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Blood and immune system diseases

Paroxysmal nocturnal hemoglobinuria (PNH)

An acquired blood disease in which red blood cells break down too early. The urine may be dark. Anemia and a risk of blood clots are seen.

Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source

Orphanet has a guideline for emergency doctors for this disease (language: French, Polish, German, English, Spanish, Italian, Portuguese). See on Orphanet

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Blood and immune system diseases” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

A gene change occurs later in life in a stem cell in the bone marrow. The blood cells that come from this cell lack protective proteins on their surface. A part of the immune system, called complement, breaks these cells down. The bone marrow also often cannot make enough blood cells.

Which symptoms can occur?

The disease can occur at any age; it is usually noticed in young adulthood. Symptoms vary greatly from person to person. Infection or tiredness can trigger attacks.

  • Tiredness, weakness and paleness (common)
  • Dark urine, often in the morning
  • Shortness of breath and fast heartbeat
  • Blood clots in the veins, especially in the veins of the abdomen (sometimes)
  • Belly pain and difficulty swallowing
  • Frequent infections and easy bleeding (if the bone marrow is weak)

How is it diagnosed?

Tests are done to show that red cells are breaking down in the blood. The main diagnostic test is a blood test called flow cytometry. This test counts the blood cells that lack the surface proteins.

Treatment and care

There are approved treatments specific to the disease. These treatments block the complement system and reduce the breakdown of cells. A meningitis vaccine is needed before these treatments. Blood transfusions, treatment to prevent clots, and iron and folic acid supplements may also be used. The only lasting solution is a bone marrow transplant; it is considered in severe cases. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

PNH is not inherited. The gene change happens during life, only in some cells in the bone marrow. For this reason, it is not passed on to children. In a very rare inflammatory form, an inherited tendency plays a role. In this case, genetic counselling may be helpful.

Source: MedlinePlus Genetics: Paroxysmal nocturnal hemoglobinuria · NORD: Paroxysmal Nocturnal Hemoglobinuria

Key facts

How common is it?
Prevalence: 1-9 per 100 000 (Europe)
How is it inherited?
Not inherited
When does it usually start?
Any age
Gene(s) involved
PIGA

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

We could not find a patient association specific to this disease.

For all rare diseases: Nadir Hastalıklar Federasyonu

Support and help

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about PNH

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

Questions you can ask your doctor

  • Could this trial be suitable for us?
  • If we take part, how would current treatment and check-ups be affected?
  • Where does the trial take place, and how are travel and accommodation handled?
  • What happens if we want to leave the trial?

ClinicalTrials.gov lists 44 active interventional studies for this disease. 19 are recruiting now; 6 have sites in Türkiye. Last checked: October 7, 2026.

Selected records (studies with a site in Türkiye first):

See all studies on ClinicalTrials.gov · Joining clinical trials

Blood and immune system diseases: other news

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:447 · ICD-11 3A21.0

Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.

The information on these pages is for general information only and does not replace medical advice. Talk to your doctor about diagnosis and treatment decisions. In an emergency in Türkiye, call 112.

Every update is based on an open source and labeled with its level of evidence. No advertising and no drug brand names. Our scientific principles

This page was translated from Turkish by the Doktorclub editorial team.