- Hemophagocytosis (HP:0012156): Phagocytosis by macrophages of erythrocytes, leukocytes, platelets, and their precursors in bone marrow and other tissues. Evidence: TAS. Frequency: Obligate (HP:0040280). (ORPHA:158048)
- Splenomegaly (HP:0001744): Abnormal increased size of the spleen. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:158048)
- Pancytopenia (HP:0001876): An abnormal reduction in numbers of all blood cell types (red blood cells, white blood cells, and platelets). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:158048)
- Fever (HP:0001945): Body temperature elevated above the normal range. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:158048)
- Abnormal inflammatory response (HP:0012647): Any anomaly of the inflammatory response, a response to injury or infection characterized by local vasodilation, extravasation of plasma into intercellular spaces and accumulation of white blood cells and macrophages. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:158048)
- Abnormal T cell subset number (HP:0025540): Abnormal increase or decrease of absolute number (either count per volume or percentage of total lymphocytes) of any T cell subpopulation, commonly characterized as CD3+ lymphocytes, in the blood, compared to a reference range for a given sex and age-group. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:158048)
- Abnormal cytokine signaling (HP:0031406): Any abnormality in the series of molecular signals initiated by the binding of a cytokine to a receptor on the surface of a cell, and ending with regulation of a downstream cellular process, e.g. transcription. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:158048)
- Severe viral infection (HP:0031691): An unusually severe viral infection. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:158048)
- Severe infection (HP:0032169): A type of infection that is regarded as a sign of a pathological susceptibility to infection because of unusual severity or intensity of the infection. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:158048)
- Abnormality of the nervous system (HP:0000707): An abnormality of the nervous system. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Thrombocytopenia (HP:0001873): A reduction in the number of circulating thrombocytes. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Decreased total neutrophil count (HP:0001875): Abnormal decrease of absolute number of neutrophils in the blood, per microlitre, compared to a reference range for a given sex and age-group. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Anemia (HP:0001903): A reduction in erythrocytes volume or hemoglobin concentration. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Hypertriglyceridemia (HP:0002155): An abnormal increase in the level of triglycerides in the blood. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Hepatomegaly (HP:0002240): Abnormally increased size of the liver. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Elevated circulating hepatic transaminase concentration (HP:0002910): Elevations of the levels of SGOT and SGPT in the serum. SGOT (serum glutamic oxaloacetic transaminase) and SGPT (serum glutamic pyruvic transaminase) are transaminases primarily found in the liver and heart and are released into the bloodstream as the result of liver or heart damage. SGOT and SGPT are used clinically mainly as markers of liver damage. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Increased circulating ferritin concentration (HP:0003281): Increased concentration of ferritin in the blood circulation. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Disseminated intravascular coagulation (HP:0005521): Disseminated intravascular coagulation is characterized by the widespread activation of coagulation, which results in the intravascular formation of fibrin and ultimately thrombotic occlusion of small and midsize vessels. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Hypofibrinogenemia (HP:0011900): Decreased concentration of fibrinogen in the blood. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Chronic active EBV infection (HP:0032204): Chronic active Epstein-Barr virus (EBV) infection is an uncommon outcome of EBV infection and may present as a waxing and waning or fulminant syndrome. Unlike acute infectious mononucleosis, wherein EBV establishes lifelong infection and survives by maintaining a delicate balance with the host as a latent infection, in chronic active EBV infection the host-virus balance is disturbed. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Abnormal total natural killer cell count (HP:0040089): 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. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:158048)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Hyperproteinemia (HP:0002152): An increased concentration of proteins in the blood. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Cranial nerve paralysis (HP:0006824). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- CSF pleocytosis (HP:0012229): An increased white blood cell count in the cerebrospinal fluid. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Invasive fungal infection (HP:0020101): Fungal infection characterized by invasion of host tissues. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Periventricular white matter hyperintensities (HP:0030891): Areas of brighter than expected signal on magnetic resonance imaging emanating from the cerebral white matter that surrounds the cerebral ventricles. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Nuchal rigidity (HP:0031179): Resistance of the extensor muscles of the neck to being bent forwards (i.e., impaired neck flexion) as a result of muscle spasm of the extensor muscles of the neck. Nuchal rigidity is not a fixed rigidity. Nuchal rigidity has been used as a bedside test for meningism, although its sensitivity for this purpose has been debated. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Severe cytomegalovirus infection (HP:0031692): An unusually severe infection by cytomegalovirus. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Opportunistic bacterial infection (HP:0032260): An infection that is caused by a bacterium that would generally not be able to cause an infection in a host with a normal immune system. Such bacteria take advantage of the opportunity, so to speak, that is provided by a weakened immune system. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:158048)
- Encephalopathy (HP:0001298): Encephalopathy is a term that means brain disease, damage, or malfunction. In general, encephalopathy is manifested by an altered mental state. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:158048)
- Invasive parasitic infection (HP:0031700): A parasitic infection whereby the parasite invades (migrates through) tissues of the infected host. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:158048)
- Unusual Histoplasma capsulatum infection (HP:0032256): An increased susceptibility to Histoplasma capsulatum infections as manifested by a recurrent or severe/invasive infection with Histoplasma capsulatum, or occurring in an unusual anatomical location. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:158048)
These phenotypes are associated with the disease Hemophagocytic syndrome associated with an infection (ORPHA:158048).