PTH and Hypercalcemia: One of the most impressive pediatric case of HBS was reported in 1998, a 6-year-old girl who developed neurological anomalies since having hypercalcemia (detected within her first days of life); the total serum calcium was one the highest at such young age (of 25.5 mg/dL) in association with increased PTH (of 1550 pg/mL) [90].