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ORPHA:232

Sickle cell anemia

high confidenceDisorder

Also known as: Homozygous hemoglobin S · Homozygous sickle cell anemia SS

Publications

65,856

99.2th percentile

Trials

781

Interventional, condition-specific

Researchers

1,307

Distinct authors in sample

Gene link

HBB

Definitive

Readiness

6/6

Stages with a signal

Clinical definition (Orphanet)

A severe form of sickle cell disease (SCD) characterized by homozygosity for the sickle hemoglobin (HbS) gene and which acutely manifests with severe anemia, susceptibility to severe bacterial infections, and ischemic vasoocclusive accidents (VOA). It is a red cell disease of genetic origin which manifests with hemolytic disease and loss of red cell deformability leading to other occlusive events.

How rare: 1-5 / 10 000 — about one to five people per ten thousand (still uncommon, but less ultra-rare).

Orphanet entry

Cross-references

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

Additional Mondo synonyms (8)

Haemoglobin S disease without crisis · Hb-S/Hb-C disease · Sickle Cell Disease · sickle cell anemia · sickle cell disease · sickle-cell/Hb-C disease without crisis · sickling disorder due to Haemoglobin S · sickling disorder due to Hemoglobin S

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.”

6/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedPresent

    Definitive — HBB

  2. LiteraturePresent

    65,856 matched papers (36,429 in last 10 years) Source

  3. Phenotype characterisedPresent

    56 HPO annotations (e.g. Cardiomegaly; Renal insufficiency; Hematuria) Source

  4. Animal modelPresent

    8 genotype models (Mus musculus) Source

  5. Orphan designationPresent

    15 FDA · 5 EMA designations (15 FDA orphan-indication approvals) — e.g. mitapivat Source

  6. Interventional trialPresent

    781 matched on ClinicalTrials.gov (152 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 (HBB).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

56

Associated phenotypes · MONDO:0011382

  • Cardiomegaly
  • Renal insufficiency
  • Hematuria
  • Hepatomegaly
  • Cholelithiasis

Showing 5 of 56 — open Monarch for the full list.

Animal models (Monarch / Alliance)

8

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)

30

Designations · 15 with FDA orphan-indication approval

  • FDA mitapivatSickle Cell Disease · 2020-11-12 · Not FDA Approved for Orphan Indication
  • FDA RifaximinSickle Cell Disease · 2020-10-28 · Not FDA Approved for Orphan Indication
  • FDA L-citrullineSickle Cell Disease · 2020-10-07 · Not FDA Approved for Orphan Indication
  • FDA apadamtase alfaSickle Cell Disease · 2020-09-28 · Not FDA Approved for Orphan Indication
  • FDA 6-{(1S)-1-[(2-Amino-6-fluoroquinolin-3-yl)oxy]ethyl}-5-(1H-pyrazol-1-yl)pyridin-2(1H)-oneSickle Cell Disease · 2020-09-18 · Not FDA Approved for Orphan Indication
  • FDA Sodium NitriteSickle Cell Disease · 2020-03-25 · Not FDA Approved for Orphan Indication
  • FDA olinciguatSickle Cell Disease · 2018-06-04 · Not FDA Approved for Orphan Indication
  • FDA sirolimusSickle Cell Disease · 2018-03-13 · Not FDA Approved for Orphan Indication

Sources: FDA OOPD · EMA orphan designations

Open Targets candidates

162

Drugs / clinical candidates · MONDO_0011382

CTD chemicals (MyDisease.info)

21 associated chemicals · 94 pathways. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • acetaminophen, codeine drug combination · therapeutic
  • Adrenal Cortex Hormones · therapeutic
  • alpha-Tocopherol · therapeutic
  • Anti-Bacterial Agents · therapeutic
  • Aspartame · therapeutic
  • Baclofen · therapeutic
  • Deferasirox · therapeutic
  • Deferoxamine · therapeutic
  • Folic Acid · therapeutic
  • Hydromorphone · therapeutic
  • Hydroxyurea · therapeutic
  • Meperidine · therapeutic

Pathways: Pyrimidine metabolism; Alanine, aspartate and glutamate metabolism; Drug metabolism - other enzymes; Metabolic pathways; Antifolate resistance; MAPK signaling pathway; cGMP-PKG signaling pathway; Cytokine-cytokine receptor interaction

MyDisease.info · MONDO:0011382

Literature

Is anyone studying this?

