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

- The genotypes and allele frequency distribution of 29T→C and 74G→C SNPs showed no significant differences between PE and controls in Iranian women.
- Both genotypes and allele frequencies of 788C→T (Thr 263 Ile) were significantly different between PE and control pregnant.
- Comparison of serum level of TGF-β1 in PE patients and healthy control, indicated that serum levels of this cytokine were increased significantly in PE cases.

ObjectivesPre-eclampsia (PE) is a disorder of pregnancy characterized by high blood pressure and proteinuria. Transforming growth factor beta-1 (TGF-β1) is an important replicated PE candidate gene, and few studies have evaluated the direct association of TGF-β polymorphisms and risk to PE. The aim of this study was to investigate the association between three SNPs of TGF-β1 and serum level of this cytokine in PE patients and controls.Design and methodsIn this study the polymorphisms of the TGF-β1 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-β1 was determined by enzyme-linked immunosorbent assay (ELISA) technique.ResultsAt positions 74G→C and 29T→C the genotypes and allele frequencies showed no significant differences between PE patients and normal controls (P = 0.3 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-β1 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).ConclusionsThe results of this study suggest that TGF-β1 gene 788C→T polymorphism is an important factor mediating the casual pathway of preeclampsia.