Higher direct FINS levels [13.6 (8.7, 21.8) vs. 10.2 (7.6, 14.0) μIU/mL, p < 0.001)] and a higher prevalence of hyperinsulinemia (43.8% vs. 21.3%, p < 0.001) were observed in subjects with C-INS. The gene discussed is INS; the disease is hyperinsulinism.