gray platelet syndrome
Findings
No curated finding names gray platelet syndrome yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare inherited bleeding disorder caused by a variation in the NBEAL2 gene, characterized by macrothrombocytopenia, myelofibrosis, splenomegaly and typical gray appearance of platelets on Wright stained peripheral blood smear.
Definition from the Mondo Disease Ontology (MONDO:0007686), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
HPO, annotations 2026-09-02
Features
9 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.
- Abnormal bleedingHPOHP:0001892
- Very frequent (80% to 99% of cases)
- Abnormality of thrombocytesHPOHP:0001872
- Very frequent (80% to 99% of cases)
- Bruising susceptibilityHPOHP:0000978
- Very frequent (80% to 99% of cases)
- ThrombocytopeniaHPOHP:0001873
- Very frequent (80% to 99% of cases)
- Abnormality of the menstrual cycleHPOHP:0000140
- Frequent (30% to 79% of cases)
- EpistaxisHPOHP:0000421
- Frequent (30% to 79% of cases)
- Myelodysplasia
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.
- NBEAL2HGNC:31928
- Definitive · ClinGen · Autosomal recessive · 2019
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2023
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal dominant · 2021
Where it sits
Other names
4 names
Resolves to: gray platelet syndrome
- Also called
- Alpha storage pool deficiencyBDPLT4GPSplatelet alpha-granule deficiency