Answer:
In Sickle Cell Anemia:
- Mutation that occurs in DNA is due to the substitution of thymine base by adenine base.
- Change in mRNA consists of a change of the GAA codon to GUA, which codes for a different amino acid.
- The change that occurs in the synthesized protein is the substitution of glutamic acid by valine, the consequence of which is the structural alteration of this protein.
Explanation:
Sickle cell anemia is a disease that is transmitted from parent to child in an autosomal recessive inheritance pattern. It is due to a mutation that is capable of altering the shape of the erythrocyte, as well as its ability to circulate and carry oxygen.
- First, a puntual genetic mutation occurs, where the sequence of DNA bases that determines the synthesis of the hemoglobin β-chain, by suffering the substitution of thymine by an adenine: CTT → CAT.
- The transcription of this altered sequence to mRNA results in the change of the GAA codon to GUA, which encodes a different amino acid.
- Once the β-chain is synthesized, in its structure there is a change in the amino acid sequence, due to the substitution of glutamic acid by valine.
The interaction of valine with the other amino acids of the protein promotes a structural change, responsible for the deformation of the red blood cell that characterizes sickle cell anemia.
