After obtaining written informed consent from her parents, a genetic analysis was conducted to evaluate glucometabolic disorders using a next-generation sequencing panel consisting of 17 genes commonly mutated in monogenic diabetes (ABCC8, GATA6, GCK, GLUD1, HNF1A, HNF1B, HNF4A, INS, INSR, KCNJ11, NEUROD1, PDX1, AIRE, FOXP3, HADH, KLF11, and WFS1). This evidence concerns the gene GCK and diabetes mellitus.