Cretinism is caused by

Options

A. hypothyroidism
B. hypoparathyroidism
C. hyperthyroidism
D. hyperparathyroidism

Answer

### Step-by-Step Solution:

1. **Understanding Cretinism**: Cretinism is a condition characterized by physical and mental developmental delays. It is primarily associated with deficiencies in thyroid hormones.

2. **Identifying the Cause**: The main cause of Cretinism is the hyposecretion (underproduction) of thyroid hormones, particularly thyroxine (T4). This hormone is crucial for normal growth and development, especially of the nervous system.

3. **Effects of Thyroid Hormone Deficiency**: When there is insufficient thyroxine during pregnancy, it can lead to various developmental issues in the fetus, including:
- Low mental IQ (intelligence quotient)
- Slow physical growth and delayed milestones
- Slow heartbeat
- Protruding tongue
- Delayed sexual development

4. **Differentiating Related Conditions**: It is important to differentiate Cretinism from other conditions caused by thyroid hormone imbalances:
- **Hypoparathyroidism** leads to tetany, not Cretinism.
- **Hyperthyroidism** is associated with Graves' disease.
- **Hyperparathyroidism** can cause osteoporosis.

5. **Conclusion**: Based on the understanding that Cretinism is specifically caused by the hyposecretion of thyroid hormones, the correct answer to the question is hypothyroidism.

### Final Answer:
Cretinism is caused by hyposecretion of thyroid hormones (hypothyroidism).

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