National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Purine nucleoside phosphorylase deficiency


Other Names:
PNP deficiency
Categories:
Purine nucleoside phosphorylase (PNP) deficiency is a disorder of the immune system (primary immunodeficiency) characterized by recurrent infections, neurologic symptoms, and autoimmune disorders. PNP deficiency causes a shortage of white blood cells, called T-cells, that help fight infection. Some people with this condition develop neurologic symptoms, such as stiff or rigid muscles (spasticity), uncoordinated movements (ataxia), developmental delay, and intellectual disability.[1][2][3] In addition, PNP deficiency is associated with an increased risk to develop autoimmune disorders, such as autoimmune hemolytic anemia, idiopathic thrombocytopenic purpura (ITP), autoimmune neutropenia, thyroiditis, and lupus.[1][3] PNP deficiency is caused by mutations in the PNP gene and is inherited in an autosomal recessive manner. Treatment with bone marrow transplantation can improve the immune system problems associated with this condition, but does not improve the neurologic symptoms.[1][2][3]
Last updated: 10/5/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal T cell morphology 0002843
Decreased urinary urate 0011935
30%-79% of people have these symptoms
Autoimmune hemolytic anemia 0001890
Humoral immunodeficiency 0005363
Hypouricemia
Low blood uric acid levels
0003537
Recurrent respiratory infections
Frequent respiratory infections
Multiple respiratory infections
respiratory infections, recurrent
Susceptibility to respiratory infections
[ more ] 		0002205
Severe combined immunodeficiency 0004430
Unusual gastrointestinal infection 0032166
5%-29% of people have these symptoms
Ataxia 0001251
Behavioral abnormality
Behavioral changes
Behavioral disorders
Behavioral disturbances
Behavioral problems
Behavioral/psychiatric abnormalities
Behavioural/Psychiatric abnormality
Psychiatric disorders
Psychiatric disturbances
[ more ] 		0000708
Cerebral palsy 0100021
Decreased proportion of CD3-positive T cells 0045080
Global developmental delay 0001263
Hyperactivity
More active than typical
0000752
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Muscular hypotonia
Low or weak muscle tone
0001252
Neoplasm 0002664
Spastic paraparesis 0002313
1%-4% of people have these symptoms
Autoimmune thrombocytopenia 0001973
Sensorineural hearing impairment 0000407
Stroke 0001297
Systemic lupus erythematosus 0002725
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
  • Orphanet lists international laboratories offering diagnostic testing for this condition.
If left untreated, PNP deficiency usually causes death during the first or second decade of life due to recurrent infections.[4] Treatment with a bone marrow transplant may cure the immune system problems and improve the prognosis. However, bone marrow transplantation does not correct the neurologic symptoms associated with this condition.[1]
Last updated: 10/5/2016

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnosis includes aplastic anemias, SCID, severe combined immunodeficiency due to adenosine deaminase deficiency, ataxia-telangiectasia, and viral meningoencephalitis.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • Orphanet lists European clinical trials, research studies, and patient registries enrolling people with this condition. 

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Purine nucleoside phosphorylase deficiency. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • What is the life expectancy for someone with purine nucleoside phosphorylase deficiency? See answer


  1. Knutsen AP. Purine Nucleoside Phosphorylase Deficiency. Medscape. Sep 22, 2015; http://emedicine.medscape.com/article/887823. Accessed 10/5/2016.
  2. purine nucleoside phosphorylase deficiency. Genetics Home Reference. April 2012; https://ghr.nlm.nih.gov/condition/purine-nucleoside-phosphorylase-deficiency. Accessed 10/5/2016.
  3. Pr Eyal Grunebaum. Purine nucleoside phosphorylase deficiency. Orphanet. April 2015; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=760. Accessed 10/5/2016.
  4. CF Classen, AS Schulz, M Sigl-Kraetzig, GF Hoffmann, HA Simmonds, L Fairbanks, KM Debatin, W Friedrich. Successful HLA-identical bone marrow transplantation in a patient with PNP deficiency using busulfan and fludarabine for conditioning. Bone Marrow Transplantation. July 1, 2001; 28:93-96. http://www.nature.com/bmt/journal/v28/n1/full/1703100a.html. Accessed 10/5/2016.