The mutation described in your scenario is most likely a substitution mutation, specifically a single nucleotide substitution that leads to a different amino acid being incorporated into the hemoglobin protein. This type of mutation is famously illustrated by the genetic condition known as sickle cell disease, which results from a single nucleotide change in the hemoglobin gene (specifically, the substitution of adenine (A) with thymine (T) at a particular position). This substitution causes the production of mutant hemoglobin known as hemoglobin S (HbS), leading to the deformation of red blood cells into a sickle shape.
To clarify the other types of mutations mentioned:
- Insertion: This involves the addition of one or more nucleotides into the DNA sequence, potentially leading to a frameshift and a completely different amino acid sequence downstream of the mutation.
- Deletion: This refers to the loss of one or more nucleotides from the DNA sequence, which can also result in a frameshift mutation.
- Duplication: This involves the repetition of a segment of DNA, which can lead to an altered protein product through increased dosage of certain genes.
In conclusion, the mutation leading to sickle-shaped red blood cells is most accurately described as a substitution mutation.
1 answer