Rare diseases · Sign or symptom
Thrombocytopenia
Low platelet count
HP:0001873
What it means
A reduction in the number of circulating thrombocytes.
Thrombocytopenia can be divided into three major causes; 1) low production of platelets in the bone marrow; 2) intravascular breakdown of thrombocytes; and 3) increased turnover of platelets in spleen or liver (extravascular).
Rare diseases that can present with this190
Very common80–99%
38- 21q22.11q22.12microdeletion syndrome
- Acute myelomonocytic leukemia
- Alpha-thalassemia-myelodysplastic syndrome
- Atypical hemolytic uremic syndrome
- Autosomal dominant macrothrombocytopenia
- Beta-thalassemia-X-linked thrombocytopenia syndrome
- Congenital amegakaryocytic thrombocytopenia
- Crimean-Congo hemorrhagic fever
- DIAPH1-related sensorineural hearing loss-thrombocytopenia syndrome
- Drug-induced lupus erythematosus
- Dyskeratosis congenita
- Familial hemophagocytic lymphohistiocytosis
- Fanconi anemia
- Fetal parvovirus syndrome
- GATA2 deficiency spectrum
- Gray platelet syndrome
- Hoyeraal-Hreidarsson syndrome
- Immune-mediated thrombotic thrombocytopenic purpura
- Immune thrombocytopenia
- Infection-related hemolytic uremic syndrome
- Jacobsen syndrome
- Kasabach-Merritt phenomenon
- Lujo hemorrhagic fever
- Macrophage activation syndrome
- Mucopolysaccharidosis-like syndrome with congenital heart defects and hematopoietic disorders
- Multifocal infantile hemangioma with extracutenous involvement
- Multifocal lymphangioendotheliomatosis-thrombocytopenia syndrome
- Nijmegen breakage syndrome
- Relapsing fever
- SLC35A1-CDG
- TAFRO syndrome
- Thrombocytopenia-absent radius syndrome
- Thrombotic thrombocytopenic purpura
- Toxic epidermal necrolysis
- Transaldolase deficiency
- Von Voss-Cherstvoy syndrome
- Wilson disease
- Wiskott-Aldrich syndrome
Common30–79%
41- 21q deletion syndrome
- Acquired hemophagocytic lymphohistiocytosis associated with malignant disease
- Acquired purpura fulminans
- Acute liver failure
- Acute promyelocytic leukemia
- Acute radiation syndrome
- Acyl-CoA dehydrogenase 9 deficiency
- ALG8-CDG
- Atypical Gaucher disease due to saposin C deficiency
- Avian influenza
- Babesiosis
- Beemer-Ertbruggen syndrome
- Boutonneuse fever
- Cernunnos-XLF deficiency
- Chronic myeloid leukemia
- Chronic neurovisceral acid sphingomyelinase deficiency
- Chronic visceral acid sphingomyelinase deficiency
- COG4-CDG
- Congenital enterovirus infection
- Congenital progressive bone marrow failure-B-cell immunodeficiency-skeletal dysplasia syndrome
- Congenital rubella syndrome
- Congenital syphilis
- Cytomegalovirus disease in patients with impaired cell mediated immunity deemed at risk
- Down syndrome
- Fetal cytomegalovirus syndrome
- Fetal Gaucher disease
- Gaucher disease
- Gaucher disease-ophthalmoplegia-cardiovascular calcification syndrome
- Gaucher disease type 1
- Gaucher disease type 2
- Gaucher disease type 3
- Griscelli syndrome
- Hemophagocytic syndrome associated with an infection
- Hemorrhagic fever-renal syndrome
- Kaposiform hemangioendothelioma
- Lathosterolosis
- Leptospirosis
- Lysinuric protein intolerance
- Malaria
- Maternal uniparental disomy of chromosome 6 syndrome
- Methylmalonic acidemia with homocystinuria, type cblC
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions, and Orphanet separately records 2 diseases where this sign is specifically absent. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.