Contributor: Michael J. Paxhia and Sharon Fekrat
A hemoglobinopathy is a genetic disorder of hemogloblin synthesis. The amino acid composition of the polypeptide chains of the globin fraction of hemoglobin is altered. In some instances a substitution of a single amino acid occurs, usually in the a or b chains. The potential number of different hemoglobinopathies is enormous and more than 500 hemoglobins have been characterized. Many hemoglobinopathies are rare and not of ophthalmologic importance. Important hemoglobinopathies include sickle cell disease, hemoglobin C disease, sickle cell hemoglobin C disease and thalassemia.