Frequently Asked Questions

Nothing happens. A carrier will be perfectly healthy, and needs no treatment or medical attention. Carrying a β-thalassaemia gene becomes important only when a carrier marries another carrier. In this case each pregnancy has a 25% chance that the baby will have thalassaemia. So it is important to know whether a couple carries the affected thalassaemia gene, so they can decide how to proceed with planning a family.
In most cases, simple but specific laboratory tests can identify whether a person is a carrier of sickle cell or of any other haemoglobin disorder, as described below.

Laboratory testing for sickle cell, as for other haemoglobinopathies, includes a routine blood test known as a Complete Blood Count (CBC), which involves measuring the level of haemoglobin and other parameters, such as the Mean Corpuscular Volume (MCV), and the Mean Corpuscular Haemoglobin (MCH), both of which may be within normal range in HbS carriers, in contrast to those carrying α- or β-thalassaemia.

Another test that is used to determine the carrier state includes a laboratory process known as haemoglobin electrophoresis, which enables the measurement of the quantity of the major (HbA) and minor (HbA2) components of adult haemoglobin, foetal haemoglobin (HbF) and HbS. In the case of HbS carriers, the HbS fraction will constitute up to 40% of the total haemoglobin. The presence of HbS may also be confirmed in a very simple way in a test tube, referred to as the Solubility Test.

Other ways to diagnose HbS include Isoelectric Focusing (IEF), which is another kind of electrophoresis, High Pressure Liquid Chromatography (HPLC) and Capillary Chromatography, all of which are considered today as methods of reference for screening as well as confirming the diagnosis of full blown haemoglobinopathies.

If the above tests are inconclusive, especially if combinations with other variants or thalassaemias are involved, and do not allow the laboratory scientists to provide a confirmed diagnosis, other more specialised tests are available. These are genetic tests, i.e. tests which examine the genetic material – the DNA of the blood of the individual but also often of other members of the family.

Like other pregnant women, those who carry HbS can become iron deficient and may need extra iron. The anaemia will improve after the baby is born. HbS carrier pregnant women are also more prone to urine infections, as compared to non-carriers or carriers of other haemoglobin disorders.

Like β & α-thalassaemia carriers, a person who carries HbS will always carry it in his/her genes throughout his/her life, and the carrier status cannot be acquired or transmitted through the environment, transfusion or other means by which people become infected. Carriers who have inherited HbS from their parents could pass it on to their children through their genes.

Yes, many adult patients are now married and have become parents or even grand-parents (in some countries). The possibilities of passing on their genes to their children are as follows: Children from parents of whom one of them has β-thalassaemia major/intermedia and the other has fully functional β-globin genes will all be carriers of β-thalassaemia (in which case, they will be free of thalassaemia disease, and will not need any medical treatment or monitoring). Children from parents of whom one is a β-thalassaemia carrier and the other is a patient with β-thalassaemia major/intermedia will have a one-in-two chance (50%), to be carriers of β-thalassaemia (and be free of the disease) and a one-in-two (50%) chance to be patients with β-thalassaemia major/intermedia. When both parents are patients with β-thalassaemia major/intermedia, all children will also be patients with β-thalassaemia major/intermedia.
Carriers may be suitable blood donors if their haemoglobin level meets the national inclusion criteria for donating blood.
A person who is born carrying β-thalassaemia will always carry it in his/her genes throughout life.
A carrier should let their brother or sister know about their condition and advise them to also have a blood test for Hb disorders.
Carriers should encourage their partners to have a special blood test which ideally should be done before they start a pregnancy. In this case, partners who are both carriers should see a genetic counsellor or a physician to obtain further information and take the time to consider and decide what is best for them.
Thalassaemia major is treated with regular blood transfusions and iron chelation with one or a combination of two of the three available drugs: desferioxamine (Desferal), desferasirox (Exjade), deferiprone (Ferriprox, L1).
The best blood transfusion regimen should be 10-15 ml of concentrated, well screened, filtered, washed (for special cases) and extensively cross-matched red cells provided over 3-4 hours every 2-5 weeks.
The level of haemoglobin (Hb) reflects the level of anaemia. Effective blood transfusion therapy should maintain Hb levels between 9.00-10.5 g/dl at all times.
Red blood cells are the only component of blood affected in thalassaemia major. So, it is unnecessary to provide patients with whole blood, which contains other components (plasma, leukocytes, thrombocytes). Filters are used to remove leukocytes completely from red cells. This offers considerable advantages because leukocytes are associated with certain unwanted reactions and with the transfer of infectious agents such as cytomegalovirus (CMV) and Yersinia, which can lead to serious infections. Washing RBCs with saline may remove plasma proteins associated with the development of severe allergic reactions. Incompatibility with major ABO and Rhesus blood groups may lead to very serious haemolytic reactions. Incompatibility with other blood group systems may lead to production of proteins or antibodies that may start attacking the transfused red cells, destroying them and so making the blood transfusion therapy ineffective.
Positive effects are: combats anaemia, minimises bone marrow hyperactivity, prevents or delays spleen enlargement, results in normal growth and physical activity. The negative effects are the following: Transfused red cells have a defined survival in the circulation, after which they break down and new cells are required through another transfusion. When these cells breakdown iron deposits in the cells, and tissues of the body, which is harmful and if not timely and appropriately removed causes many and serious medical complications.
Excess iron is very harmful, causing serious heart, endocrine and liver complications, which can even be fatal. Excess iron is removed in a process known as iron chelation using special drugs (iron chelators). Today, these are desferioxamine (Desferal), desferasirox (Exjade), deferiprone (Ferriprox, L1).
Provided that patients are compliant with currently recommended treatment, they can live a near normal, happy and full-filling life. The only advice is to avoid food rich in iron and refrain or take special precautions when travelling to high altitudes. Special diets or restrictions on physical exercise may be recommended by a doctor when patients have medical problems such as diabetes or heart complications.
Excess iron is very harmful, causing serious heart, endocrine and liver complications, which can even be fatal. Excess iron is removed in a process known as iron chelation using special drugs (iron chelators). Today, these are desferioxamine (Desferal), desferasirox (Exjade), deferiprone (Ferriprox, L1).
Removing the spleen (splenectomy) deprives the body of an important component that helps it fight infections. Severe infections is therefore, the most important threat after splenectomy. Antibiotics and vaccinations are the best ways to treat infections related to splenectomy.
Patients with thalassaemia graduate from high schools, go to university, have careers and have a family. If patients comply with treatment and do their best to stay healthy, they can lead a near normal life.
At the moment bone marrow transplantation is the only cure, although research in gene therapy has produced in recent years great optimism and expectations.
Bone marrow transplantation is most successful when the donor matches fully the patient’s special blood characteristics known as HLA antigens. This happens when very close relatives (sisters and brothers) offer their bone marrow for transplantation and when the patient is fairly young and well treated. Bone marrow transplantation is more risky when the patient has: enlarged liver, liver damage or poor control of iron overload. When a fully matched sibling is the donor and the patient is free of the above risks, bone marrow transplantation can have a very successful outcome.
To increase the number of γ-chains which will couple with the free excess α-chains, producing more foetal haemoglobin (α2γ2). In this way a form of the haemoglobin HbF is increased in the blood and which has the capacity to carry oxygen around the tissues, while at the same time reduces the toxic effects of the free α-chains. The drugs that are used for this purpose are called HbF inducers and include: butyric acid, hydroxyurea and erythropoetin, used alone or in combination.