Patients with Dent disease have suppressed levels of FGF 23 which contributes to hypercalciuria, kidney stones, nephrocalcinosis and renal failure. Supplementation with phosphorus may reduce hypercalciuria.

Inclusion Criteria:

Patients will be recruited from those in the RKSC Dent Registry

1. Diagnostic criteria for Dent disease Observational arm include:

   1. <18 years old
   2. LMWP (at least 5 times above the upper limit of normal) and at least 1 of the following criteria: 1. Hypercalciuria, 2. Kidney stones, 3. Nephrocalcinosis, 4. Hypophosphatemia, 5. Renal phosphate leak, 6. Aminoaciduria, 7. Glucosuria without diabetes mellitus, 8. Hematuria, 9. Renal insufficiency, 10. Family history with x-linked inheritance or
   3. 1 of the above criteria (1-9) and confirmed genetic mutation of CLCN5 or OCRL1.

2. Diagnostic criteria for Dent disease Intervention arm include:

   1. >18 years old
   2. LMWP (at least 5 times above the upper limit of normal) and at least 1 of the following criteria: 1. Hypercalciuria, 2. Kidney stones, 3. Nephrocalcinosis, 4. Hypophosphatemia, 5. Renal phosphate leak, 6. Aminoaciduria, 7. Glucosuria without diabetes mellitus, 8. Hematuria, 9. Renal insufficiency, 10. Family history with x-linked inheritance or
   3. 1 of the above criteria (1-9) and confirmed genetic mutation of CLCN5 or OCRL1.

3. Idiopathic calcium nephrolithiasis with renal phosphate leak

   1. Male patients > 18 years old
   2. History of symptomatic calcium oxalate or calcium phosphate stone, hypercalciuria (>250 mg/24 hrs), renal phosphate leak (TMP/GFR <2.07 mg/dl)

4. Idiopathic calcium nephrolithiasis without renal phosphate leak

   1. Male patients > 18 years old
   2. History of symptomatic calcium oxalate or calcium phosphate stone, hypercalciuria (>250 mg/24 hrs), renal phosphate leak (TMP/GFR <2.07 mg/dl)

Exclusion Criteria:

1. Exclusion for Dent disease include: primary or secondary hyperparathyroidism, hyperthyroidism, chronic diarrhea states; intake of thiazide diuretics, glucocorticoids, or estrogens within one month of the study.
2. Exclusion criteria for calcium stone formers include: primary or secondary hyperparathyroidism, hyperthyroidism, estimated GFR <40 ml/mn/1.73m2, chronic diarrhea states; intake of thiazide diuretics, glucocorticoids, or estrogens within one month of the study.
3. Exclusion criteria include history of symptomatic or asymptomatic kidney stone disease; primary or secondary hyperparathyroidism; estimated GFR <40 ml/min/1.73m2, chronic diarrhea states; intake of thiazide diuretics, glucocorticoids, or estrogens within one month of the study.

Adverse Events were collected over a period of 7 days for each subjects