The deficiency of glucose transporter 2 (GLUT2), a monosaccharide carrier that is responsible for the transport of both glucose and galactose, results in hepatomegaly, fasting hypoglycaemia, post-prandial hyperglycaemia, transient neonatal diabetes mellitus (TNDM), generalized proximal tubular dysfunction, hypophosphataemic rickets and growth retardation. Here, SLC2A2 is linked to transient neonatal diabetes mellitus.