INS and maturity-onset diabetes of the young type 10: However, many heterozygous INS gene mutations that alter the proinsulin coding sequence can cause diabetes by triggering proinsulin misfolding, which may exhibit dominant-negative gain-of-toxic-function [6]—a syndrome sometimes referred to as Mutant INS-gene-induced Diabetes of Youth (MIDY [7], also known as MODY10 [8]).