The Molecular Basis of α-Thalassemia: A Model for Understanding Human Molecular Genetics

Down-regulation of alpha-globin synthesis causes alpha-thalassemia with underproduction of fetal (HbF, alpha(2)gamma(2)) and adult (HbA, alpha(2)beta(2)) hemoglobin This article focuses on the human alpha-globin cluster which has been characterized in great depth over the past 30 years In particular the authors describe how the alpha genes are normally switched on during erythropoiesis and switched off as hematopoietic stem cells commit to nonerythroid lineages In addition the principles by which alpha-globin expression may be perturbed by natural mutations that cause alpha-thalassemia are reviewed