| Citation | His numerous contributions to the genetics of human haemoglobinopathies include determination of the non-coding regions of alpha, beta and gamma-globin mRNA, of the structural alpha-globin gene, and the approach to prenatal diagnosis in fetal blood of sickle-cell disease and beta-thalassaemia and (by endonuclease analysis) of alpha-thalassaemia.
He discovered a DNA polymorphism near the beta-globin gene and used it for linkage analysis of sickling and beta-thalassaemia. This enabled him a) to use amniotic fluid rather than fetal blood for prenatal diagnosis, and b) to study the evolution of sickling in Africa, Europe and Asia. He described gene deletion in Hereditary Persistance of Fetal Haemoglobin and gamma-beta thalassaemia as a cause of haemolytic disease of the new born. He discovered a beta-thalassaemia type arising from non-functional mRNA, determined its cause and corrected it in vitro. He discovered gene deletion as a cause of alpha-thalassaemia and related different severities to the number of deleted genes. He produced evidence for the duplication of the alpha-chain gene and also discovered the triplicated gene. These studies enabled him to relate the rarity of severe alpha-thalassaemia in Mediterraneans and Blacks to the rarity in the two-fold deletion on one chromosome in contrast to what he had found in South-East Asians. He has also demonstrated the amelioration of severity of thalassaemia when alpha and beta thalassaemia interact. |