Our study showed that several risk variants for obesity or metabolic diseases (FTO rs1121980, KCNQ1 rs163182, MC4R rs12970134, and PROX1 rs340841) were also associated with GDM, giving further evidence that GDM and obesity/metabolic diseases may share a similar genetic background. The gene discussed is FTO; the disease is obesity due to melanocortin 4 receptor deficiency.