RT Book, Section
A1 Quinn, Charles T.
A2 Rudolph, Colin D.
A2 Rudolph, Abraham M.
A2 Lister, George E.
A2 First, Lewis R.
A2 Gershon, Anne A.
SR Print(0)
ID 7039788
T1 Chapter 434. Hemoglobinopathies
T2 Rudolph's Pediatrics, 22e
YR 2011
FD 2011
PB The McGraw-Hill Companies
PP New York, NY
SN 978-0-07-149723-7
LK accesspediatrics.mhmedical.com/content.aspx?aid=7039788
RD 2024/04/19
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.