PTH and Hypercalciuria: First described in 1985 by Tieder [149], this inherited disease is characterised by decreased renal Pi reabsorption, hypophosphataemia, vitamin D3 refractory rickets, hyperphosphaturia, hypercalciuria, elevated circulating 1, 25(OH)2D3 levels, and low serum parathyroid hormone (PTH) levels, leading to growth retardation, limb deformities, bone pain, muscle weakness, rickets and osteomalacia [16, 87, 149, 150].