bleeding disorder, platelet-type, 21
Findings
No curated finding names bleeding disorder, platelet-type, 21 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
An inherited platelet disorder caused by a variation in the FLI1 gene, an ETS-family transcription factor required for megakaryocyte maturation and formation of platelet alpha- and dense granules. Affected individuals typically exhibit mild to moderate thrombocytopenia, enlarged platelets, and characteristic defects in platelet granules, including absent or markedly reduced dense granules and enlarged or fused alpha-granules, leading to abnormal secretion and impaired aggregation responses. The clinical phenotype ranges from asymptomatic to significant mucocutaneous bleeding, menorrhagia, or perioperative bleeding.
Definition from the Mondo Disease Ontology (MONDO:0054577), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance
HPO, annotations 2026-09-02
Features
5 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Impaired ADP-induced platelet aggregationHPOHP:0004866
- 2 of 2 reported patients
- Increased mean platelet volumeHPOHP:0011877
- 3 of 3 reported patients
- MenorrhagiaHPOHP:0000132
- 1 of 1 reported patient
- ThrombocytopeniaHPOHP:0001873
- 6 of 9 reported patients
- Abnormal bleedingHPOHP:0001892
- 1 of 3 reported patients
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- FLI1HGNC:3749
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2021
- Strong · PanelApp Australia · Autosomal dominant · 2025
- Moderate · Ambry Genetics · Autosomal dominant · 2023
- Moderate · Ambry Genetics · Autosomal dominant · 2025
- Moderate · ClinGen · Autosomal dominant · 2023
- Limited · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2021
Where it sits
Other names
1 name
Resolves to: bleeding disorder, platelet-type, 21
- Also called
- FLI1-related thrombocytopenia