression rescue is not demonstrated clinical treatment or proof of complete metabolic correction; MeWo-LC1 methylation endpoint is a different experiment.
- nutrient_topic
- Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
- organism
- Homo sapiens
- plain_language
- Reducing the abnormal neighboring transcript allowed the processing gene to be expressed again.
- primary_references
- [gueant-2018-epi-cblc] A PRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients (2018). https://pubmed.ncbi.nlm.nih.gov/29302025/ DOI: 10.1038/s41467-017-02306-5
- tissue_or_cell_type
- Patient fibroblasts
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 935–947
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human WG3838 fibroblast siRNA and quantitative RT-PCR · source_derived_draft · unverified_draft
### b12-prdx1-sirna-restores-mmachc PRDX1-targeting siRNA restored detectable MMACHC expression in WG3838 epi-cblC fibroblasts, unlike control siRNA. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Reducing the abnormal neighboring transcript allowed the processing gene to be expressed again. organism: Homo sapiens tissue_or_cell_type: Patient fibroblasts experimental_model: Human WG3838 fibroblast siRNA and quantitative RT-PCR limitations: Expression rescue is not demonstrated clinical treatment or proof of complete metabolic correction; MeWo-LC1 methylation endpoint is a different experiment. exposure: PRDX1-targeting versus control siRNA cross_nutrient: false evidence_location: Results: Figures 1, 4–6; Methods: PRDX1 silencing [gueant-2018-epi-cblc] A PRDX1 mutant allele causes a MMACHC secondary epimutation in cblC patients (2018). https://pubmed.ncbi.nlm.nih.gov/29302025/ DOI: 10.1038/s41467-017-02306-5
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.