The International Paediatric Peritoneal Dialysis Network Registry that followed up nearly 900 children on PD found that clinical and radiological symptoms markedly increased when PTH exceeded 300 pg/mL, the risk of hypercalcemia increased with levels below 100 pg/mL and time-averaged PTH concentrations above 500 pg/mL were associated with impaired longitudinal growth [33]. This evidence concerns the gene PTH and Hypercalcemia.