Rare inheritable conditions may present without warning in the neonatal period and thus lead curious staff to institute expansive clinical investigations. Non-ketotic hyperglycaemia (NKH) in a normal fully grown male infant following an essentially eventful pregnancy associated with unrelated condition provoked much clinical curiosity. NKH should therefore be included as a differential diagnosis in an unwell neonate presenting with hiccoughs, seizures, myotonic jerks, and hypotonia as our very unique case clearly demonstrated.