ORPHA:3198
Stiff person spectrum disorder
Also known as: Moersch-Woltman syndrome · SMS · SPS · Stiff man spectrum disorder
Publications
3,079
94.6th percentile
Trials
12
Interventional, condition-specific
Researchers
846
Distinct authors in sample
Gene link
—
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare neurological disorder comprising fluctuating trunk and limb stiffness, painful muscle spasms, task-specific phobia related to walking, an exaggerated startle response, and often ankylosing deformities such as fixed lumbar hyperlordosis.
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:0008491
- MeSH:D016750
- OMIM:184850
- UMLS:C0085292
- NCIT:C85170
Additional Mondo synonyms (4)
Stiff Person Syndrome · Stiff Person syndrome · Stiff-man syndrome · stiff-person syndrome
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
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
3,079 matched papers (1,527 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
12 matched on ClinicalTrials.gov (5 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?
Not yet — the cause hasn't been pinned down in GenCC.
No strong gene–disease assertion joined for this Orphanet entity.
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?
3,079
3,079 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.
3,079 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).
1,527 in the last 10 years · medium confidence · 94.6th percentile (publications denominator)
Phrase hits: 3,079 · MeSH hits: 0
Who's working on it?
846
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.
- 01Dalakas MC10 papers · 2026
Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA. marinos.dalakas@jefferson.edu.
Papers in Europe PMC - 02Newsome SD8 papers · 2026
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
Papers in Europe PMC - 03Wang Y6 papers · 2026
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
Papers in Europe PMC - 04Li J5 papers · 2026
Department of Gastroenterology Chinese Academy of Medical Sciences & Peking Union Medical College Hospital Beijing China.
Papers in Europe PMC - 05Dubey D4 papers · 2026
Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
Papers in Europe PMC - 06Sivak S4 papers · 2026
Neurology Department University Hospital Martin, Jessenius Faculty of Medicine Martin, Comenius University Bratislava, Kollarova 2, Martin, 036 01, Slovakia.
Papers in Europe PMC - 07Skacik P4 papers · 2026
Neurology Department University Hospital Martin, Jessenius Faculty of Medicine Martin, Comenius University Bratislava, Kollarova 2, Martin, 036 01, Slovakia. skacik1@uniba.sk.
Papers in Europe PMC - 08Brighina F3 papers · 2026
Department of Biomedicine, Neuroscience, and Advanced Diagnostic (BIND), University of Palermo, Via del Vespro 143, 90129, Palermo, Italy.
Papers in Europe PMC - 09Chen HR3 papers · 2025
Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Papers in Europe PMC - 10Di Stefano V3 papers · 2026
Department of Biomedicine, Neuroscience, and Advanced Diagnostic (BIND), University of Palermo, Via del Vespro 143, 90129, Palermo, Italy. vincenzo.distefano07@unipa.it.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
12
interventional trials for this specific condition
12 interventional trials matched this specific condition name; 5 currently recruiting in our sample.
Data as of 27 July 2026
12 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 92.5th percentile).
medium confidence · 92.5th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
12 interventional trials matched after quoted-phrase search and title/condition post-filter.
- NCT06703333·NOT YET RECRUITING·Extracorporeal Photopheresis (ECP) in the Treatment of Stiff Person Syndrome (OPTION Study)
Conditions: Stiff Person Syndrome·Matched via name phrase
- NCT06528392·NOT YET RECRUITING·Efgartigimod for Stiff Person Syndrome (ESPS)
Conditions: Stiff-Person Syndrome·Matched via name phrase
- NCT06375993·ENROLLING BY INVITATION·A Phase 1 Study of Prulacabtagene Leucel (Prula-cel, Formerly ADI-001) in Autoimmune Disease
Conditions: Lupus Nephritis · Autoimmune Diseases · Systemic Sclerosis (SSc) · Systemic Lupus Erythematosus (SLE)·Matched via name phrase
- NCT07341828·NOT YET RECRUITING·A Study of C-CAR168 in the Treatment of Central Nervous System Autoimmune Diseases Refractory to Standard Therapy
Conditions: Multiple Sclerosis (MS) · Neuromyelitis Optica Spectrum Disorders (NMOSD) · Autoimmune Encephalitis · Stiff Person Syndrome·Matched via name phrase
- NCT07552987·NOT YET RECRUITING·A Study Investigating Intravenous Human Normal Immune Globulin 10% in Adults With Stiff Person Syndrome
Conditions: Stiff Person Syndrome·Matched via name phrase
Observational and natural-history studies
5 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
- NCT06502015·RECRUITING·Biomarkers in Autoimmune Disease of Nervous System
Conditions: Autoimmune Diseases of the Nervous System · Neuromyelitis Optica Spectrum Disorder · Multiple Sclerosis · Guillain-Barre Syndrome·Matched via name phrase
- NCT07403188·RECRUITING·A Long-Term Follow-Up Study for Participants Previously Treated With KYV-101
Conditions: Refractory Lupus Nephritis · Myasthaenia Gravis · Stiff Person Syndrome · Rheumatoid Arthritis (RA)·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 2026-07-26This 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.
"Stiff person spectrum disorder" OR "Moersch-Woltman syndrome" OR "Stiff man spectrum disorder" OR "Stiff Person Syndrome" OR "Stiff-man syndrome" OR "stiff-person syndrome"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Stiff person spectrum disorder" OR "Moersch-Woltman syndrome" OR "Stiff man spectrum disorder" OR "Stiff Person Syndrome" OR "Stiff-man syndrome" OR "stiff-person syndrome"
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: 12 interventional · 5 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
Synonyms dropped by stoplist: SMS; SPS
Confidence reasoning
- Preferred label is multi-word and distinctive
- 2 synonym(s) dropped by stoplist (may under-count)
- No label/synonym collisions with other diseases in this corpus
Ingested 2026-07-26T22:27:43.947Z