Permanent neonatal diabetes mellitus (PNDM) is usually diagnosed within the first 6 months of birth, with a monogenic etiology indentified in about 60% of cases (Diabetologia 2002;45:798–804). Dominant mutations in three genes (KCNJ11, ABCC8, and INS) are most commonly involved, but autosomal and X-linked recessive mutations have been identified in 10 other genes. Most children present with diabetes alone; however, in some cases, diabetes can occur in the context of a more complex multisystem syndrome – this is especially the case for the non-dominant forms.