Question

In Bartter syndrome, the defect is seen in:

• A. Defect in PCT
• B. Defect in DCT
• C. Defect in thick ascending limb of loop of Henle
• D. None

Hint:

It behaves like a permanent loop diuretic; think where they act.

Answer 1

The Correct Option is C

Step 1: Bartter syndrome is an autosomal recessive renal tubular disorder that mimics chronic loop diuretic use.

Step 2: The genetic defect lies in the thick ascending limb of the loop of Henle. Mutations affect the Na-K-2Cl cotransporter, the potassium channel (ROMK) or the chloride channel, impairing salt reabsorption and the kidney's concentrating ability.

Step 3: A proximal tubule (PCT) or distal convoluted tubule (DCT) defect would describe other disorders; Gitelman syndrome, for example, affects the DCT. Therefore the answer for Bartter syndrome is the thick ascending limb of the loop of Henle.