TY - CHAP M1 - Book, Section TI - Chapter 434. Hemoglobinopathies A1 - Quinn, Charles T. A2 - Rudolph, Colin D. A2 - Rudolph, Abraham M. A2 - Lister, George E. A2 - First, Lewis R. A2 - Gershon, Anne A. PY - 2011 T2 - Rudolph's Pediatrics, 22e AB - Hemoglobin (Hb) is the oxygen-carrying protein within red blood cells (RBCs). It is composed of four globular protein subunits, called globins, and four oxygen-binding heme groups, which are attached to each globin. The two main types of globins are the α-globins and the β-globins, which are made in essentially equivalent amount in precursors of RBCs. Normal adult Hb (Hb A) has two α-globins and two β-globins (α2 β2). Genes on chromosomes 16 and 11 encode the α- and β-globins, respectively. There are also distinct embryonic, fetal, and minor adult analogs of the α- and β-globins, all of which are encoded by separate genes. Most important among these are the γ- and δ-globins, which are the fetal and minor adult analogs of α- and β-globin, respectively. See Chapter 429 for a discussion of the developmental changes in Hb production. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/03/28 UR - accesspediatrics.mhmedical.com/content.aspx?aid=7039788 ER -