title: Association of functional genetic variants of CTLA4 with reduced serum CTLA4 protein levels and increased risk of idiopathic recurrent miscarriages.
abstract: OBJECTIVE
  To determine whether idiopathic recurrent miscarriages (IRM) are associated with the alteration in serum CTLA4 protein levels and to evaluate their correlation with CTLA4 tag single-nucleotide polymorphisms (SNPs).
  
  
  METHODS
  Retrospective case-control study.
  
  
  METHODS
  Tertiary-care referral hospital.
  
  
  METHODS
  Three hundred women with IRM (mean age: 28.6 ± 5.4 years) and 600 age-matched (mean age: 29.2 ± 6.8) control women.
  
  
  METHODS
  Detection of genetic variants of CTLA4 markers rs231775, rs5742909, rs11571317, rs16840252, rs4553808, and rs3087243 by polymerase chain reaction followed by restriction fragment length polymorphism analysis and validated through DNA sequencing, and CTLA4 serum levels measured by enzyme-linked immunosorbent assay.
  
  
  METHODS
  Serum CTLA4 levels, genotypes, and haplotype frequencies compared in IRM cases versus controls.
  
  
  RESULTS
  We observed statistically significantly higher occurrence of minor allele homozygous of rs231775 and rs3087243 tag-SNPs in IRM cases, which suggests a risk association. A statistically significantly reduced level of CTLA4 protein was seen for mutant genotypes of rs231775 and rs3087243 tag-SNPs in women with IRM, revealing a risk association. Serum CTLA4 levels were statistically significantly reduced in women with IRM as compared with the control women. The mutant haplotype carriers of six studied tag-SNPs showed 2.34-fold higher frequencies in IRM cases. In silico analyses strengthened our observations and suggested that variation in CTLA4 gene content may influence the expression of this gene and directly or indirectly influence the function of other genes in the protein-protein interaction pathway.
  
  
  CONCLUSIONS
  These results suggest an effect of CTLA4 gene variants, with reduced sCTLA4 secretion and an increased risk for IRM. Reduced CTLA4 secretion and specific CTLA4 variants may contribute to the pathogenesis of IRM.
authors.affiliation: Department of Neurology, University of California-San Francisco, San Francisco, California.
authors.forename: Maneesh Kumar
authors.initials: MK
authors.lastname: Misra
authors.affiliation: Department of Computer Science and Engineering, Shri Ramswaroop Memorial University, Barabanki, India.
authors.forename: Aditi
authors.initials: A
authors.lastname: Mishra
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
authors.forename: Shubha R
authors.initials: SR
authors.lastname: Phadke
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India. Electronic address: sur_ksha_agrawal@yahoo.co.in.
authors.forename: Suraksha
authors.initials: S
authors.lastname: Agrawal
mesh_terms: D000026:Abortion, Habitual / Q000097:blood / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology; D000328:Adult; D015415:Biomarkers / Q000097:blood; D060908:CTLA-4 Antigen / Q000097:blood* / Q000235:genetics*; D003198:Computer Simulation; D015536:Down-Regulation; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D015810:Linkage Disequilibrium; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human
keywords: CTLA4; haplotype; linkage disequilibrium; polymorphisms; recurrent miscarriage