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ORPHA:79477

Griscelli syndrome type 2

low confidenceSubtype of disorder

Also known as: Griscelli-Pruniéras syndrome type 2 · Hypopigmentation-immunodeficiency with or without neurologic impairment syndrome

Publications

6,511

Trials

0

Interventional, condition-specific

Researchers

1,602

Distinct authors in sample

Gene link

RAB27A

Definitive

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

A rare subtype of Griscelli syndrome characterized by pigmentary dilution in skin and hair with irregular clumps of pigment in hair shafts resulting in silvery hair, in association with increased susceptibility to recurrent infections and immunological abnormalities, in particular impairment of T-cell and natural killer cytotoxic activity eventually leading to hemophagocytic lymphohistiocytosis. Patients may present neurological manifestations related to infiltration of the central nervous system in the context of the hemophagocytic syndrome. The disease is mostly fatal in the first decade of life.

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.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (7)

GS2 · Griscelli syndrome with hemophagocytic syndrome · Griscelli-PruniC)ras syndrome type 2 · Griscelli-Pruni��ras syndrome type 2 · PAID syndrome · hypopigmentation-immunodeficiency with or without neurologic impairment syndrome · partial albinism and immunodeficiency 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.”

5/6 stages with a signal

No specific-condition interventional trial, but broader-category trials exist — discuss eligibility with a clinician.

  1. Gene identifiedPresent

    Definitive — RAB27A

  2. LiteraturePresent

    6,511 matched papers (4,730 in last 10 years) Source

  3. Phenotype characterisedPresent

    31 HPO annotations (e.g. Reduced delayed hypersensitivity; Seizure; Hemophagocytosis) Source

  4. Animal modelPresent

    1 genotype model (Mus musculus) Source

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialPartial

    None under the specific name; 3 for broader category Griscelli syndrome

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 (RAB27A).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

31

Associated phenotypes · MONDO:0011872

  • Reduced delayed hypersensitivity
  • Seizure
  • Hemophagocytosis
  • Accumulation of melanosomes in melanocytes
  • Silver-gray hair

Showing 5 of 31 — open Monarch for the full list.

Animal models (Monarch / Alliance)

1

Model associations linked to this Mondo ID

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?

6,511

6,511 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

6,511 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).

4,730 in the last 10 years · low confidence

Phrase hits: 446 · MeSH hits: 8

Open Europe PMC search

Who's working on it?

1,602

Distinct author names in 200 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.

  1. 01
    Lehmberg K8 papers · 2025

    Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

    Papers in Europe PMC
  2. 02
    Bryceson YT7 papers · 2025

    Centre for Infectious Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden.

    Papers in Europe PMC
  3. 03
    Ehl S6 papers · 2023

    Center for Chronic Immunodeficiency, Medical Center University of Freiburg, Faculty of Medicine, Freiburg, Germany.

    Papers in Europe PMC
  4. 04
    Parvaneh N6 papers · 2023

    Division of Allergy and Clinical Immunology, Department of Pediatrics, Tehran University of Medical Sciences (TUMS), Tehran, Iran.

    Papers in Europe PMC
  5. 05
    de Saint Basile G5 papers · 2017

    Centre d'Etudes des Déficits Immunitaires, Assistance Publique-Hôpitaux de Paris, Hôpital Necker-Enfants Malades, Paris, France.

    Papers in Europe PMC
  6. 06
    Fukuda M5 papers · 2026

    Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.

    Papers in Europe PMC
  7. 07
    Henter JI5 papers · 2024

    Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden.

    Papers in Europe PMC
  8. 08
    Ben-Omran T4 papers · 2024

    Division of Genetic and Genomic Medicine, Sidra Medicine, Doha, Qatar.

    Papers in Europe PMC
  9. 09
    Beutel K4 papers · 2012
    Papers in Europe PMC
  10. 10
    Cugno C4 papers · 2024

    Pediatric Hematology and Oncology Department, Sidra Medicine, Doha, Qatar.

    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). 3 trials are registered for Griscelli syndrome, the broader category — shown separately because they may or may not enrol this specific subtype.

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.

3 interventional trials matched Griscelli syndrome, the broader category — listed below. Those studies are not counted in the condition-specific total.

Broader category: Griscelli syndrome

3

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.

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 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · 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).

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 Griscelli syndrome type 2 — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This 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.

("Griscelli syndrome type 2" OR "Griscelli-Pruniéras syndrome type 2" OR "Hypopigmentation-immunodeficiency with or without neurologic impairment syndrome" OR "Griscelli syndrome with hemophagocytic syndrome" OR "Griscelli-PruniC)ras syndrome type 2" OR "Griscelli-Pruni��ras syndrome type 2" OR "PAID syndrome" OR "partial albinism and immunodeficiency syndrome") OR (MESH:"Griscelli syndrome type 2") OR ("RAB27A" OR "RAB27A syndrome" OR "RAB27A-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Griscelli syndrome type 2

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Griscelli syndrome type 2" OR "Griscelli-Pruniéras syndrome type 2" OR "Hypopigmentation-immunodeficiency with or without neurologic impairment syndrome" OR "Griscelli syndrome with hemophagocytic syndrome" OR "Griscelli-PruniC)ras syndrome type 2" OR "Griscelli-Pruni��ras syndrome type 2" OR "PAID syndrome" OR "partial albinism and immunodeficiency syndrome"

Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"Griscelli syndrome"

Query health: ok — strategies attempted: phrase, mesh; with hits: phrase, mesh

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: GS2

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 (6511) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T02:28:15.820Z