A scatter diagram of the 4-quadrant plots showed that 16 genes (Cdipt, Mfhas1, Slc7a14, Gm38393, Pcdha6, Paqr9, Rexo2, Tbc1d30, Akap6, Kcnf1, Sv2c, Arhgap26, Ank1, Arhgap23, Shank2, Sez6l) were identified as hypermethylated and down-regulated, and 9 genes (Thtpa, Sema5b, Lima1, Gse1, Tmem98, Mpped2, Peg12, Mcm10, Mid1) were hypomethylated and up-regulated in the GDM group. The gene discussed is MID1; the disease is gestational diabetes.