Sickle Cell Anemia Blood Disorder

             Sickle cell anemia or disease is a type of blood disorder that is passed on genetically, from parent to child. When one is born with sickle cell it will not leave and one cannot grow out of it. The disease is hereditary and one cannot contract it from someone that has it. .

             How Sickle Cell Anemia works:.

             Sickle cell is inherited from one's own parents. It is caused when both parents each give their child a damaged gene that contains the disorder. "The gene containing Sickle Cell is located on chromosome 11 of the gametes."1 When the child only receives one gene which contains sickle cell while the other gene inherited is normal, the child does not have sickle cell disease but sickle cell trait. The disorder results from the presence of an abnormal hemoglobin, the "iron-containing pigment in the red blood cells of vertebrates that increases the oxygen-carrying capacity of the blood."2 The abnormal hemoglobin in place of the normal one is called sickle cell hemoglobin (Hb S). "Normal adult hemoglobin (Hb A) is made of four long chains of amino acid units which are connected to a complicated iron-containing organic molecule called heme."3 Two of the four chains have 141 amino acid units called the alpha chains. The other two chains have 146 amino acid units each and they're called beta chains. In Sickle Cell anemia the sixth codon from the beta chains reads GTG instead of GAG. Valine is substituted for a glutamic nucleotide. This results in a single amino acid change at the sixth position on the beta chain in the hemoglobin. The change seems small enough to go unnoticed, just one nucleotide in the sixth codon which results in the change of one amino acid out of 146 in the chain, but the insignificant change starts an electrical charge in the molecule changing its behaviour.

             When oxygen is plentiful Hb A and Hb S act the same and carry out the same activities, but when there is a lack of oxygen Hb A remained in its liquid form but Hb S grew thicker and more rigid forming a crystal-like shape.

Related Essays: