A 4 year old female child complains of weakness and pain in joints. Her parents are known case of sickle cell trait. Hb electrophoresis reveal HbS pattern. This disease occurs because of which base alteration?
The occurrence of the disease sickle-cell anemia due to a single base alteration (CTC + CAC in DNA, and GAG + GUG in RNA) is a classical example of the seriousness of mutations.
Satyanarayana- Biochemistry, 3rd edition, pg-549
CTC → CAC in DNA
GAG → GUG  in DNA
CTC → CAC  in  RNA
GAG → CAC  in RNA