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ORPHA:27

Vitamin B12-unresponsive methylmalonic acidemia

high confidenceDisorder

Also known as: Methylmalonyl-CoA mutase deficiency · Methylmalonyl-Coenzyme A mutase deficiency · Vitamin B12-unresponsive methylmalonic aciduria

Publications

145

63.3th percentile

Trials

0

Interventional, condition-specific

Researchers

989

Distinct authors in sample

Gene link

MMUT

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

Vitamin B12-unresponsive methylmalonic acidemia is an inborn error of vitamin B12 (cobalamin) metabolism characterized by recurrent ketoacidotic crises or transient vomiting, dehydration, and intellectual deficit, which does not respond to administration of vitamin B12. There are two types of vitamin B12-unresponsive methylmalonic acidemia: mut0 and mut-.

How rare: How common this is has not been clearly measured.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (5)

methylmalonic acidemia due to methylmalonyl-CoA mutase deficiency · methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency · methylmalonyl-CoA mutase deficiency · methylmalonyl-Coenzyme A mutase deficiency · vitamin B12-unresponsive methylmalonic aciduria

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

3/6 stages with a signal

No specific-condition interventional trial, but broader-category trials exist — discuss eligibility with a clinician.

  1. Gene identifiedPresent

    Definitive — MMUT

  2. LiteraturePresent

    145 matched papers (83 in last 10 years) Source

  3. Phenotype characterisedNot checked

    Not yet enriched from Monarch / HPO

  4. Animal modelNot checked

    Not yet enriched from Monarch / Alliance

  5. Orphan designationNot checked

    FDA/EMA orphan-drug designation not enriched yet

  6. Interventional trialPartial

    None under the specific name; 15 for broader category methylmalonic acidemia

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Yes — we know a specific gene responsible (MMUT).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

Not enriched in this build — Monarch phenotype joins were not run for this record.

Animal models (Monarch / Alliance)

Not enriched in this build.

Literature

Is anyone studying this?

145

145 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.

145 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).

83 in the last 10 years · high confidence · 63.3th percentile (publications denominator)

Phrase hits: 145 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

989

Distinct author names in 145 sampled papers — named people below.

Who's working on it?

No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.

  1. 01
    Kölker S7 papers · 2025

    Division of Neuropediatrics and Inherited Metabolic Diseases, Department of General Pediatrics, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany.

    Papers in Europe PMC
  2. 02
    Baumgartner MR6 papers · 2023

    Division of Metabolism and Children's Research Center, University Children's Hospital, 8032, Zurich, Switzerland.

    Papers in Europe PMC
  3. 03
    Venditti CP6 papers · 2024

    National Human Genome Research Institute, NIH, 10 Center Drive, Building 10, Room 7S257, Bethesda, MD 20892, USA.

    Papers in Europe PMC
  4. 04
    Forny P5 papers · 2023

    Division of Metabolism and Children's Research Center, University Children's Hospital, 8032, Zurich, Switzerland.

    Papers in Europe PMC
  5. 05
    Hoffmann GF5 papers · 2025

    Division of Neuropediatrics and Inherited Metabolic Diseases, Department of General Pediatrics, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120, Heidelberg, Germany.

    Papers in Europe PMC
  6. 06
    Ledley FD5 papers · 1994

    Howard Hughes Medical Institute, Department of Cell Biology, Baylor College of Medicine, Houston, TX 77030.

    Papers in Europe PMC
  7. 07
    Chen Z4 papers · 2024

    Institute of Physiology and NCCR Kidney.CH, University of Zurich, 8057, Zurich, Switzerland.

    Papers in Europe PMC
  8. 08
    Wang Y4 papers · 2024

    New York State Department of Health, Albany, New York, USA.

    Papers in Europe PMC
  9. 09
    Berquez M3 papers · 2020

    Institute of Physiology and NCCR Kidney.CH, University of Zurich, 8057, Zurich, Switzerland.

