Hematological Complications in Obstetrics, Pregnancy, and Gynecology: Hemoglobinopathies in pregnancy

摘要: Introduction All human hemoglobin is composed of two α -globin-like chains and non- -globin that combine to form a tetramer. Normal adults have three types, HbA ( 2 β 2; ∼ 96%), HbF γ 1%), δ ; 3%). The amino acid sequence, or primary structure each globin chain differs; dissimilarities between - are greater than the variations among globins -like gene cluster, e.g. -, -globin. Despite these differences their similarities even as all alike secondary tertiary function similarly. Human ideally suited for its tasks – primarily oxygen uptake in lungs delivery tissues. A sigmoidal shaped curve, so critical this transport, result interactions individual subunits As function, shape dissociation curve shows totally deoxygenated slow become oxygenated, but oxygenation proceeds, reaction heme with accelerates; reverse also true. Hemoglobin has other functions CO exchange control vascular tone by nitric oxide (NO) can modulate shifts oxygen-hemoglobin caused temperature, pH, organic phosphates. Different classes mutations alter structure, synthesis hemoglobin. More 1,000 structurally abnormal hemoglobins been characterized number thalassemia-causing exceeds 200.