Endocrinological Disorders Matching 

This question requires matching specific endocrinological disorders with their characteristic investigation results.

Matching List I with List II

Let's match each disorder from List I to its corresponding investigation result in List II:

• A. Hypothyroidism: This condition involves underactive thyroid glands, leading to decreased levels of thyroid hormones ($T_3, T_4$). Consequently, the pituitary gland often increases the secretion of Thyroid Stimulating Hormone (TSH) to compensate. This matches with item 4 (TSH levels are increased and $T_3, T_4$ levels are decreased).
• B. Cushing's syndrome: Characterized by prolonged exposure to high cortisol levels. While direct cortisol measurements are key, conditions involving excess adrenal androgens, sometimes associated with Cushing's syndrome, can result in increased urinary 17-ketosteroids. This matches with item 2 (Increased urinary 17-ketosteroids).
• C. Pheochromocytoma: This is a tumor of the adrenal medulla that produces excessive amounts of catecholamines (like adrenaline and noradrenaline). A key diagnostic finding is the increased excretion of these substances in the urine. This matches with item 1 (Increased urinary excretion of catecholamines).
• D. Hypoparathyroidism: This disorder involves insufficient production of parathyroid hormone (PTH). PTH regulates calcium and phosphate levels. Low PTH leads to low blood calcium levels (hypocalcaemia) and high blood phosphate levels (hyperphosphataemia). This matches with item 3 (Hypocalcaemia and hyperphosphataemia).

Conclusion

Based on the matching:

• A matches with 4
• B matches with 2
• C matches with 1
• D matches with 3

The correct combination is A-4, B-2, C-1, D-3.