The incidence of gestational diabetes mellitus (GDM) is currently dramatically increasing throughout the world. The relevant studies of origin and pathogenesis of GDM are of great clinical and scientific value taking into account the intimate association of GDM with serious perinatal complications, including preeclampsia, preterm labor, fetal macrosomia, as well as long-term effects such as the high risk of metabolic syndrome and type 2 diabetes mellitus (T2DM). The pathogenic mechanisms of GDM are rather similar to those of other diabetes, especially T2DM, thus suggesting that GDM is a common multifactorial disorder involving numerous genetic and provocative exogenous factors. The data in favor of inherited predisposition to GDM are briefly discussed and a short overview of the known GDM candidate genes is given. According to present knowledge, the gene network of GDM includes dozens of genes and is rather similar to that in GDM. The features of gene network associated with GDM and the ones known for other types of DM are outlined. Special attention is given to the known GDM biomarkers, which are especially important for understanding of the molecular genetic and epigenetic mechanisms of GDM development, its early predictive diagnosis, efficient prevention and personalized treatment.