Question

Claudin expressed in the kidney tubule that could make the tubule impermeable to Mg2+ if abnormal

(A) Claudin-1
(B) Claudin-2
(C) Claudin-3
(D) Claudin-16

Answer 1

Claudin-16 is the protein in the kidney tubule responsible for making the tubule impermeable to
`Mg^(2+)` when abnormal.

Step-by-step explanation:

The Claudin expressed in the kidney tubule that could make the tubule impermeable to
`Mg^(2+)` if abnormal is Claudin-16 (D). Claudin proteins are crucial components of tight junctions in epithelial cells and have important roles in paracellular transport, which includes the selective movement of ions between cells. Abnormalities in Claudin-16 can disrupt the reabsorption of
`Mg^(2+)` and other ions, resulting in conditions such as familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC), where the kidney tubules become impermeable to magnesium, leading to its excessive loss in urine.