Rare diseases · Sign or symptom
Abnormal total natural killer cell count
HP:0040089
What it means
Abnormal increase or decrease of total natural killer (NK) cells, commonly characterized as CD3-CD19- and CD16+ or CD56+ lymphocytes, in the blood, per microlitre, or altered NK cell phenotype, compared to a reference range for a given sex and age-group, measured ex vivo.
In human peripheral blood, five NK cell subpopulations can be defined on the basis of the relative expression of the markers CD16 and CD56: (1) CD56bright CD16- (50-70% of CD56bright), (2) CD56bright CD16dim (30-50% of CD56bright), (3) CD56dim CD16-, (4) CD56dim CD16bright, and (5) CD56- CD16bright. In healthy individuals, populations (3) and (5) are numerically in the minority.
Rare diseases that can present with this4
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. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Abnormal NK cell count · Abnormal number of natural killer cells · Abnormality of natural killer cell count
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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.