ORPHA:363654
X-linked parkinsonism-spasticity syndrome
Also known as: XPDS
Publications
1,396
Trials
0
Interventional, condition-specific
Researchers
4
Distinct authors in sample
Gene link
ATP6AP2
Strong
Readiness
3/6
Stages with a signal
Clinical definition (Orphanet)
A rare, genetic, neurological disorder characterized by parkinsonian features (including resting or action tremor, cogwheel rigidity, hypomimia and bradykinesia) associated with variably penetrant spasticity, hyperactive deep tendon reflexes and Babinski sign.
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:0010482
- OMIM:300911
- UMLS:C3806722
Additional Mondo synonyms (1)
Parkinsonism with spasticity, X-linked, X-linked 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
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 — ATP6AP2
- LiteraturePresent
1,396 matched papers (996 in last 10 years) Source
- Phenotype characterisedPresent
22 HPO annotations (e.g. Cogwheel rigidity; Mask-like facies; Spastic paraparesis) Source
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- 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 (ATP6AP2).
GenCC classification: Strong.
Phenotypes (Monarch / HPO)
22
Associated phenotypes · MONDO:0010482
- Cogwheel rigidity
- Mask-like facies
- Spastic paraparesis
- Bradykinesia
- Babinski sign
Showing 5 of 22 — open Monarch for the full list.
Animal models (Monarch / Alliance)
None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.
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?
1,396
1,396 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.
1,396 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).
996 in the last 10 years · low confidence
Phrase hits: 2 · MeSH hits: 0
Who's working on it?
4
Distinct author names in 2 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.
- 01Dohi E1 paper · 2022
Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan.
Papers in Europe PMC - 02Holliday LS1 paper · 2025
Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL 32610, USA.
Papers in Europe PMC - 03Matsui H1 paper · 2022
Department of Neuroscience of Disease, Brain Research Institute, Niigata University, Niigata, Japan.
Papers in Europe PMC - 04Yang X1 paper · 2025
Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL 32610, USA.
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 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.
See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
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 22 · after dedupe 22 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 22 · 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).
Uncertain / not reviewed (22)
- ctis·2025-524635-39-00·Authorised·An Open Label, Single Arm, Phase I/II Clinical Study of Autologous CD4+ T-Cells Edited Ex-Vivo at the CD40LG Locus by CRISPR/Cas9 and IDLV-based vector in Patients with X-linked Hyper IgM Syndrome Type 1 (HIGM1)
skipped — LLM skipped (--skip-llm)
- ctis·2025-523275-27-00·Authorised, recruiting·HELIOS: An Open-Label, Long-Term Study to Investigate the Safety, Tolerability, and Efficacy of DISC-1459 (Bitopertin) in Participants with Erythropoietic Protoporphyria (EPP) or X-Linked Protoporphyria (XLP).
skipped — LLM skipped (--skip-llm)
- ctis·2025-523213-29-00·Authorised·A Phase 1/2, Multicenter, Open-label, Dose Escalation and Expansion Clinical Study to Evaluate the Safety, Tolerability and Preliminary Efficacy of ASP2957 in Male Participants with Invasive Ventilator-dependent X-linked Myotubular Myopathy
skipped — LLM skipped (--skip-llm)
- ctis·2024-519779-24-00·Authorised, ongoing·GFM-VEXAS-MMB: A single-arm phase II with safety run-in multicenter study of momelotinib in patients with VEXAS syndrome with or without associated myelodysplastic syndrome
skipped — LLM skipped (--skip-llm)
- ctis·2024-520407-27-00·Expired·APOLLO: A Randomized, Double-Blind, Placebo-Controlled Study of Bitopertin to Evaluate the Efficacy, Safety, and Tolerability in Participants with
Erythropoietic Protoporphyria (EPP) or X-Linked Protoporphyria (XLP)
skipped — LLM skipped (--skip-llm)
- ctis·2024-516347-41-00·Expired·PAXIS: A randomized, double-blind, placebo-controlled dose-finding phase 2 study (Part 1) followed by an open-label period (Part 2) to assess the efficacy and safety of pacritinib in patients with VEXAS syndrome
skipped — LLM skipped (--skip-llm)
- ctis·2024-512700-18-00·Expired·Long-Term Follow-up of Fabry Disease Subjects who were Treated with ST-920, an AAV2/6 Human Alpha Galactosidase A Gene Therapy
skipped — LLM skipped (--skip-llm)
- ctis·2024-518989-27-01·Cancelled·Treating Leg Symptoms in Women with X-linked Adrenoleukodystrophy: A Key to Improving Sleep and Gait Performance
skipped — LLM skipped (--skip-llm)
- ctis·2023-509390-23-00·Authorised, ongoing·A Multicenter, Open-label, Phase 1/2, Dose-escalation and Subsequent Safety Extension Study of Subcutaneous KK8123 in Adult Patients with X-linked Hypophosphatemia
skipped — LLM skipped (--skip-llm)
- ctis·2023-507994-16-00·Cancelled·A Long-term Follow-up Study to Evaluate the Safety and Efficacy of Retinal Gene Therapy in Subjects with Choroideremia Previously Treated with Adeno-Associated Viral Vector Encoding Rab Escort Protein-1 (AAV2-REP1) and in Subjects with X-Linked Retinitis Pigmentosa Previously Treated with Adeno-Associated Viral Vector Encoding RPGR (AAV8-RPGR) in an Antecedent Study (SOLSTICE)
skipped — LLM skipped (--skip-llm)
- ctis·2024-511181-36-00·11·A Randomized, Controlled, Masked, Multi-center Study Evaluating the Efficacy, Safety, and Tolerability of Two Doses of AGTC-501 Compared to an Untreated Control Group in Male Participants with X-linked Retinitis Pigmentosa
skipped — LLM skipped (--skip-llm)
- ctis·2024-514466-38-00·Expired·A Phase 3, Multicenter, Open-label, Long-term, Extension Study to Evaluate Safety and Tolerability of Oral Dersimelagon (MT-7117) in Subjects with Erythropoietic Protoporphyria (EPP) or X-Linked Protoporphyria (XLP)
skipped — LLM skipped (--skip-llm)
- ctis·2024-512695-34-00·Cancelled·A Phase I/II, Multicenter, Open-Label, Single-Dose, Dose-Ranging Study to Assess the Safety and Tolerability of ST-920, an AAV2/6 Human Alpha Galactosidase A Gene Therapy in Subjects with Fabry Disease.
