ORPHA:168598
Methionine adenosyltransferase I/III deficiency
Also known as: MAT I/III deficiency · Mudd's disease
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
205
69.6th percentile
Trials
1
Interventional, condition-specific
Researchers
1,290
Distinct authors in sample
Gene link
MAT1A
Definitive
Readiness
3/6
Stages with a signal
Clinical definition (Orphanet)
A rare inborn error of metabolism characterized by persistently elevated serum methionine levels. Half of patients reported with MAT I/III deficiency, notably those with hypermethioninemia below 800 µM, have no CNS abnormalities and are clinically asymptomatic. However, individuals with higher levels might show evidence of central nervous system abnormalities, most notably hypo- or demyelination on brain MRI, as well as and . Bad breath or a strong smell of urine and sweat may be noted in some patients.
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:0009607
- OMIM:250850
- UMLS:C0268621
- NCIT:C123435
Additional Mondo synonyms (6)
MAT deficiency · brain demyelination due to methionine adenosyltransferase deficiency · hypermethioninemia, persistent, autosomal dominant, due to methionine adenosyltransferase I/III deficiency · isolated persistent hypermethioninemia · methionine adenosyltransferase deficiency · methionine adenosyltransferase deficiency, autosomal recessive
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
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedPresent
Definitive — MAT1A
- LiteraturePresent
205 matched papers (121 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 trialPresent
1 matched on ClinicalTrials.gov
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 (MAT1A).
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?
205
205 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.
205 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).
121 in the last 10 years · medium confidence · 69.6th percentile (publications denominator)
Phrase hits: 205 · MeSH hits: 0
Who's working on it?
1,290
Distinct author names in 200 sampled papers — named people below.
Who's working on it?
People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.
- 01Mudd SH20 papers · 2015
Laboratory of Molecular Biology, National Institute of Mental Health, Bethesda, MD 20892, USA. muddh@mail.nih.gov
Papers in Europe PMC - 02Blom HJ11 papers · 2020
Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, University Medical Centre Freiburg, Freiburg im Breisgau, Germany.
Papers in Europe PMC - 03Allen RH8 papers · 2017
Division of Hematology, Department of Medicine, University of Colorado School of Medicine, 12700 E. 19th Avenue, Room 9122, Bldg. RC2, Campus Box B170, Aurora, CO, USA.
Papers in Europe PMC - 04Couce ML7 papers · 2024
Unidad de Trastornos Metabólicos, Departamento de Pediatría, Hospital Clínico Universitario, Santiago de Compostela, Spain.
Papers in Europe PMC - 05Tangerman A7 papers · 2018
Department of Internal Medicine, RUNMC, Nijmegen, The Netherlands.
Papers in Europe PMC - 06Wagner C7 papers · 2015
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tn, USA.
Papers in Europe PMC - 07Kožich V6 papers · 2021
Institute of Inherited Metabolic Disorders, Charles University in Prague-First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic.
Papers in Europe PMC - 08Levy HL6 papers · 2003Papers in Europe PMC
- 09Stabler SP6 papers · 2017
Division of Hematology, Department of Medicine, University of Colorado School of Medicine, 12700 E. 19th Avenue, Room 9122, Bldg. RC2, Campus Box B170, Aurora, CO, USA. Sally.Stabler@ucdenver.edu.
Papers in Europe PMC - 10Zhang Y6 papers · 2024
Department of Neurology, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
1
interventional trials for this specific condition
1 interventional trial matched this specific condition name; none in our sample are currently recruiting.
Data as of 27 July 2026
1 interventional trial — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 76.8th percentile).
medium confidence · 76.8th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
1 interventional trials matched after quoted-phrase search and title/condition post-filter.
No currently recruiting studies in the matched set. Open the same 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 2026-07-26This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.
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.
"Methionine adenosyltransferase I/III deficiency" OR "MAT I/III deficiency" OR "Mudd's disease" OR "MAT deficiency" OR "brain demyelination due to methionine adenosyltransferase deficiency" OR "hypermethioninemia, persistent, autosomal dominant, due to methionine adenosyltransferase I/III deficiency" OR "isolated persistent hypermethioninemia" OR "methionine adenosyltransferase deficiency" OR "methionine adenosyltransferase deficiency, autosomal recessive"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Methionine adenosyltransferase I/III deficiency" OR "MAT I/III deficiency" OR "Mudd's disease" OR "MAT deficiency" OR "brain demyelination due to methionine adenosyltransferase deficiency" OR "hypermethioninemia, persistent, autosomal dominant, due to methionine adenosyltransferase I/III deficiency" OR "isolated persistent hypermethioninemia" OR "methionine adenosyltransferase deficiency" OR "methionine adenosyltransferase deficiency, autosomal recessive" OR "MAT1A"
Recall-expansion terms: MAT1A
Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).
Study-type breakdown: 1 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
- Publication count (205) is high for prevalence class "<1 / 1 000 000" — confidence capped at medium
Ingested 2026-07-27T08:28:49.501Z