Alpha Thalassaemia
What does it mean to carry alpha zero thalassaemia?
Alpha zero thalassaemia is a haemoglobin disorder. Many people of South East Asian or Eastern Mediterranean origin carry alpha zero thalassaemia. 5% of South East Asians (e.g. Hong Kong Chinese) 1-2%. Cypriots and approximately 0.1% of Northern Europeans are carriers.
Haemoglobin disorders are recessively inherited. People who carry one gene for alpha zero thalassaemia (heterozygotes) are popularly called carriers of alpha zero thalassaemia, or said to have alpha zero thalassaemia trait. Alpha thalassaemia trait is suspected on the basis of microcytosis (low MCV and MCH), with a low or normal HbA2 Definitive diagnosis requires DNA analysis, and this has been done in this case.
“You carry alpha zero thalassaemia because you inherited it from one of your parents. Your children may inherit it from you in their turn. You will always carry it. No-one can "catch" it from you, and it will never turn into a serious anaemia”.
Can alpha zero thalassaemia cause any health problems for carriers?
Some carriers have a mild anaemia, but the majority have a haemoglobin in the normal range. Carriers are not ill, are no more likely to become ill than other people, and can do any kind of work.
The most important health problem for carriers is the risk of iatrogenic iron overload. Microcytosis and mild anaemia “can lead to an erroneous diagnosis of iron deficiency anaemia, and years of unnecessary iron medicines. A serum iron or serum ferritin measurement is the only way to make a diagnosis of iron deficiency in a person who carries thalassaemia.
Carriers are as likely to become iron deficient as anyone else, particularly during pregnancy, when iron supplements will be needed.”
Why is it important to know you carry alpha zero thalassaemia?
“Though carrying alpha zero thalassaemia does not affect your own health, carriers can sometimes have a baby with Haemoglobin Barts Hydrops Foetalis a serious inherited anaemia. This can happen only if your partner also carries alpha zero thalassaemia. It is important to know about this risk, because you can avoid it.
If you have a partner and are thinking of having children, tell your partner that you carry alpha zero thalassaemia, and show him or her this leaflet. Ask your partner to have a blood test for haemoglobinopathy. The blood slip should state “request for haemoglobinopathy screen: partner of a known carrier”. He or she can take this leaflet to their family doctor (GP), to help explain why the blood test is needed.
If the test shows your partner does not carry alpha zero thalassaemia, you have no risk of having a child with a serious inherited anaemia. You have a 1 in 2 chance of having a child with alpha zero thalassaemia trait and a 1 in 2 chance of having a child with the usual haemoglobin. If the test shows your partner carries a haemoglobinopathy, you should go together to a specialist thalassaemia counsellor, to be sure about your risk, and to find out how to be sure you have healthy children. Your GP can arrange this.”
Is there anything else you should do now?
“If you have brothers or sisters, or if you already have children, they may also carry alpha zero thalassaemia. Encourage them to have a blood test. Ask them to have a blood test for haemoglobinopathy. The blood slip should state “request for haemoglobinopathy screen: relative of a known carrier”. He or she can take this leaflet to their family doctor (GP), to help explain why the blood test is needed.
If one or more of your relatives is in fact a carrier, they should make sure that their partner has a test before they have children.”
