PDE4C and hereditary endocrine growth disease: ANCOVA revealed significant differences (with α < 0.05) at 11 CpG sites in all genes between the healthy group and the total growth disorder group, and at 12 CpG sites in all genes between the healthy group and the short stature subgroup; in the non-short stature group, only 3 CpG sites in the genes PDE4C, ELOVL2 and RPA2 presented significant differences.