<prompt> True about sickle cell disease are all, exceptSingle nucleotide change results in change of Glutamine to ValineSticky patch is generated as a result of replacement of a non polar residue with a polar residueHbs confers resistance against malaria in heterozygotesRFLP results from a single base change  <response>: Sickle cell anemia hemoglobin S disease : It is the most common of the red cell sicking diseases,is a genetic of the blood caused by a single nucleotide alteration in the beta-globin. A molecule of Hb S contains two normal alpha chains and two mutant beta-globin chains, in which glutamate at position six has been replaced with valine. Sickle cell anemia is a homozygous, recessive disorder. It is characterized by lifelong episodes of pain,chronic hemolytic anemia with associated hyperbilirubinemia and increased susceptibility to infection Heterozygotes contain both Hb S and Hb A.These individuals have sickle trait. They usually do not show clinical symptoms and can have normal lifespan. RFLP analysis:It is a diagnostic techniques for analyzing fetal DNA,rather than fetal blood,early detection of sickle cell anemia as well as other diseases. REF :Lippincotts textbook of biochemistry; 8th edition ;Page no :35,36 and 477. 