Glanzmann thrombasthenia 1
Findings
No curated finding names Glanzmann thrombasthenia 1 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A plalelet type bleeding disorder characterized by lifelong mucocutaneous bleeding, markedly impaired platelet aggregation, and absent or severely reduced clot retraction due to failure of the αIIbβ3 integrin complex to bind fibrinogen. Platelets appear normal in number and morphology, but aggregation responses to physiologic agonists (including ADP, collagen, epinephrine, and thrombin) are severely decreased or absent, while ristocetin‑induced agglutination remains normal. Biallelic loss‑of‑function ITGA2B variants reduce or abolish surface expression of the αIIbβ3 receptor, preventing fibrinogen‑mediated platelet bridging and producing the classic Glanzmann thrombasthenia phenotype.
Definition from the Mondo Disease Ontology (MONDO:0031332), read 2026-09-29. CC BY 4.0.
- Onset and course
- Neonatal onset
HPO, annotations 2026-09-02
Features
11 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.
- Decreased platelet glycoprotein IIb-IIIaHPOHP:0001975
- 12 of 12 reported patients
- EcchymosisHPOHP:0031364
- 1 of 1 reported patient
- EpistaxisHPOHP:0000421
- 1 of 1 reported patient
- Excessive bleeding from superficial cutsHPOHP:0030138
- 1 of 1 reported patient
- Impaired ADP-induced platelet aggregationHPOHP:0004866
- 13 of 13 reported patients
- Impaired clot retractionHPO
Genes
2 genes
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.
- ITGA2BHGNC:6138
- Definitive · Ambry Genetics · Autosomal recessive · 2018
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2021
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
- ITGB3HGNC:6156
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
- A kind of
Other names
8 names
Resolves to: Glanzmann thrombasthenia 1
- Also called
- BDPLT2bleeding disorder, platelet-type, 2deficiency of GP 2B 3A complexITGA2B-related Glanzmann thrombastheniaPlatelet glycoprotein 2B 3A deficiencyplatelet glycoprotein IIb-IIIa deficiencythrombastheniathrombasthenia of Glanzmann and Naegeli