For instance, loss-of-function mutations in the sodium-Pi transport protein 2c (SLC34A3) gene have been associated with hypophosphatemic rickets with hypercalciuria (HHRH)29, a disorder that causes renal Pi wasting, rickets and kidney stones, but muscle weakness is less pronounced in these individuals when compared to the muscle weakness seen in X-linked hypophosphatemia (XLH)30 or tumor-induced osteomalacia (TIO)31. Here, SLC34A3 is linked to X-linked hypophosphatemia.