Association between single nucleotide polymorphism of rs4753426 of melatonin receptor 1B gene and gestational diabetes mellitus
Objective: To investigate the genotypic and allele frequency differences of melatonin receptor 1B (MTNR1B)-rs4753426 between gestational diabetes mellitus (GDM) pregnancies and normal pregnancies, and to explore the association between single nucleotide polymorphism (SNP) of rs4753426 and gestational diabetes mellitus.
Methods: Totally 93 GDM pregnancies and 165 normal pregnancies were recruited from the Affiliated Hospital of Qingdao University. The age, gestational weeks, height, early pregnant weight, and the levels of fasting plasma glucose (FPG), fasting insulin (FIN) were determined in every participants. By using PCR and DNA sequencing, we detected the distribution of the rs4753426 genotypes and alleles in all individuals. The homeostasis model assessment-insulin resistance (HOMA-IR) and the homeostasis model assessment-β cell function (HOMA-β) were calculated. The allele and genotype frequencies and the FPG, FIN, body mass index (BMI), HOMA-IR, HOMA-β levels between GDM group and control group were compared.
Results: (1)The genotype frequencies in the GDM group and the control group of rs4753426-CC, CT, TT were 72.0% (67/93), 21.5% (20/93), 6.5% (6/93), and 53.9% (89/165), 40.0% (66/165), 6.1% (10/165) respectively. The allele frequencies in the GDM group and the control group of T and C were 17.2% (32/186), 82.8% (154/186) and 26.1% (86/330), 73.9% (244/330) respectively. There were statistical differences in genotype frequencies and allele frequencies between two groups (all P < 0.05). (2)The levels of FPG, FIN and HOMA-IR in the GDM group were obviously higher than those in the control group (P < 0.05). The level of HOMA-β was lower in the GDM group than that of the control group (P < 0.05).(3)The FPG of CC and CT genotypes was higher than that of TT genotype in the GDM group (P < 0.05), while the level of HOMA-β was lower than that of TT genotype (P < 0.05).
Conclusions: The MTNR1B-rs4753426 SNP is associated with the pathogenesis of GDM, and rs4753426 is the predisposing locus of GDM. The C-allele is the susceptibility allele of GDM.