PTH and hyperparathyroidism: Family 2 (Figure 4A, right panel): The proband (individual II-1), a 34-year-old female, presented with a serum ionized calcium concentration (iCal, mmol/liter) of 1.41 (normal range, 1.12–1.31) and a PTH level of 215 pg/mL (normal range, 10–65), consistent with hyperparathyroidism.