The global problem of genetic disease.
Inherited haemoglobin disorders will undoubtedly cause an increasing health burden in many developing countries. Although much is known about their molecular pathology and the mechanisms for their phenotypic diversity, many important questions remain, not least the role of the environment in modifying the clinical course. Methods for screening these conditions are now well established and inexpensive and it is vital that they are applied to define the magnitude of the problem that will be posed by these conditions in the future. Similarly, they form the basis for widespread screening and counselling programmes directed at developing prenatal diagnosis expertise where this is not available. Answers to some relatively simple questions about the role of the environment could also make a major difference to the management of the haemoglobin disorders. There is a major case for the development of regional networks to apply such technology as has been developed for the control and prevention of the important haemoglobin disorders, particularly in Asian countries.