Transforming growth factor beta-1 (TGF-β1) gene single nucleotide polymorphisms (SNPs) and susceptibility to pre-eclampsia in Iranian women: A case-control study

Objectives: Pre-eclampsia (PE) is a disorder of pregnancy characterized by high blood pressure and proteinuria. Transforming growth factor beta-1 (TGF-beta 1) is an important replicated PE candidate gene, and few studies have evaluated the direct association of TGF-beta polymorphisms and risk to PE. The aim of this study was to investigate the association between three SNPs of TGF-beta 1 and serum level of this cytokine in PE patients and controls. Design and methods: In this study the polymorphisms of the TGF-beta 1 gene at the coding region, and positions 29T -> C (Leu 10 Pro), 74G -> C (Arg 25 Pro) and 788C -> T (Thr 263 Ile) were studied in 123 PE and 120 normal subjects using PCR-restriction fragment length polymorphism PCR-(RFLP) and amplification refractory mutation system (ARMS)-PCR methods. Moreover, serum TGF-beta 1 was determined by enzyme-linked immunosorbent assay (ELISA) technique. Results: At positions 74G -> C and 29T -> C the genotypes and allele frequencies showed no significant differences between PE patients and normal controls (P = 03 and P = 0.5 respectively). While in the case of position 788C -> T both genotypes and allele frequencies were significantly different between PE patients and controls (P = 0.02). Haplotype analysis on three polymorphic sites showed no significant differences between PE and control individuals (P = 0.8). TGC and CGC haplotypes were the most frequent in both studied groups. The mean serum TGF-beta 1 level was significantly higher (62.73 ng/ml) in PE patients compared with pregnant (47.01 ng/ml) and non-pregnant (40.68 ng/ml) control groups (P = 0.0001). Conclusions: The results of this study suggest that TGF-beta 1 gene 788C -> T polymorphism is an important factor mediating the casual pathway of preeclampsia. (C) 2015 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.