In case of atypical features or autosomal dominant inheritance, less common forms of diabetes should be considered in the differential diagnosis and, in this case, a custom panel including several genes associated to MODY and neonatal diabetes (i.e., HNF4A, GCK, HNF1A, PDX1, HNF1B, NEUROD1, KLF11, CEL, PAX4, INS, BLK, ABCC8, KCNJ11, APPL1, INSR, ZFP57, and PLAGL1) through Next Generation Sequencing analysis should be performed. Here, HNF1A is linked to diabetes mellitus.