thrombocythemia 1
Findings
No curated finding names thrombocythemia 1 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Any familial thrombocytosis caused by a variation in the THPO gene, which encodes thrombopoietin, characterized by sustained thrombocythemia from excessive thrombopoietin signaling that ranges from asymptomatic thrombocytosis to thrombotic or hemorrhagic episodes, with rare progression to leukemic transformation.
Definition from the Mondo Disease Ontology (MONDO:0008554), 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
- 3 of 3 reported patients
- Impaired collagen-induced platelet aggregationHPOHP:0008320
- 3 of 3 reported patients
- Impaired epinephrine-induced platelet aggregationHPOHP:0008148
- 3 of 3 reported patients
- ThrombocytosisHPOHP:0001894
- 9 of 9 reported patients
- SplenomegalyHPOHP:0001744
- 1 of 5 reported patients
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.
- THPOHGNC:11795
- Definitive · ClinGen · Autosomal dominant · 2024
- Strong · Genomics England PanelApp · Autosomal dominant · 2020
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2021
- Strong · PanelApp Australia · Autosomal dominant · 2025
- Moderate · Ambry Genetics · Autosomal dominant · 2016
- SH2B3HGNC:29605
- No Known Disease Relationship · Labcorp Genetics (formerly Invitae) · Unknown · 2017
Where it sits
Other names
2 names
Resolves to: thrombocythemia 1
- Also called
- THCYT1THPO-related thrombocythemia