The U.S. infant mortality rate generally declined throughout the 20th century, from 100 infant deaths per 1,000 live births in 1900 to 6.89 infant deaths per 1,000 live births in 2000.
hemoglobinopathies are genetic inherited disorders of hemoglobin the oxygen carrying protein of the red blood cells the hemoglobin molecule is composed of four separate polypeptide chains of amino acids two alpha chains and two beta chains as well as four iron bearing heme groups that bind oxygenemoglobinopathies are genetic inherited disorders of hemoglobin the oxygen carrying protein of the red blood cells the hemoglobin molecule is composed of four separate polypeptide chains of amino acids two alpha chains and two beta chains as well as four iron bearing heme groups that bind oxygen
There is more than one hemoglobin gene: in humans, hemoglobin A (the main form of hemoglobin present) is coded for by the genes, HBA1, HBA2, and HBB. The amino acid sequences of the globin proteins in hemoglobins usually differ between species. These differences grow with evolutionary distance between species.