INS and diabetes mellitus: INS gene biallelic mutations are the second most common cause of permanent neonatal diabetes mellitus after the ATP-sensitive K+ (KATP) channels defects (34), instead INS monoallelic mutations are implicated in a rare MODY subtype (INS-MODY or MODY 10), (MIM # 613370) (35–38), especially in European countries (39–44).