However, PTH concentrations are controlled within a target range of approximately 100–600 pg/mL in only approximately 50% of patients, with reported rates of low PTH (<100 pg/mL) and secondary hyperparathyroidism (SHPT, >600 pg/mL) of approximately 40% and 10%, respectively (4). The gene discussed is PTH; the disease is secondary hyperparathyroidism.