Hemoglobin is a model system to illustrate the deleterious effects of mutations.Which of the following statements about deleterious mutations in human hemoglobin genes is false?
A) Hemoglobin A and hemoglobin S differ at only one amino acid position B) In hemoglobin S, the substitution of valine for glutamic acid causes an aggregation of hemoglobin molecules not found in hemoglobin A C) The molecular difference between hemoglobin A and hemoglobin S was identified by protein sequence before nucleotide sequence D) The valine to glutamic acid substitution is the only amino acid change so far identified in the b chain of hemoglobin E) Homozygous (Hbsb/Hbsb) leads to severe hemolytic anemia, which is often fatal.