There was a significant difference between patients with and without parathyroid adenoma regarding the preoperative serum Ca level (11.21 ± 0.41 mg/dL versus 9.5 ± 0.36 mg/dL, respectively), preoperative serum P level (2.3 ± 0.3 mg/dL versus 3.7 ± 1.4 mg/dL, respectively), and preoperative serum PTH level (142 ± 89.3 pg/mL versus 53.7 ± 11.5 pg/mL, respectively) (p < 0.001 overall). This evidence concerns the gene PTH and parathyroid gland adenoma.