All are the causes of nephrocalcinosis in granulomatous disease except -
In granulomatous diseases ,granulomas have 1alpha hydroxylase activity . So there is increased conversion of 25(OH) D to 1,25(OH) 2 D. Increased active vitamin d INCREASES-reabsorption of calcium in PCT, bone resorption ,absorption of ca in intestine-resulting in hypercalcemia. Hypercalcemia results in-nephrocalcinosis, nephrolithiasis ,nephrogenic diabetes insipidus . Ref:Harrison 20 th edition pg no 2603
Increased absorption of ca from intestine
Increased conversion to 1,25 (OH )2 D
Increased bone resorption
Mutation in calcium sensing receptor
Kidney