Question

A patient shows frequent fatigue and weakness. Blood examination reveals that some red blood cells are sickle-shaped. Based on these observations, answer the following:
(a) Identify the reason for this disease.
(b) In what other ways does this genetic defect affect the body?

Hint:

Remember: Sickle cell anaemia is caused by a mutation in haemoglobin gene, leading to abnormal RBC shape and reduced oxygen-carrying capacity.

Answer 1

Step 1: Identify the disease.
The presence of sickle-shaped red blood cells indicates that the patient is suffering from sickle cell anaemia, a genetic blood disorder.
Step 2: Cause of the disease.
This disease is caused by a mutation in the gene responsible for haemoglobin formation. The normal haemoglobin (HbA) is replaced by abnormal haemoglobin (HbS), which causes red blood cells to become rigid and sickle-shaped.
Step 3: Answer part (a).
Thus, the reason for this disease is a genetic mutation in haemoglobin leading to formation of abnormal HbS.
Step 4: Effects of this defect on the body.
Due to the abnormal shape, red blood cells lose their flexibility and may block blood vessels. This leads to:
- Reduced oxygen supply to tissues
- Pain and swelling due to blocked capillaries
- Damage to organs over time
- Shortened lifespan of red blood cells causing anaemia
Step 5: Answer part (b).
Therefore, this defect affects the body by causing poor oxygen transport, blockage of blood vessels, organ damage, and anaemia.