The type mutation that leads to replacement of valine for glutamate in sickle cell disease is: (A) Point mutation, (B) Silent mutation, (C) Nonsense mutation, (D) Any of above
Answer is A. Sickle-cell anemia is caused by apoint mutation in the b-globin chain of hemoglobin, causing the hydrophilic amino acid glutamic acid to be replaced with the hydrophobic amino acid valine at the sixth position. The b-globin gene is found on the sho arm of chromosome 11. Ref ganong's review of medical physiology 25e