This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bater syndrome, Gitelman syndrome, Liddle and Comparison with SIADH, Subject name: Medicine
In Bater syndrome the defect lies in? 
Select and explain. 
A. Distal convoluted tubule, B. Thick ascending limb of loop of Henle, C. Thin ascending limb of loop of Henle, D. Proximal convoluted tubule
B: Thick ascending limb of loop of Henle
Answer: B: Thick ascending limb of loop of Henle 
Explanation: Bater Syndrome- defect in thick ascending limb of loop of Henle *Loss of function of (Na+ Cl- K+ co transpoer) *Damage to ROMK & Cl- channel C/F: 1. Hypokalemia, salt wasting 2. Normal BP 3.Met. Alkalosis Dx: 24 hr. urine chloride : elevated *24 hr. urine Ca2+ : elevated DOC: indomethacin