"I've been having tests for anaemia, and the laboratory has discovered that I carry beta thalassaemia. I've been told that this won't cause me any problems, but my parents and grandparents were born in the UK and, as far as we know, there is no Mediterranean or Middle Eastern ancestry in our family, so how is it possible that I have this condition, which is supposed to affect only people from other parts of the world?"

Dr Fred Kavalier answers your health question:

Beta thalassaemia is a genetic blood disorder that is common is some parts of the world Mediterranean countries, the Middle East, and Asia. It is relatively rare among native "British" people. If you are a carrier of beta thalassaemia, you will have inherited it from one of your parents. So, if your parents are still alive and willing to have blood tests, you might be able to trace which side of the family it has come from. The likelihood is that someone in a previous generation had a partner who was originally from a part of the world where thalassaemia is common. The important point for you is that, if you have children with a partner who is also a carrier of beta thalassaemia, there is a one-in-four chance that a child could inherit the gene from both of you, and this would cause the child to have the serious form of the disease beta thalassaemia major. Before you have children, it is important to find out if your partner is also a carrier. You can find out more from your local Sickle Cell and Thalassaemia Centre, or the UK Thalassaemia Society (www.ukts.org).

Please mail your questions for Dr Fred to health@independent.co.uk. He regrets that he is unable to respond personally to questions.