Amutation in the proteins that form tight junctions could decrease the ability of the proximal tubular cells to connect to each other. this would result in an increase in the movement of substances out of the tubule via the route.

This would result in an increase in the movement of substances out of the tubule via the Paracellular route.

Explanation:

Paracellular Transport:

The transportation of the substances or molecules by passing between the neighboring epithelial cells. It is a passive transport. This type of transportation is not suitable for the macro-molecules and is used for specific size molecules.