title: Polymorphisms of endocrine gland-derived vascular endothelial growth factor gene and its receptor genes are associated with recurrent pregnancy loss.
abstract: BACKGROUND
  Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) and its receptor genes [prokineticin receptor 1 (PKR1) and prokineticin receptor 2 (PKR2)] have been identified in the last decade and their expression is restricted to the steroidogenic glands (ovary, testis, adrenal gland and placenta). Their expression patterns also suggest a close relationship to early pregnancy. However, little information is available regarding the role of EG-VEGF and its receptors (PKR1 and PKR2) in recurrent pregnancy loss (RPL). This study was conducted to investigate the association between polymorphisms of EG-VEGF and its receptor genes (PKR1 and PKR2) and idiopathic RPL.
  
  
  METHODS
  In this case-control study, 115 women with a history of idiopathic RPL and 170 controls were included. A total of 11 tag single nucleotide polymorphisms (SNPs) selected from EG-VEGF, PKR1 and PKR2 were genotyped. We further used multifactor dimensionality reduction (MDR) analysis to choose a best model and evaluate gene-gene interactions.
  
  
  RESULTS
  Two tag SNPs of PKR1 (rs4627609, rs6731838) and one tag SNP of PKR2 (rs6053283) were significantly associated with idiopathic RPL (P < 0.05). The frequencies of haplotypes C-G and T-A of PKR1 and haplotype A-G-C-G-G of PKR2 were significantly increased in women with idiopathic RPL (P < 0.05); MDR tests revealed gene-gene interactions between three loci [EG-VEGF (rs7513898), PKR1(rs6731838), PKR2(rs6053283)] based on the association model (P = 0.008). The adjusted odds ratio of high- and low-risk genotype combinations in the three-locus model was 3.94 (95% confidence interval: 2.38-6.52).
  
  
  CONCLUSIONS
  EG-VEGF receptor (PKR1, PKR2) gene polymorphisms and haplotypes were associated with idiopathic RPL. These three genes (EG-VEGF, PKR1 and PRK2) jointly contribute to RPL in the Taiwanese Han population.
authors.affiliation: Division of Genetics, Department of Obstetrics and Gynecology, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Mei-Tsz
authors.initials: MT
authors.lastname: Su
authors.forename: Sheng-Hsiang
authors.initials: SH
authors.lastname: Lin
authors.forename: I-Wen
authors.initials: IW
authors.lastname: Lee
authors.forename: Yi-Chi
authors.initials: YC
authors.lastname: Chen
authors.forename: Chao-Chin
authors.initials: CC
authors.lastname: Hsu
authors.forename: Hsien-An
authors.initials: HA
authors.lastname: Pan
authors.forename: Pao-Lin
authors.initials: PL
authors.lastname: Kuo
mesh_terms: D000026:Abortion, Habitual / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D043562:Receptors, G-Protein-Coupled / Q000235:genetics*; D018000:Receptors, Peptide / Q000235:genetics*; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived / Q000235:genetics*
chemical_list: C470837:PROKR1 protein, human; C470838:PROKR2 protein, human; D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived