Health condition
Alpha thalassaemia explained
Alpha thalassaemia comes from losing one to four copies of the alpha-globin genes: one or two lost copies cause a harmless trait often mistaken for iron deficiency; three cause HbH disease; four are incompatible with life.
Why trust this guide
- 01
Editorial team
Written by our editorial team from the UK sources listed on each page.
- 02
Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
- 03
Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
Which gene and test confirm it, who should be tested in the family, and which specialist to see.
-
Everyone carries four alpha-globin genes (two HBA1, two HBA2); severity tracks the number lost
-
One or two deletions: alpha thalassaemia trait - mild microcytosis, normal life, no treatment
-
Three deletions: HbH disease - moderate anaemia, splenomegaly, haemolysis with oxidant stress and iron loading over time
-
Trait matters most for family planning: two carriers of the two-gene-in-cis pattern risk a pregnancy with Bart's hydrops
Understanding the condition
What it is and what happens next.
What causes it, how it is confirmed, and the testing and specialist routes available in the UK.
What it is and how it presents
The commonest consequence of alpha thalassaemia is a lifetime of being prescribed unnecessary iron: trait produces small red cells and a borderline haemoglobin that mimics iron deficiency on a standard blood count. The distinction matters - iron does not help and can accumulate. How the missing genes are arranged matters too: two deletions on the same chromosome (common in South-East Asian ancestry) create reproductive risk that two deletions on opposite chromosomes do not.
Testing, surveillance and specialist care
Diagnosis needs DNA analysis, since routine haemoglobin electrophoresis is often normal in trait; ferritin first to exclude iron deficiency, then alpha-globin genotyping settles it. A haematologist can interpret the genotype for family planning - with partner testing and counselling where both prospective parents carry relevant patterns - and HbH disease earns ongoing specialist review. NHS clinical genetics services carry some of the longest waits in the health service, often many months for a first appointment, whereas private genetic testing and a specialist review can typically be arranged within around two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a haematologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any emergency symptoms.
Frequently asked
Common questions about Alpha thalassaemia explained.
Quick, plain-English answers to what people ask us most.
-
What is alpha thalassaemia?
Alpha thalassaemia is an inherited blood disorder affecting the production of alpha globin chains, a component of haemoglobin, resulting in a range of severity from no symptoms to significant anaemia depending on how many gene copies are affected.
-
What causes alpha thalassaemia?
It is caused by deletions or mutations in the genes responsible for producing alpha globin chains, with severity depending on how many of the four relevant gene copies are missing or altered.
-
What are the symptoms of alpha thalassaemia?
Symptoms range from none at all (with one affected gene) to mild anaemia, fatigue, and pale skin (with two affected genes), through to severe anaemia requiring lifelong blood transfusions in the most severe forms.
-
Is alpha thalassaemia dangerous?
This depends heavily on severity: milder forms cause little to no health impact, while the most severe form (haemoglobin Bart's) is usually incompatible with life, and other significant forms require ongoing medical management.
-
Is alpha thalassaemia genetic?
Yes, it is an inherited condition, with the pattern and severity depending on how many altered gene copies are inherited from each parent, who may themselves be unaffected carriers.
-
Can alpha thalassaemia be cured?
Milder forms don't need curative treatment, while more severe forms causing significant anaemia may require regular blood transfusions, and in some cases, stem cell transplant can offer a potential cure.
-
How is alpha thalassaemia treated?
Treatment depends on severity, ranging from no treatment needed for trait carriers, to regular blood transfusions and iron chelation therapy for those with more significant anaemia.
-
How is alpha thalassaemia diagnosed?
Diagnosis typically involves blood tests showing characteristic red blood cell changes, haemoglobin analysis, and genetic testing to confirm the specific gene deletions involved.
-
Alpha thalassaemia vs beta thalassaemia — what's the difference?
Alpha thalassaemia results from reduced production of alpha globin chains, while beta thalassaemia results from reduced beta globin chain production; both cause anaemia but arise from different genes and can have somewhat different patterns of severity and inheritance.
-
When should I see a doctor about possible alpha thalassaemia, and how quickly can I be seen privately?
See a doctor if you have unexplained anaemia or a relevant family/ethnic background with known risk. NHS haematology referral can take several weeks, while private specialist assessment is often available within about two weeks.