skipped — LLM skipped (--skip-llm)
- ctis·2024-513124-41-00·Cancelled·Influencing Progression of Airway Disease in Primary Antibody Deficiency
skipped — LLM skipped (--skip-llm)
- ctis·2024-512790-27-00·Cancelled·A phase I/II, non randomized, monocentric open-label study of autologous CD34+ cells transduced with the G1XCGD lentiviral vector in patients with X-linked chronic granulomatous disease
skipped — LLM skipped (--skip-llm)
- ctis·2024-511411-25-00·Expired·Phase 3 Follow-up Study of AAV5-hRKp.RPGR for the Treatment of X-linked Retinitis Pigmentosa Associated with Variants in the RPGR gene
skipped — LLM skipped (--skip-llm)
- ctis·2024-513774-21-00·Expired·AN OPEN-LABEL, MULTICENTER STUDY IN MALE PEDIATRIC PATIENTS WITH CEREBRAL X-LINKED ADRENOLEUKODYSTROPHY (CALD) TO ASSESS THE EFFECTS OF MIN-102 TREATMENT ON DISEASE PROGRESSION PRIOR TO HUMAN STEM CELL TRANSPLANT (HSCT)
skipped — LLM skipped (--skip-llm)
- ctis·2024-512632-30-00·Authorised, ongoing·A prospective, open-label, genotype-match controlled, multicenter clinical trial to investigate the efficacy and safety of intra-amniotic ER004 as a prenatal treatment for male subjects with X-linked hypohidrotic ectodermal dysplasia (XLHED)
skipped — LLM skipped (--skip-llm)
- ctis·2023-504419-34-00·Expired·A three-period multicenter study, with a randomized-withdrawal, double-blinded, placebo-controlled design to evaluate the clinical efficacy, safety and tolerability of MAS825 in patients with monogenic IL-18 driven autoinflammatory diseases, including NLRC4-GOF, XIAP deficiency, or CDC42 mutations.
skipped — LLM skipped (--skip-llm)
- ctis·2024-512637-32-00·Expired·ASPIRO: A Phase 1/2/3, Randomized, Open-Label, Ascending-Dose, Delayed-Treatment Concurrent Control Clinical Study to Evaluate the Safety and Efficacy of AT132, an AAV8-Delivered Gene Therapy in X-Linked Myotubular Myopathy (XLMTM) Patients
skipped — LLM skipped (--skip-llm)
- ctis·2023-506735-15-00·Cancelled·MT-7117-A-302 Study: A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate Efficacy, Safety, and Tolerability of MT-7117 in Adults and Adolescents with Erythropoietic Protoporphyria or X-Linked Protoporphyria
skipped — LLM skipped (--skip-llm)
- ctis·2023-504534-21-00·Cancelled·Open-label extension study with Tadekinig alfa (r-hIL-18BP) to monitor safety and tolerability in patients with IL-18 driven monogenic autoinflammatory conditions: NLRC4 mutation and XIAP deficiency
skipped — LLM skipped (--skip-llm)
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 X-linked parkinsonism-spasticity syndrome — check Associations / patient organisations on that page.
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.
("X-linked parkinsonism-spasticity syndrome" OR "Parkinsonism with spasticity, X-linked, X-linked recessive") OR ("ATP6AP2" OR "ATP6AP2 syndrome" OR "ATP6AP2-related")ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"X-linked parkinsonism-spasticity syndrome" OR "Parkinsonism with spasticity, X-linked, X-linked recessive"
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
Synonyms dropped by stoplist: XPDS
Confidence reasoning
- Preferred label is multi-word and distinctive
- 1 synonym(s) dropped by stoplist (may under-count)
- No label/synonym collisions with other diseases in this corpus
- Publication count (1396) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity
Ingested 2026-07-27T14:40:24.762Z