7
A 16-year-old adolescent presents with tetany. Laboratory results show hypokalemia, metabolic alkalosis, and severe hypomagnesemia. Urinary calcium excretion is low. Which transporter is defective?
A
Na-Cl cotransporter in distal tubule
B
Na-K-2Cl transporter in loop of Henle
C
Epithelial sodium channel in collecting duct
D
Glucose transporter in proximal tubule