The Molecular Basis of Sickle Cell Hemoglobin Is

Question

The molecular basis of sickle cell hemoglobin is:
A)a frameshift mutation.
B)a single nucleotide substitution.
C)a translocation event.
D)a virus induced inversion.
E)exposure to a chemical mutagen.

Accepted Answer

Sickle cell hemoglobin is caused by a single nucleotide substitution in the beta-globin gene. Specifically, a thymine is substituted for an adenine, resulting in a change from glutamic acid to valine at position 6 of the beta-globin protein. This change in amino acid sequence alters the shape of the red blood cells, causing them to take on a characteristic sickle shape and leading to the symptoms of sickle cell disease.