And based on ROC curve analysis (Table 4), there was a high predictive value for seasons (G6PD activity) when predicting G6PD deficiency, with the AUC (CI 95%) of 1.000, 0.997, 1.000 (Figure 4A, Figure 4B, Figure 4C), and the optimal cut-off values of 21.80 U/dL (sensitivity, SS: 10.00%; and specificity, SP: 99.98%), 26.55 U/dL (SS: 100.00%; SP: 96.69%), 23.16 U/dL (SS: 100.00%; SP: 99.98%), in spring, summer and winter, respectively. This evidence concerns the gene G6PD and hyperinsulinemic hypoglycemia, familial, 4.