Deficiency of enzyme ADA leads to .

Options

A. AIDS
B. SCID
C. Anaphylactic shock
D. both (1) and (3)

Answer

**Step-by-Step Solution:**

1. **Identify the Enzyme**: The enzyme in question is Adenosine Deaminase (ADA).

2. **Understand the Function of ADA**: ADA is crucial for the development of lymphocytes, which are a type of white blood cell (WBC) that plays a vital role in the immune system.

3. **Consequences of ADA Deficiency**: When there is a deficiency of ADA, the production of lymphocytes is impaired. This leads to a weakened immune system, making individuals more susceptible to infections.

4. **Recognize the Disease Associated with ADA Deficiency**: The deficiency of ADA is specifically associated with a condition known as Severe Combined Immunodeficiency (SCID). This condition is characterized by a severely compromised immune system.

5. **Distinguish SCID from Other Conditions**: It is important to note that SCID is not the same as AIDS, which is caused by the HIV virus, nor is it related to anaphylactic shock, which is an allergic reaction.

6. **Conclusion**: Therefore, the deficiency of the enzyme ADA leads to SCID.

**Final Answer**: The deficiency of enzyme ADA leads to SCID (Severe Combined Immunodeficiency).

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