A genetic disorder in African which reduces oxygen uptake is

Options

A. Haemophilia
B. Pernicious anaemia
C. Anaemia
D. Sickle cell anaemia

Answer

**Step-by-Step Solution:**

1. **Identify the Genetic Disorder:**
The question asks for a genetic disorder prevalent in Africans that reduces oxygen uptake. The options provided are hemophilia, pernicious anemia, anemia, and sickle cell anemia.

2. **Analyze the Options:**
- **Hemophilia** is a genetic disorder that affects blood clotting, not oxygen uptake.
- **Pernicious anemia** is related to vitamin B12 deficiency and does not directly relate to genetic inheritance.
- **Anemia** is a general term for a deficiency in red blood cells or hemoglobin but is not a specific genetic disorder.
- **Sickle Cell Anemia** is a known genetic disorder that affects hemoglobin and is prevalent in African populations.

3. **Confirm the Correct Answer:**
Sickle cell anemia is caused by a mutation in the hemoglobin gene, specifically a substitution of the 6th codon in the beta chain of hemoglobin where glutamic acid is replaced by valine. This mutation leads to the production of abnormal hemoglobin (HbS), which causes red blood cells to become rigid and sickle-shaped, reducing their ability to carry oxygen.

4. **Summarize the Main Symptoms:**
The primary symptom of sickle cell anemia is a decrease in oxygen uptake due to the altered shape and function of red blood cells, leading to various complications.

5. **Final Answer:**
The genetic disorder in Africans that reduces oxygen uptake is **Sickle Cell Anemia**.

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