Question

What is the DNA mutation in sickle cell anemia?

Answer 1

In sickle cell anemia, there is a specific DNA mutation that occurs. It's called a point mutation, where a single nucleotide in the DNA sequence is changed. In this case, the mutation affects the gene that codes for the beta-globin protein, which is a component of hemoglobin. Specifically, a substitution occurs where the nucleotide adenine (A) is replaced by thymine (T) in the DNA sequence. This mutation leads to the production of abnormal hemoglobin, causing the red blood cells to become sickle-shaped.

Answer 2

The DNA mutation in sickle cell anemia is a single base substitution in the beta-globin gene that causes a missense mutation, leading to the production of abnormal hemoglobin and sickle-shaped red blood cells.

Step-by-step explanation:

DNA Mutation in Sickle Cell Anemia:

The DNA mutation responsible for sickle cell anemia is a single base substitution in the beta-globin gene. It involves the replacement of adenine (A) with thymine (T) at the 17th nucleotide of the hemoglobin gene, leading to the substitution of the amino acid valine for glutamic acid in the protein sequence. This alteration is known as a missense mutation. The affected DNA sequence changes from CCTGAGG to CCTGTGG. This seemingly small change has a profound effect, as it causes the hemoglobin in red blood cells to polymerize under low oxygen conditions, resulting in the distinctive sickle or crescent shape of the erythrocytes. These sickle-shaped cells can obstruct capillary flow and impair oxygen delivery, leading to the symptoms of anemia.