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ORPHA:369962

Methylmalonic acidemia with homocystinuria, type cblX

low confidenceSubtype of disorder

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

Publications

2,253

Trials

0

Interventional, condition-specific

Researchers

0

Distinct authors in sample

Gene link

HCFC1

Definitive

Readiness

5/6

Stages with a signal

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.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (3)

combined defect in adenosylcobalamin and methylcobalamin synthesis, type cblX · methylmalonic aciduria and homocysteinemia, cblx type, X-linked recessive · methylmalonic aciduria with homocystinuria, type cblX

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

    Definitive — HCFC1

  2. LiteraturePresent

    2,253 matched papers (1,159 in last 10 years) Source

  3. Phenotype characterisedPresent

    18 HPO annotations (e.g. Hypsarrhythmia; Short stature; Choreoathetosis) Source

  4. Animal modelPresent

    1 genotype model (Mus musculus) 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?

Yes — we know a specific gene responsible (HCFC1).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

18

Associated phenotypes · MONDO:0010657

  • Hypsarrhythmia
  • Short stature
  • Choreoathetosis
  • Seizure
  • Chorea

Showing 5 of 18 — open Monarch for the full list.

Animal models (Monarch / Alliance)

1

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)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

2,253

2,253 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.

2,253 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).

1,159 in the last 10 years · low confidence

Phrase hits: 0 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

0

Distinct author names in 0 sampled papers.

Who's working on it?

No author names could be extracted from the sampled publications. Try the Europe PMC query in “How we counted this,” or contact an umbrella rare-disease organisation for researcher referrals.

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 2026-07-30

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, type cblX — 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, type cblX" OR "Combined defect in adenosylcobalamin and methylcobalamin synthesis, type cblX" OR "Methylmalonic aciduria with homocystinuria, type cblX" OR "methylmalonic aciduria and homocysteinemia, cblx type, X-linked recessive") OR (MESH:"Mental Retardation, X-Linked 3") OR ("HCFC1" OR "HCFC1 syndrome" OR "HCFC1-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Mental Retardation, X-Linked 3

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

"Methylmalonic acidemia with homocystinuria, type cblX" OR "Combined defect in adenosylcobalamin and methylcobalamin synthesis, type cblX" OR "Methylmalonic aciduria with homocystinuria, type cblX" OR "methylmalonic aciduria and homocysteinemia, cblx type, X-linked recessive" OR "Mental Retardation, X-Linked 3"

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, mesh; with hits: none

Parent literature probe: methylmalonic aciduria and homocystinuria (MONDO:0016826) — 448 hits

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 (2253) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T14:51:35.984Z