What is the difference between thalassaemia major and minor?
To have the overt full-blown condition, one needs to inherit the two defective genes from both parents, therefore making a pair of defective genes. This will produce a clinical condition termed as "major".
This is a very serious condition requiring special treatment for the entire life of the individual. The life expectancy is also considerably reduced.
Thalassaemia minor, on the other hand, means in the particular pair of genes, there is one normal gene and one defective gene. In other words, this person will be known as a carrier of the disease.
Are people with thalassaemia minor better off health-wise?
Most definitely yes. They are much healthier, leading virtually independent lives. It is not unusual for a carrier of the defective gene (i.e. a thalassaemia minor individual) not to be aware of his or her status.
Occasionally, two individual carriers who are partners could find out for the first time about their status when the woman becomes pregnant and when tell-tale findings in routine blood tests lead to specific diagnostic tests.
Who are more at risk of being affected, boys or girls?
Both sexes are affected equally. If the two parents are carriers, the baby will have a one in four chance of ending up with the full-blown condition: that is, thalassaemia major.
What are the chances that the baby will be completely unaffected (if both parents are carriers)?
Again, the chance is one in four. This leaves two in four or a 50% chance of the offspring being a carrier. If such a couple had four children, mathematically, they should expect one completely healthy child, two children who would be relatively healthy but carrying the beta-thalassaemia gene, and one sick child with the condition thalassaemia major. Of course, it does not work that way in real life. They could end up with four completely healthy children, four sick children or any mix.
What are the prospects for the thalassaemia major child?
This is a difficult condition to control and treatment is lifelong. In years gone by, these children were lucky to get to the age of ten. Things have improved markedly in the last three decades or so. The mainstay for the majority remains repeated blood transfusion. With this, thalassaemia major patients commonly make it to their twenties.
What is the biggest problem with frequent blood transfusion?
Infection risks in modem blood transfusion have been severely minimized but not eliminated altogether.
However, the main problem in this condition is the iron overload which is inevitable with repeated transfusions. Excess iron is deposited in major vital organs - including the heart, liver and pancreas - slowly damaging them.
Eventual failure of these organs, especially the heart, leads to death.
Is there anything that can be done to curb the iron overload?
There are various forms of medication used to combat this, so far with mixed success.
Are there any other forms of treatment?
To circumvent blood transfusion, bone marrow transplants have been used, occasionally (but not always) with success. The best chance is produced by the availability of a matching donor, especially if it is a sibling. Not all siblings will match.
Is gene therapy for thalassaemia available?
Research is still going on into the possibility of gene replacement therapy. This, if cracked, will be the fail-safe magic solution to this and many other genetic conditions. Indications are that this is still some way off.