Systemically, symptoms include painful crises of abdominal and musculoskeletal discomfort. Hemoglobinopathies are among the more commonly inherited diseases in humans.
Hemoglobinopathies result when there is altered structure, function or production of hemoglobin.
Hemoglobin is the principle protein of the erythrocyte, responsible for binding and facilitating oxygen transmission to tissues. In the four variations of sickle cell disease, systemic and ocular tissues become deprived of oxygen and undergo pathologic changes. Normal erythrocytes, containing normal hemoglobin, appear as flexible, pliable, biconcave discs. Erythrocytes affected by sickling disease lose their biconcave shape and their ability to efficiently move through the circulatory system. Variations in the alteration of the amino acid sequence on the globin chain produce variations in the disease's expression.