INS and Hyperglycemia: FD is encountered mainly in East-Asian populations and rarely in Caucasians, featured by abrupt β-cell destruction, profound hyperglycemia, DKA despite almost normal HbA1c values, no insulin secretion in response to glucagon test, increased serum pancreatic enzyme, and close correlation with HLA class II haplotypes (DRB1*04:05–DQB1*04:01 and DRB1*09:01–DQB1*03:03) [81,113].