    Papers in Europe PMC
  10. 10
    Berry GT3 papers · 2024

    Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, Massachusetts, USA.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

0

interventional trials for this specific condition

No interventional trial testing a treatment matched this specific condition name. 2 observational studies did — shown below because natural-history and cohort work can be an important step toward a trial. 15 trials are registered for methylmalonic acidemia, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 27 July 2026

No matched interventional trials. This is true for 73% of diseases in the trials denominator (5114 of 7003). Here are the researchers publishing on it.

high confidence · 36.5th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.

15 interventional trials matched methylmalonic acidemia, the broader category — listed below. Those studies are not counted in the condition-specific total.

Broader category: methylmalonic acidemia

15

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Worth raising with a clinician. How we count trials.

Recruiting under the broader category

Observational and natural-history studies

2 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

Where to find support

We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:

India — NPRD

Last verified 2026-07-26

Likely covered — the policy lists Methylmalonic acidemia as a category (Group 2), and this condition is a form of it. Confirm eligibility with a Centre of Excellence.

Group 2 — long-term / lifelong lower-cost interventions

NPRD envisages State Government support for dietary formulae, hormones, and other lower-cost interventions. This is a different route from the central CoE ₹50 lakh pathway; ask your state health department and a CoE which channel applies.

Central CoE funding may also apply depending on current rules — confirm with a notified Centre of Excellence. Do not assume the ₹50 lakh ceiling covers Group 2 by default. Verify

Centres of Excellence (15)
  • All India Institute of Medical Sciences (AIIMS) — New Delhi, Delhi
  • Maulana Azad Medical College — New Delhi, Delhi
  • Sanjay Gandhi Post Graduate Institute of Medical Sciences — Lucknow, Uttar Pradesh
  • Post Graduate Institute of Medical Education and Research (PGIMER) — Chandigarh, Chandigarh
  • Centre for DNA Fingerprinting & Diagnostics with Nizam’s Institute of Medical Sciences — Hyderabad, Telangana
  • King Edward Memorial Hospital — Mumbai, Maharashtra
  • Institute of Post-Graduate Medical Education and Research (IPGMER) — Kolkata, West Bengal
  • Centre for Human Genetics with Indira Gandhi Hospital — Bengaluru, Karnataka
  • Institute of Child Health and Hospital for Children (ICH & HC) — Chennai, Tamil Nadu
  • All India Institute of Medical Sciences (AIIMS) — Jodhpur, Rajasthan
  • Sree Avittam Thirunal Hospital (SAT), Government Medical College — Thiruvananthapuram, Kerala
  • All India Institute of Medical Sciences (AIIMS) — Bhopal, Madhya Pradesh
  • Regional Institute of Medical Sciences (RIMS) — Imphal, Manipur
  • All India Institute of Medical Sciences (AIIMS) — Patna, Bihar
  • Assam Medical College & Hospital — Dibrugarh, Assam

Voluntary contributions / crowdfunding (separate from CoE funding): https://rarediseases.mohfw.gov.in/

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

"Vitamin B12-unresponsive methylmalonic acidemia" OR "Methylmalonyl-CoA mutase deficiency" OR "Methylmalonyl-Coenzyme A mutase deficiency" OR "Vitamin B12-unresponsive methylmalonic aciduria" OR "methylmalonic acidemia due to methylmalonyl-CoA mutase deficiency" OR "methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency"

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Vitamin B12-unresponsive methylmalonic acidemia" OR "Methylmalonyl-CoA mutase deficiency" OR "Methylmalonyl-Coenzyme A mutase deficiency" OR "Vitamin B12-unresponsive methylmalonic aciduria" OR "methylmalonic acidemia due to methylmalonyl-CoA mutase deficiency" OR "methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency" OR "MMUT"

Recall-expansion terms: MMUT

Study-type breakdown: 0 interventional · 2 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"methylmalonic acidemia"

Query health: ok — strategies attempted: phrase, recall-expansion; with hits: phrase, recall-expansion

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T12:08:50.721Z