ORPHA:280183
Methylmalonic aciduria due to transcobalamin receptor defect
Also known as: Methylmalonic acidemia, TCb1R type · Methylmalonic acidemia, TCbIR type
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
4
17.7th percentile
Trials
0
Interventional, condition-specific
Researchers
48
Distinct authors in sample
Gene link
CD320
Definitive
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
Methylmalonic aciduria due to transcobalamin receptor defect is a rare metabolite absorption and transport disorder characterized by a moderate increase of methylmalonic acid (MMA) in the blood and urine due to decreased cellular uptake of cobalamin resulting from decreased transcobalamin receptor function. Patients are usually asymptomatic however, screening reveals increased C3-acylcarnitine and MMA in plasma. Serum homocysteine levels may vary from normal to moderately elevated and retinal vascular occlusive disease, resulting in severe visual loss, has been reported.
How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0013341
- OMIM:613646
- UMLS:C4749905
Additional Mondo synonyms (5)
CD320 methylmalonic acidemia · methylmalonic acidemia caused by mutation in CD320 · methylmalonic acidemia, TCb1R type · methylmalonic acidemia, TCbIR type · methylmalonic aciduria due to transcobalamin receptor defect
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.”
2/6 stages with a signal
No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.
- Gene identifiedPresent
Definitive — CD320
- LiteraturePresent
4 matched papers (4 in last 10 years) Source
- Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
- Animal modelNot checked
Not yet enriched from Monarch / Alliance
- Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
- Interventional trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
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 (CD320).
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?
4
4 papers have ever been indexed 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.
4 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).
4 in the last 10 years · high confidence · 17.7th percentile (publications denominator)
Phrase hits: 4 · MeSH hits: 0
Who's working on it?
48
Distinct author names in 4 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.
- 01Shukla PK2 papers · 2025
Department of Computer Science & Engineering , University Institute of Technology, Rajiv Gandhi Proudyogiki Vishwavidyalaya (State Technological University), Bhopal, Madhya Pradesh, India.
Papers in Europe PMC - 02Abugabah A1 paper · 2025
College of Technological Innovation, Zayed University, Abu Dhabi, United Arab Emirates.
Papers in Europe PMC - 03Alagia M1 paper · 2025
Department of Translational Medicine, University of Naples "Federico II", Naples, Italy.
Papers in Europe PMC - 04Albano L1 paper · 2025
CEINGE Advanced Biotechnologies Franco Salvatore, Naples, Italy.
Papers in Europe PMC - 05
- 06Awada H1 paper · 2025
UMRS Inserm 1256 nGERE (Nutrition-Genetics-Environmental Risks), Institute of Medical Research (Pôle BMS), University of Lorraine, Nancy, France.
Papers in Europe PMC - 07Barretta F1 paper · 2025
Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy.
Papers in Europe PMC - 08Brunetti-Pierri N1 paper · 2025
Department of Translational Medicine, University of Naples "Federico II", Naples, Italy.
Papers in Europe PMC - 09Cacchiarelli D1 paper · 2025
Department of Translational Medicine, University of Naples "Federico II", Naples, Italy. davide.cacchiarelli@unina.it.
Papers in Europe PMC - 10
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).
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.
See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
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 2026-07-26Likely 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 aciduria due to transcobalamin receptor defect" OR "Methylmalonic acidemia, TCb1R type" OR "Methylmalonic acidemia, TCbIR type" OR "CD320 methylmalonic acidemia" OR "methylmalonic acidemia caused by mutation in CD320"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Methylmalonic aciduria due to transcobalamin receptor defect" OR "Methylmalonic acidemia, TCb1R type" OR "Methylmalonic acidemia, TCbIR type" OR "CD320 methylmalonic acidemia" OR "methylmalonic acidemia caused by mutation in CD320" OR "CD320"
Recall-expansion terms: CD320
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: suspect — strategies attempted: phrase, recall-expansion; 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
Ingested 2026-07-27T11:50:16.113Z