MTNR1B and gestational diabetes: In a meta-analysis, other polymorphisms were associated with the risk of developing GDM, such as the A allele of the rs1800629 polymorphism in the TNF-α gene (OR 2.69), the T-allele of the rs4402960 SNP in the IGF2BP2 gene (OR: 1.22), and the G-allele of the rs10830963 variant in the MTNR1B gene (OR: 1.28).