Rare diseases · Sign or symptom
Decreased total leukocyte count
Decreased blood leukocyte number
HP:0001882
What it means
An abnormal decreased number of leukocytes in the blood.
Rare diseases that can present with this51
Common30–79%
21- Acute erythroid leukemia
- Acute promyelocytic leukemia
- Avian influenza
- Babesiosis
- Brucellosis
- Congenital progressive bone marrow failure-B-cell immunodeficiency-skeletal dysplasia syndrome
- Cytomegalovirus disease in patients with impaired cell mediated immunity deemed at risk
- Ebola hemorrhagic fever
- Gaucher disease
- Griscelli syndrome
- Hepatoportal sclerosis
- Insulin-resistance syndrome type B
- Kikuchi-Fujimoto disease
- Lujo hemorrhagic fever
- Lysinuric protein intolerance
- Mucopolysaccharidosis-like syndrome with congenital heart defects and hematopoietic disorders
- Pediatric systemic lupus erythematosus
- Sarcoidosis
- Systemic lupus erythematosus
- Tick-borne encephalitis
- Vitamin B12-unresponsive methylmalonic acidemia
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 1 disease 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
Also called: Leukopenia · Low white blood cell count
Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.
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.