Recent developments in foetal haemoglobin research.

There have been numerous new contributions to the knowledge of foetal haemoglobin over the last few years. It is, therefore, timely to review them together. They throw light on the arrangement on the chromosome of non-alpha chain genes, and on the condition generally known as Hereditary Persistence of Foetal Haemoglobin (HPFH) and have contributed to other aspects of human ontogeny and physiology.