Which is X - linked recessive trait with locus in Xq 28 and related to factor VIII

Options

A. Haemophilia A
B. Haemophilia B
C. Haemophilia C
D. Christmas disease

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for an X-linked recessive trait located at locus Xq28 that is related to factor VIII.

2. **Identifying the Options**: The options provided are:
- Hemophilia A
- Hemophilia B
- Hemophilia C
- Christmas disease

3. **Analyzing Hemophilia A**:
- Hemophilia A is characterized by the absence of antihemophilic globulin (factor VIII).
- It is an X-linked recessive disorder.
- The genetic locus for Hemophilia A is indeed Xq28.
- Therefore, Hemophilia A is directly related to factor VIII deficiency.

4. **Analyzing Hemophilia B**:
- Hemophilia B is caused by a deficiency in factor IX, not factor VIII.
- It is also an X-linked recessive disorder but does not fit the criteria of the question.

5. **Analyzing Hemophilia C**:
- Hemophilia C is related to a deficiency in factor XI and is not X-linked; it affects both sexes.
- It is also known as Plasma Thromboplastin Antecedent (PTA) deficiency.

6. **Analyzing Christmas Disease**:
- Christmas disease is another name for Hemophilia B, which is related to factor IX, not factor VIII.
- Therefore, it is also not the correct answer.

7. **Conclusion**: Based on the analysis, the only option that fits the criteria of being an X-linked recessive trait at locus Xq28 and related to factor VIII is **Hemophilia A**.

### Final Answer:
**Hemophilia A**

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