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

Paroxysmal nocturnal hemoglobinuria


Other Names:
PNH; Marchiafava-Micheli disease
Categories:
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disorder that leads to the premature death and impaired production of blood cells. It can occur at any age, but is usually diagnosed in young adulthood. People with PNH have recurring episodes of symptoms due to hemolysis, which may be triggered by stresses on the body such as infections or physical exertion. This results in a deficiency of various types of blood cells and can cause signs and symptoms such as fatigue, weakness, abnormally pale skin (pallor), shortness of breath, and an increased heart rate. People with PNH may also be prone to infections and abnormal blood clotting (thrombosis) or hemorrhage, and are at increased risk of developing leukemia. It is caused by acquired, rather than inherited, mutations in the PIGA gene; the condition is not passed down to children of affected individuals. Sometimes, people who have been treated for aplastic anemia may develop PNH.[1] The treatment of PNH is largely based on symptoms; stem cell transplantation is typically reserved for severe cases of PNH with aplastic anemia or those whose develop leukemia.[2]
Last updated: 1/15/2011

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
Fatigue
Tired
Tiredness
[ more ] 		0012378
Hemolytic anemia 0001878
30%-79% of people have these symptoms
Bone marrow hypocellularity
Bone marrow failure
0005528
Hypercoagulability 0100724
Thromboembolism 0001907
5%-29% of people have these symptoms
Abdominal pain
Pain in stomach
Stomach pain
[ more ] 		0002027
Abnormal bleeding
Bleeding tendency
0001892
Abnormal renal physiology
Abnormal kidney function
Kidney function issue
[ more ] 		0012211
Angina pectoris 0001681
Aplastic anemia 0001915
Cerebral artery stenosis
Narrowing of a cerebral artery
0012492
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty
[ more ] 		0002015
Hemoglobinuria
Hemoglobin in urine
0003641
Hypoplastic anemia 0001908
Muscle weakness
Muscular weakness
0001324
Myelodysplasia 0002863
Myocardial infarction
Heart attack
0001658
Pallor 0000980
Pulmonary arterial hypertension
Increased blood pressure in blood vessels of lungs
0002092
Pulmonary embolism
Blood clot in artery of lung
0002204
Transient ischemic attack
Mini stroke
0002326
1%-4% of people have these symptoms
Acute myeloid leukemia 0004808
Percent of people who have these symptoms is not available through HPO
Arthralgia
Joint pain
0002829
Autosomal dominant inheritance 0000006
Diarrhea
Watery stool
0002014
Dyspnea
Trouble breathing
0002094
Headache
Headaches
0002315
Paroxysmal nocturnal hemoglobinuria 0004818
Somatic mutation 0001428
Urticaria
Hives
0001025
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Last updated: 7/1/2020

The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.

Management Guidelines

  • Orphanet Emergency Guidelines is an article which is expert-authored and peer-reviewed that is intended to guide health care professionals in emergency situations involving this condition.  
  • Project OrphanAnesthesia is a project whose aim is to create peer-reviewed, readily accessible guidelines for patients with rare diseases and for the anesthesiologists caring for them. The project is a collaborative effort of the German Society of Anesthesiology and Intensive Care, Orphanet, the European Society of Pediatric Anesthesia, anesthetists and rare disease experts with the aim to contribute to patient safety.

FDA-Approved Treatments

The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

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 diagnoses include all the other forms of anemia (in particular autoimmune hemolytic anemia) and other causes of deep vein thromboses, according to their clinical presentation.
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

  • ClinicalTrials.gov lists trials that are related to Paroxysmal nocturnal hemoglobinuria. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Organizations Providing General Support

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

  • National Organization for Rare Disorders (NORD) has Disease-Specific Assistance Programs designed to help patients with out-of-pocket costs such as monthly insurance premiums or deductibles. In addition, some programs may provide financial assistance for additional expenses related to a patient's diagnosis such as travel to see a specialist.

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

  • Genetics Home Reference (GHR) contains information on Paroxysmal nocturnal hemoglobinuria. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers. 
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

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. 
    Paroxysmal nocturnal hemoglobinuria 1
    Paroxysmal nocturnal hemoglobinuria 2
  • 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 Paroxysmal nocturnal hemoglobinuria. 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

  • Why does it appear that hemolysis occurs mostly at night? See answer


  1. Paroxysmal nocturnal hemoglobinuria. Genetics Home Reference. May 2007; http://ghr.nlm.nih.gov/condition/paroxysmal-nocturnal-hemoglobinuria. Accessed 1/15/2011.
  2. Emmanuel C Besa and Ulrich Woermann. Paroxysmal Nocturnal Hemoglobinuria. eMedicine. March 27, 2009; http://emedicine.medscape.com/article/207468-overview. Accessed 1/15/2011.