Thus, NHE3 appears to play a crucial role in PT receptor‐mediated endocytosis, suggesting that ClC‐5‐dependent NHE3 dysfunction might be an important factor in the cascade of events leading to the common DD1 phenotype that includes LMWP, hypercalciuria and hypophosphatemia. The gene discussed is SLC9A3; the disease is hypophosphatemia.