Traits

Traits linked to PNP

purine nucleoside phosphorylase

The Human Phenotype Ontology links 58 traits to PNP, by body system: features seen in people with one of the gene's rare conditions.

PNP

Abnormality of the nervous system

Trait	How often it is seen
Ataxia	Always
Delayed motor skills	Always
Abnormality of the nervous system	Often (30–79%)
Abnormal central motor function	Sometimes (5–29%)
Behavioral abnormality	Sometimes (5–29%)
Cerebral palsy	Sometimes (5–29%)
Global developmental delay	Sometimes (5–29%)
Intellectual disability	Sometimes (5–29%)
More active than typical	Sometimes (5–29%)
Motor delay	Not recorded
Tetraparesis	Not recorded
Tremor	Not recorded

Abnormality of the immune system

Trait	How often it is seen
Autoimmunity	Often (30–79%)
Humoral immunodeficiency	Often (30–79%)
Recurrent infections	Often (30–79%)
Recurrent respiratory infections	Often (30–79%)
Severe combined immunodeficiency	Often (30–79%)
Systemic lupus erythematosus	Rarely (1–4%)
Pneumonia	Not recorded
Recurrent bacterial infections	Not recorded
Recurrent chest infections	Not recorded
Recurrent opportunistic infections	Not recorded
Recurrent viral infections	Not recorded

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Decreased blood lymphocyte number	Always
Pure red cell aplasia	Always
Abnormal T cell morphology	Very often (80–99%)
Autoimmune hemolytic anemia	Often (30–79%)
Low T cell count	Sometimes (5–29%)
Autoimmune thrombocytopenia	Rarely (1–4%)
Autoimmune neutropenia	Not recorded
Cancer of lymphatic system	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Involuntary muscle stiffness, contraction, or spasm	Sometimes (5–29%)
Low muscle tone	Sometimes (5–29%)
Spastic paraparesis	Sometimes (5–29%)
Spasticity and rigidity of muscles	Sometimes (5–29%)
Generalized decreased muscle tone	Not recorded
Spastic diplegia	Not recorded

Laboratory abnormality

Trait	How often it is seen
Decreased urinary urate	Always
Elevated urinary guanosine level	Always
Elevated urinary inosine level	Always
Low blood uric acid levels	Always
Increased circulating guanosine concentration	Not recorded
Increased circulating inosine concentration	Not recorded

Abnormality of the cardiovascular system

Trait	How often it is seen
Stroke	Rarely (1–4%)
Cerebral vasculitis	Not recorded
Increased spleen size	Not recorded
Small lymph nodes	Not recorded

Abnormal cellular phenotype

Trait	How often it is seen
Decreased mitogen-induced T-cell proliferation	Always
Abnormality of B cell physiology	Not recorded
Impaired T cell function	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Recurrent colds	Not recorded
Sinus disease	Not recorded

Abnormality of the ear

Trait	How often it is seen
Sensorineural hearing impairment	Rarely (1–4%)
Middle ear infection	Not recorded

Abnormal tissue mass

Trait	How often it is seen
Abnormal tissue mass	Sometimes (5–29%)

Abnormality of the digestive system

Trait	How often it is seen
Unusual gastrointestinal infection	Often (30–79%)

Abnormality of the genitourinary system

Trait	How often it is seen
Frequent urinary tract infections	Not recorded

Growth abnormality

Trait	How often it is seen
Faltering weight	Not recorded

How often is among people with one of the gene's conditions, the most often across them, as the Human Phenotype Ontology records it. These pages describe traits and the research behind them; they are not a diagnosis, and a doctor or genetic counsellor is the person to ask about symptoms.

Where this comes from

The Human Phenotype Ontology, release 2026-09-01: the traits linked to PNP and how often each is seen. Find out more at hpo.jax.org.

One test. A lifetime of answers.

From $449Free shipping · Results in 6–8 weeks

Get my Genome Test