Leptin gene (TTTC)n microsatellite polymorphism in pre-eclampsia and HELLP syndrome

Abstract

Background: Leptin plays an important role in energy homeostasis. There is polymorphism on the leptin (LEP) gene. Our aim was to compare the tetranucleotide repeat (TTTC)n polymorphism in the 3′-flanking region in the LEP gene on DNA samples from patients with pre-eclampsia (PE), hemolysis, elevated liver enzymes, and low platelet (HELLP) syndrome and healthy pregnant controls. Methods: Blood samples were collected from healthy pregnant women (n=88), patients with PE (n=79) and HELLP (n=77) syndrome. Fluorescent PCR and DNA fragment analysis was performed from the isolated DNA for the detection of (TTTC) repeats. The electrophoretograms were evaluated and patients were assigned to two groups; class I low (<190 bp) or class II high (≥190 bp) PCR fragments. Results: We observed similar distributions of the class I and class II (TTTC) alleles in the groups studied (class I allele: healthy pregnant 58.5%; severe pre-eclamptic 58.3%; HELLP syndrome 52.6%). We detected a higher frequency of the II/II genotype in HELLP syndrome patients (32.4%) compared to healthy controls (22.7%). However, the difference was not statistically significant. Conclusions: In an ethnically homogenous population, the LEP gene (TTTC) microsatellite polymorphism in the 3′-flanking region does not show a significant difference in the allele and genotype distribution in healthy pregnant, pre-eclamptic and HELLP syndrome patients. Furthermore, we recommend a new classification of the class I and class II alleles based on the distribution of the (TTTC) microsatellites. Clin Chem Lab Med 2009;47:1033–7.