Lysine codon 392 (AAA) in exon 13 was changed to arginine (AGA) (p.K392R) using an sgRNA and an ssODN template with CRISPR/Cas9 technology. The mutation, in the DNA-binding domain of the encoded peptide, represents the same human gain-of-function mutation (NM_011486.3:c.1175A>G) that affects diabetes severity. (J:342716)