Compared with patients with MGD, patients with SGD had higher preoperative calcium (11.0 ± 0.8 vs 10.5 ± 0.8 mg/dL, P <.001) and higher preoperative PTH (109 [83-151] vs 89 [65-125] pg/mL, P <.001). The gene discussed is PTH; the disease is specific granule deficiency.