GCK-MODY(MODY2) and HNF1A-MODY(MODY3) are the two most common forms of the disease, accounting for more than 80% of patients with MODY from European populations (12, 13), whereas 80% of Japanese and Chinese patients with MODY do not have lesions in known MODY genes. This evidence concerns the gene GCK and maturity-onset diabetes of the young type 2.