SCD is caused by a recessive, single-nucleotide mutation in the beta globin gene of Hgb. All of the following are TRUE about Sickle cell disease, EXCEPT:
When the sickle Hgb unloads its O2, the normal conformational change exposes the valine at position 6 to the surface creating a "hydrophobic (sticky) patch". The hydrophobic patch on one deoxygenated Hgb molecule can interact with the hydrophobic patch on a second Hgb molecule, creating stiff Hgb polymers. These internal polymers cause the RBC to stiffen and adopt abnormal shapes, including a crescent or "sickle" shape that gives the disease its name. Ref: Poeus M., Mantanona T. (2012). Chapter 14. Blood. In L.W. Janson, M.E. Tischler (Eds), The Big Picture: Medical Biochemistry.
Single nucleotide change results in change of Glutamine to Valine
Sticky patch is generated as a result of replacement of a non polar residue with a polar residue
HbS confers resistance against malaria in heterozygotes
RFLP results from a single base change