65,856

65,856 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.

65,856 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).

36,429 in the last 10 years · high confidence · 99.2th percentile (publications denominator)

Phrase hits: 65,835 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,307

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.

  1. 01
    Arnaud C4 papers · 2026

    Referral Center for Sickle Cell Disease, Department of Pediatrics, Centre Hospitalier Intercommunal, Creteil (CHIC Hospital), Creteil, University Paris XII.

    Papers in Europe PMC
  2. 02
    Bartolucci P4 papers · 2026

    Hôpital Henri Mondor Assistance Publique des Hôpitaux de Paris (AP-HP), Univ Paris Est-Créteil, Créteil, France.

    Papers in Europe PMC
  3. 03
    Connes P4 papers · 2026

    Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Vascular Biology and Red Blood Cell Team, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.

    Papers in Europe PMC
  4. 04
    DeBaun MR4 papers · 2026

    Department of Pediatrics, Vanderbilt-Meharry Center of Excellence in Sickle Cell Disease, Vanderbilt University Medical Center, Nashville, TN.

    Papers in Europe PMC
  5. 05
    Kamdem A4 papers · 2026

    Referral Center for Sickle Cell Disease, Department of Pediatrics, Centre Hospitalier Intercommunal, Creteil (CHIC Hospital), Creteil, University Paris XII.

    Papers in Europe PMC
  6. 06
    Namazzi R4 papers · 2026

    Department of Paediatrics and Child Health, Makerere University School of Medicine, Kampala, Uganda.

    Papers in Europe PMC
  7. 07
    Rodeghier M4 papers · 2026

    Rodeghier Consultants, Chicago, IL.

    Papers in Europe PMC
  8. 08
    Ware RE4 papers · 2026

    Department of Pediatrics, Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.

    Papers in Europe PMC
  9. 09
    Belozertseva E3 papers · 2026

    Pediatric Department, Sickle Cell Disease Referral Center, Centre Hospitalier Intercommunal de Créteil, Créteil, France.

    Papers in Europe PMC
  10. 10
    Bongomin F3 papers · 2026

    Department of Medical Microbiology and Immunology, Faculty of Medicine, Gulu University, Gulu, Uganda.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

781

interventional trials for this specific condition

781 interventional trials matched this specific condition name; 152 currently recruiting in our sample.

Data as of 11 September 2026 · last trial check 28 July 2026

781 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 99.8th percentile).

high confidence · 99.8th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

781 interventional trials matched after quoted-phrase search and title/condition post-filter.

Observational and natural-history studies

298 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

Open the complete matched search on ClinicalTrials.gov

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 21 · after dedupe 21 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 21 · dropped 0 · fetched 2026-07-29

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 (21)

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 Sickle cell anemia — 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.

("Sickle cell anemia" OR "Homozygous hemoglobin S" OR "Homozygous sickle cell anemia SS" OR "Haemoglobin S disease without crisis" OR "Hb-S/Hb-C disease" OR "Sickle Cell Disease" OR "sickle-cell/Hb-C disease without crisis" OR "sickling disorder due to Haemoglobin S" OR "sickling disorder due to Hemoglobin S") OR ("HBB syndrome" OR "HBB-related")

Run this search on Europe PMC

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

"Sickle cell anemia" OR "Homozygous hemoglobin S" OR "Homozygous sickle cell anemia SS" OR "Haemoglobin S disease without crisis" OR "Hb-S/Hb-C disease" OR "Sickle Cell Disease" OR "sickle-cell/Hb-C disease without crisis" OR "sickling disorder due to Haemoglobin S" OR "sickling disorder due to Hemoglobin S"

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: 781 interventional · 298 observational · 5 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 2026-07-26T13:00:10.687Z