ORPHA:394
Homocystinuria due to cystathionine beta-synthase deficiency
Also known as: CBS-deficient HCU · Classical homocystinuria · Cystathionine beta-synthase deficiency · Cystathionine beta-synthase-deficient homocystinuria · Homocystinuria due to CBS deficiency
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
731
87.6th percentile
Trials
5
Interventional, condition-specific
Researchers
1,213
Distinct authors in sample
Gene link
CBS
Definitive
Readiness
3/6
Stages with a signal
Clinical definition (Orphanet)
A rare disease of methionine catabolism characterized by accumulation of methionine and homocysteine with clinical involvement of the eye, skeletal system, vascular system and central nervous system (CNS).
How rare: 1-9 / 1 000 000 — roughly one to nine people per million. In a city the size of Kolkata, perhaps a few dozen.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0009352
- OMIM:236200
- UMLS:C0751202
Additional Mondo synonyms (6)
Homocystinuria due to Cystathionine Beta-Synthase Deficiency · classic homocystinuria · cystathionine beta-synthase deficiency · homocystinuria due to cystathionine beta-synthase deficiency · homocystinuria, B6-responsive and nonresponsive types · thrombosis, hyperhomocysteinemic
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 — CBS
- LiteraturePresent
731 matched papers (380 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
5 matched on ClinicalTrials.gov (3 recruiting in sample)
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 (CBS).
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?
731
731 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=5449) is 41.
731 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).
380 in the last 10 years · high confidence · 87.6th percentile (publications denominator)
Phrase hits: 731 · MeSH hits: 0
Who's working on it?
1,213
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.
- 01Majtan T11 papers · 2026
Section of Genetics and Metabolism, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
Papers in Europe PMC - 02Kožich V6 papers · 2025
Department of Pediatrics and Inherited Metabolic Disorders, Charles University-First Faculty of Medicine and General University Hospital in Prague, Prague, Czechia.
Papers in Europe PMC - 03Kruger WD6 papers · 2024
Cancer Signaling and Microenvironment Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA.
Papers in Europe PMC - 04Stabler SP6 papers · 2024
Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA.
Papers in Europe PMC - 05Karaca M5 papers · 2026
Aksaray University, Faculty of Science and Arts, Department of Biology, Aksaray, Turkey.
Papers in Europe PMC - 06Levy HL5 papers · 2026
Division of Genetics, Children's Hospital's, Boston, MA 02115, USA. harvey.levy@tch.harvard.edu
Papers in Europe PMC - 07Schwartz IVD5 papers · 2024
Graduate Program in Medical Sciences, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
Papers in Europe PMC - 08
- 09Yap S5 papers · 2003
National Centre for Inherited Metabolic Disorders, Children's Hospital, Dublin, Ireland.
Papers in Europe PMC - 10Allen RH4 papers · 2017
Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
5
interventional trials for this specific condition
5 interventional trials matched this specific condition name; 3 currently recruiting in our sample. 8 trials are registered for homocystinuria, the broader category — shown separately because they may or may not enrol this specific subtype.
Data as of 27 July 2026
5 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 87.9th percentile).
high confidence · 87.9th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
5 interventional trials matched after quoted-phrase search and title/condition post-filter.
- NCT06247085·RECRUITING·A Study to Investigate Efficacy and Safety of Pegtibatinase Compared With Placebo in Participants ≥12 to ≤65 Years of Age With Classical Homocystinuria (HCU) Due to Cystathionine Beta Synthase Deficiency Receiving Standard of Care Treatment
Conditions: Homocystinuria·Matched via name phrase
- NCT06622577·NOT YET RECRUITING·The Effect of Dietary Management and Cysteine Supplementation on Growth Parameters and Biochemical Control for Pediatric Qatari Patients Affected with Classical B6 Non-responsive Homocystinuria.
Conditions: Classical Homocystinuria·Matched via name phrase
- NCT06431893·ENROLLING BY INVITATION·A Long-term Extension Study to Assess the Long-term Safety and Efficacy of Pegtibatinase Treatment in Participants ≥5 to ≤65 Years of Age With Classical Homocystinuria (HCU) (ENSEMBLE)
Conditions: Homocystinuria·Matched via name phrase
Broader category: homocystinuria
8
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.
Observational and natural-history studies
3 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
- NCT02998710·RECRUITING·Natural History Study of Homocystinuria Caused by Cystathionine Beta-Synthase Deficiency (ACAPPELLA)
Conditions: Homocystinuria Due to CBS Deficiency·Matched via name phrase
- NCT06556615·RECRUITING·Health Related Quality of Life (HrQoL) in Classical Homocystinuria (CBS Deficiency)
Conditions: Homocystinuria·Matched via name phrase
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 2026-07-26Directly listed under NPRD Group 2.
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.
"Homocystinuria due to cystathionine beta-synthase deficiency" OR "CBS-deficient HCU" OR "Classical homocystinuria" OR "Cystathionine beta-synthase deficiency" OR "Cystathionine beta-synthase-deficient homocystinuria" OR "Homocystinuria due to CBS deficiency" OR "classic homocystinuria" OR "homocystinuria, B6-responsive and nonresponsive types" OR "thrombosis, hyperhomocysteinemic"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Homocystinuria due to cystathionine beta-synthase deficiency" OR "CBS-deficient HCU" OR "Classical homocystinuria" OR "Cystathionine beta-synthase deficiency" OR "Cystathionine beta-synthase-deficient homocystinuria" OR "Homocystinuria due to CBS deficiency" OR "classic homocystinuria" OR "homocystinuria, B6-responsive and nonresponsive types" OR "thrombosis, hyperhomocysteinemic" OR "CBS"
Recall-expansion terms: CBS
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: 5 interventional · 3 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"homocystinuria"
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 2026-07-26T13:41:55.461Z