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ORPHA:26

Methylmalonic acidemia with homocystinuria

low confidenceDisorder

Also known as: Combined defect in adenosylcobalamin and methylcobalamin synthesis · Methylmalonic aciduria with homocystinuria

Publications

1,902

Trials

0

Interventional, condition-specific

Researchers

1,328

Distinct authors in sample

Gene link

THAP11, ZNF143

Limited

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

A rare inborn error of vitamin B12 (cobalamin) metabolism characterized by megaloblastic anemia, lethargy, , , intellectual deficit and . There are four complementation classes of cobalamin defects (cblC, cblD, cblF and cblJ) that are responsible for methylmalonic acidemia - homocystinuria (methylmalonic acidemia - homocystinuria cblC, cblD cblF and cblJ).

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 (2)

combined defect in adenosylcobalamin and methylcobalamin synthesis · methylmalonic aciduria with homocystinuria

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.”

5/6 stages with a signal

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

  1. Gene identifiedPresent

    Limited — THAP11, ZNF143

  2. LiteraturePresent

    1,902 matched papers (1,384 in last 10 years) Source

  3. Phenotype characterisedPresent

    326 HPO annotations (e.g. Methylmalonic acidemia; Methylmalonic aciduria; Elevated circulating palmitoleylcarnitine concentration) Source

  4. Animal modelPresent

    4 genotype models (Mus musculus, Danio rerio) Source

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  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?

Possibly — only limited evidence so far for THAP11, ZNF143.

GenCC classification: Limited.

Phenotypes (Monarch / HPO)

326

Associated phenotypes · MONDO:0016826

  • Methylmalonic acidemia
  • Methylmalonic aciduria
  • Elevated circulating palmitoleylcarnitine concentration
  • Glossitis
  • Optic atrophy

Showing 5 of 326 — open Monarch for the full list.

Animal models (Monarch / Alliance)

4

Model associations linked to this Mondo ID

Monarch fetch 2026-07-29

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

1 associated chemical · 20 pathways. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • Hydroxocobalamin · therapeutic

Pathways: Peroxisome; Vitamin digestion and absorption; Metabolism; Disease; Cobalamin (Cbl, vitamin B12) transport and metabolism; Metabolism of water-soluble vitamins and cofactors; Metabolism of vitamins and cofactors; Generic Transcription Pathway

MyDisease.info · MONDO:0016826

Literature

Is anyone studying this?

1,902

1,902 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

1,902 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

1,384 in the last 10 years · low confidence

Phrase hits: 571 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,328

Distinct author names in 200 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
    Zhang Y10 papers · 2026

    Department of Obstetrics and Gynecology, the First Affiliated Hospital of Soochow University, Suzhou 215006, China.

    Papers in Europe PMC
  2. 02
    Chen Y9 papers · 2025

    Department of Endocrinology and Metabolism, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou, 450006, China.

    Papers in Europe PMC
  3. 03
    Zhang H9 papers · 2026

    Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 KongJiang Road, Shanghai, 200092, China.

    Papers in Europe PMC
  4. 04
    Quintana AM7 papers · 2026

    Department of Biology, University of Texas Arlington, Arlington, TX, USA.

    Papers in Europe PMC
  5. 05
    Wang Y7 papers · 2026

    Heze Maternity and Child Healthcare Hospital, Heze, 274032, China.

    Papers in Europe PMC
  6. 06
    Guertin MJ6 papers · 2026

    Center for Cell Analysis and Modeling, University of Connecticut, 400 Farmington Avenue, Farmington, CT, USA; Department of Genetics and Genome Sciences, University of Connecticut, 400 Farmington Avenue, Farmington, CT, USA.

    Papers in Europe PMC
  7. 07
    Castro VL5 papers · 2026

    Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA.

    Papers in Europe PMC
  8. 08
    Chen T5 papers · 2026

    Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 KongJiang Road, Shanghai, 200092, China.

    Papers in Europe PMC
  9. 09
    Chen Z5 papers · 2026

    Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China.

    Papers in Europe PMC
  10. 10
    Froese DS5 papers · 2026

    Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, University of Zürich, Switzerland. Electronic address: sean.froese@kispi.uzh.ch.

    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 on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present). 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 11 September 2026 · last trial check 11 September 2026

No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.

low confidence · 38.6th 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

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-29

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for Methylmalonic acidemia with homocystinuria — check Associations / patient organisations on that page.

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.

("Methylmalonic acidemia with homocystinuria" OR "Combined defect in adenosylcobalamin and methylcobalamin synthesis" OR "Methylmalonic aciduria with homocystinuria") OR ("THAP11" OR "THAP11 syndrome" OR "THAP11-related" OR "ZNF143" OR "ZNF143 syndrome" OR "ZNF143-related")

Run this search on Europe PMC

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

"Methylmalonic acidemia with homocystinuria" OR "Combined defect in adenosylcobalamin and methylcobalamin synthesis" OR "Methylmalonic aciduria with homocystinuria"

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

Parent-category trials query:

"methylmalonic acidemia"

Query health: ok — strategies attempted: phrase; with hits: phrase

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
  • Publication count (1902) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-26T12:08:30.227Z