Sea in the Blood Thalassaemia - meaning ' sea in the blood ' - is the name given to a once mysterious disease which was found in Mediterranean countries. More recently it was shown to be one of the most common genetic diseases in the world. Today, as a result of the applica-, tion of the most advanced methods of biology, more is known about this form of anaemia than any other disease. But this knowledge will not simply affect the sufferers; there is no doubt that its consequences for genetics are widespread and will affect us all. In less than a generation it is likely that many people will face difficult, many think dangerous, choices as a result of the new biology. Robert Reid looks at the work, how it affects people in underdeveloped countries, how it is 'already affecting people in Britain ', and what its wider effects might be.