Heredity and Prophylaxis of Thalassaemia

If both parents are not carriers, all of their children will not be infected.

Generally, if both parents are carriers, they may give birth to children with Thalassaemia. In Hong Kong, it is common to see both parents who are α-Thalassaemia or β-Thalassaemia minor carriers, giving birth to children with α-Thalassaemia or β-Thalassaemia major.

If one parent is a carrier and the other is not, each child will have a 50% chance of becoming a Thalassaemia carrier (Thal-minor).

Now, it is simple to get tested to see if you might be a carrier of either types of Thalassaemia through an easy blood test. If both you and your partner are β-Thalassaemia minor carriers, each of your children will have 25% of chance to be ‘normal’, 50% of chance of becoming a Thalassaemia carrier, and 25% of chance of becoming a patient with Thalassaemia Major. Since α-Thalassaemia comes with more complex detective genes, you have to take a more detailed genetic analysis in order to know whether you have a chance in passing that defective gene to your children.

If both parents are carriers of the same type of Thalassaemia, each of their children will have a 25% chance to be ‘normal’, 50% chance of becoming a Thalassaemia carrier, and 25% chance of becoming infected with Thalassaemia Major.

If you already know that both you and your partner are either α-Thalassaemia or β-Thalassaemia carriers, consult your obstetrician regarding prenatal diagnosis. If both parents do not want to bring a child into the world with suffering, doctors are able to terminate a pregnancy at the early stages. Doing an abortion at the early stages, guarantees a better health for the woman.