TY - JOUR T1 - Disorders of hemoglobin: Genetics, pathophysiology, and clinical management AU - Mehta P Y1 - 2012/03/28 N1 - 10.1001/jama.2012.348 JO - JAMA SP - 1319 EP - 1319 VL - 307 IS - 12 N2 - There are hundreds of different hemoglobins; some are specific for embryonic, fetal, and adult life, and others are variants. Some variants, such as hemoglobin S, have conferred protection for whole populations against malaria and other infectious diseases by trapping parasites within their membranes, allowing the parasites to be cleared in the reticuloendothelial system. Two prototypical abnormalities of hemoglobin account for most diseases: qualitative defects in heme (ie, sickle cell disease and its variants) and quantitative defects in the globin chain (ie, thalassemia). These latter abnormalities have become much better understood and amenable to study since the cloning and sequencing of human globin genes. More than a thousand globin chain variants have now been discovered, allowing for characterization of disease, elucidation of gene effects on protein encoding, and precise prenatal and postnatal diagnosis. SN - 0098-7484 M3 - doi: 10.1001/jama.2012.348 UR - http://dx.doi.org/10.1001/jama.2012.348 ER -