Leptin receptor gene polymorphisms c.668A>G and c.1968G>C in Sudanese women with preeclampsia: a case-control study

Leptin receptor gene (LEPR) variants may affect the leptin levels and act as a risk factor for preeclampsia. Two LEPR gene missense variants rs1137101 (c.668A>G) and rs1805094 (c.1968G>C) were investigated in Sudanese women with preeclampsia.

A matched case-control study (122 women in each arm) was conducted in Saad Abualila Maternity Hospital in Khartoum, Sudan from May to December 2018. The cases were women with preeclampsia and the controls were healthy pregnant women. Genotyping for LEPR gene variants c.668A>G and c.1968G>C was performed using polymerase chain reaction-restriction fragment length polymorphism. Logistic regression models (adjusted for age, parity, body mass index and hemoglobin level) were conducted.

Genotype frequency of LEPR gene variants c.668A>G and c.1968G>C was in accordance with Hardy-Weinberg equilibrium (P > 0.05) in the controls. Allele G in LEPRc.668A>G variant was significantly more frequent in the cases compared with the controls [43.4% vs. 10.2%; OR = 6.44; 95%CI (3.98-10.40); P < 0.001]. In variant LEPRc.668A>G, genotype AG was the prevalent genotype in the cases compared with the controls, and it was significantly associated with preeclampsia risk [37.7% vs. 15.5%; AOR = 3.48; 95%CI (1.15-10.54); P = 0.027]. Likewise, the GG genotype was the second most common genotype in the cases compared with the controls, and was associated with preeclampsia risk [24.6% vs. 2.5%; AOR = 14.19; 95%CI (1.77-113.76); P = 0.012]. None of the LEPRc.1968G>C variant genotypes were associated with preeclampsia. The CC genotype was not detected in neither the cases nor the controls. The haplotype A-G 70.1% was the prevalent haplotype in this population, and it significantly protected against preeclampsia [OR = 0.14; 95%CI (0.09-0.23); P < 0.001]. However, the haplotype G-G 26.8% was significantly associated with preeclampsia risk [OR = 6.70; 95%CI (4.16-11.05); P < 0.001]. Both variants c.668A>G and c.1968G>C were in strong linkage disequilibrium (D' = 1, r² = 0.012).

Our data indicate that the rs1137101 (c.668A>G) variant and G-G haplotype may independently associate with the development of preeclampsia.