As absolute insulin deficiency is not typical for HNF1A-MODY persons, the development of diabetic ketoacidosis (DKA) in a person with HNF1A-MODY is rare and just two previous cases are described [6, 7], it is estimated that approximately 80% of MODY are misdiagnosed as type 1 or type 2 diabetes mellitus [8]. This evidence concerns the gene HNF1A and diabetes mellitus.