What is Southeast Asian (SEA) Alpha Thalassaemia Trait?

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Alpha thalassaemia is a genetic (inherited) blood condition that affects how your body makes haemoglobin—the protein in red blood cells that carries oxygen.

In the Southeast Asian (SEA) type, two of the four alpha-globin genes are missing (deleted). This is sometimes written as:

👉 -- / αα

🩸 What does this mean for you?

Most people with SEA alpha thalassaemia trait:

  • ✅ Feel completely well
  • ✅ Have no symptoms
  • ✅ Live a normal life
  • 🔬 May have mild anaemia (small red blood cells on blood test)

Doctors often notice it because:

  • Your red cells look smaller than usual (microcytosis)
  • But your iron levels are normal (important distinction)

🔬 Why are the red blood cells smaller?

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Haemoglobin is made of protein chains:

  • 2 alpha chains
  • 2 beta chains

In alpha thalassaemia:

  • There aren’t enough alpha chains
  • So haemoglobin is made less efficiently
  • This leads to smaller red blood cells

🧬 How is it inherited?

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Each person has 4 alpha genes (2 from each parent).

If you have SEA trait (--/αα):

  • You are a carrier
  • You can pass this on to your children

Important for family planning:

If your partner is also a carrier:

  • ⚠️ There is a risk of more severe conditions in children, including:
    • HbH disease (moderate anaemia)
    • Hydrops fetalis (very severe, often fatal before birth)

👉 This is why partner testing is often recommended

❗ Do you need treatment?

  • ❌ No treatment is needed
  • ❌ Iron tablets are NOT helpful unless you truly have iron deficiency
  • ✅ Just awareness and correct diagnosis

🧾 Key takeaway

  • SEA alpha thalassaemia trait is benign and common
  • It does not affect your health or lifespan
  • The most important issue is genetic counselling if planning children