Moreover, isolated type 2 diabetes mellitus has been reported in association with the heterozygous c.712C > A (p.His238Asn) DNAJC3 mutation (Kulanuwat et al., 2018); however, the same mutation was also observed in two non-diabetic individuals in the study and has been seen at a low frequency in the ExAC database, questioning the role of DNAJC3 as a dominant type 2 diabetes-associated gene. This evidence concerns the gene DNAJC3 and type 2 diabetes mellitus.