Inheriting Thalassaemia

Many people originating from the Mediterranean area, the Middle East, Africa or Asia carry thalassaemia. It is common in these regions because it helps to protect carriers against malaria. It is rare in Northern Europeans.

Fig 1: Alpha Thal Carrier and Non Carrier

Inheriting Thalassaemia – Alpha Thal Carrier & Non Carrier

If a couple are tested and only one partner proves to be a carrier then there is no danger to their children. In each pregnancy there is a 1 in 2 chance that the child will carry alpha zero thalassaemia.

FIG 2: Alpha Thal Carrier & Alpha Thal Carrier

Inheriting Thalassaemia – Alpha Thal Carrier & Alpha Thal Carrier

If both partners are carriers then there is a 1 in 4 chance of each pregnancy to produce a child with Alpha Zero thalassaemia major.This is a very serious anaemia that develops in the unborn baby and it can only happen when both parents carry alpha zero thalassaemia.

Genetic counselling is suggested to discuss the several options open for having a healthy family. If after full discussion the couple decide to undertake a pregnancy, the mother can be offered pre-natal testing for the disorder.

FIG 3: Beta Thal Carrier & Beta Thal Carrier

Inheriting Thalassaemia – Beta Thal Carrier & Beta Thal Carrier

If a couple are tested and one partner proves to be a carrier then there is no danger to their children (same as Fig 1). If both partners are carriers there is a 25% chance of each pregnancy to produce a child with beta thalassaemia major.

Genetic counselling is suggested to discuss the several options open for having a healthy family. If after full discussion the couple decide to undertake a pregnancy, the mother can be offered pre-natal testing for the disorder.