Neonatal diabetes mellitus (NDM), often referred to clinically as congenital diabetes mellitus (CDM), represents a rare and complex group of metabolic disorders characterized by persistent hyperglycemia occurring within the first six months of life [1] unlike the more prevalent type 1 diabetes (T1D), which is driven by autoimmune destruction of pancreatic β-cells and involves polygenic susceptibility, NDM is predominantly a monogenic disorder caused by mutations in single genes critical for pancreatic development, β-cell survival, or insulin secretion function [2]. The gene discussed is INS; the disease is type 1 diabetes mellitus.