ORPHA:85165
Severe achondroplasia-developmental delay-acanthosis nigricans syndrome
Also known as: SADDAN
Publications
148
59.5th percentile
Trials
0
Interventional, condition-specific
Researchers
881
Distinct authors in sample
Gene link
FGFR3
Strong
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
Severe achondroplasia--acanthosis nigricans syndrome is characterised by the association of severe achondroplasia with and acanthosis nigricans. It has been described in four unrelated individuals. Structural central nervous system anomalies, and hearing loss were also reported, together with bowing of the clavicle, femur, tibia and fibula in some cases. The syndrome is caused by a Lys650Met substitution in the kinase domain of fibroblast growth factor receptor 3 (encoded by the FGFR3 gene; 4p16.3).
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:0014658
- OMIM:616482
- UMLS:C2674173
Additional Mondo synonyms (1)
SADDAN dysplasia
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
Strong — FGFR3
- LiteraturePresent
148 matched papers (68 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 (FGFR3).
GenCC classification: Strong.
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?
148
148 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.
148 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).
68 in the last 10 years · high confidence · 59.5th percentile (publications denominator)
Phrase hits: 148 · MeSH hits: 0
Who's working on it?
881
Distinct author names in 148 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.
- 01Morales-Saldaña S8 papers · 2026
Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, 58190, Morelia, México.
Papers in Europe PMC - 02Krejci P7 papers · 2022
Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA. pavel.krejci@cshs.org
Papers in Europe PMC - 03Donoghue DJ6 papers · 2014Papers in Europe PMC
- 04Ornelas JF6 papers · 2026
Red de Biología Evolutiva, Instituto de Ecología, A.C. (INECOL), Xalapa, Veracruz, Mexico.
Papers in Europe PMC - 05Wilcox WR6 papers · 2014
Department of Human Genetics, Emory University Atlanta, Georgia, 30322 ; Medical Genetics Institute, Cedars-Sinai Medical Center Los Angeles, California ; Department of Pediatrics, UCLA School of Medicine Los Angeles, California.
Papers in Europe PMC - 06Chen L5 papers · 2025
Center of Bone Metabolism and Repair, Department of Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China.
Papers in Europe PMC - 07Francomano CA5 papers · 2001Papers in Europe PMC
- 08Krakow D5 papers · 2026
Departments of Obstetrics and Gynecology, Orthopaedic Surgery and Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA.
Papers in Europe PMC - 09Vásquez-Aguilar AA5 papers · 2026
Red de Biología Evolutiva, Instituto de Ecología, A.C. (INECOL), Xalapa, Veracruz, Mexico.
Papers in Europe PMC - 10Bellus GA4 papers · 2000
Department of Dermatology, University of Colorado School of Medicine, Denver, CO 80262, USA. gary.bellus@uchsc.edu
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).
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 2026-07-26This 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.
"Severe achondroplasia-developmental delay-acanthosis nigricans syndrome" OR "SADDAN" OR "SADDAN dysplasia"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Severe achondroplasia-developmental delay-acanthosis nigricans syndrome" OR "SADDAN" OR "SADDAN dysplasia"
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
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
Ingested 2026-07-27T02:46:04.503Z