## **Core Concept**
A missense mutation is a type of point mutation where a single nucleotide change results in a codon that codes for a different amino acid. This change can lead to the substitution of one amino acid for another in the resulting protein. Missense mutations can have varying effects on the protein's function, depending on the location and the specific amino acid substitution.

## **Why the Correct Answer is Right**
The correct answer, **Sickle Cell Anemia**, is a classic example of a missense mutation. It is caused by a point mutation in the HBB gene that codes for the beta-globin subunit of hemoglobin. The mutation results in the substitution of glutamic acid (coded by GAG) with valine (coded by GTG) at position 6 of the beta-globin chain. This change leads to the production of abnormal hemoglobin, known as sickle hemoglobin or hemoglobin S, which under certain conditions, causes red blood cells to assume a sickle shape.

## **Why Each Wrong Option is Incorrect**
- **Option A:** [Not provided, assuming it is another genetic disorder or mutation type] - Without specifics, it's hard to address directly, but if it's not related to a well-known missense mutation effect, it would be incorrect.
- **Option B:** [Not provided, assuming another option] - Similarly, without details, it's challenging to directly refute, but if it doesn't accurately describe a classic missense mutation example, it's incorrect.
- **Option C:** [Not provided, assuming another option] - This would be incorrect if it does not represent a condition caused by a missense mutation.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that sickle cell anemia is not only a classic example of a missense mutation but also a significant cause of morbidity worldwide, particularly in regions where malaria is or was prevalent. The disease illustrates how a single amino acid change can have profound effects on protein function and human health.

## **Correct Answer:** B. Sickle Cell Anemia