title: IFNGR2 genetic polymorphism associated with sex-specific paranoid schizophrenia risk.
abstract: BACKGROUND
  Considering current scientific evidence about the significant role of chronic low grade inflammation in the physiopathology of schizophrenia, it has been hypothesized that changes in pro-inflammatory cytokines such as interferon gamma may have a significant role in the predisposition to schizophrenia.
  
  
  OBJECTIVE
  This study focuses on identifying whether the functional polymorphism of interferon gamma receptor 2 (IFNGR2) is a risk factor for the development of schizophrenia.
  
  
  METHODS
  This study was conducted by the RFLP-PCR on a Tunisian population composed of 225 patients with different sub-types of schizophrenia and 166 controls.
  
  
  RESULTS
  The IFNGR2 (Q64R) polymorphism analysis showed higher frequencies of minor homozygous genotype (RR) and allele (R) in all patients compared to controls (21.8% vs 10.2%; p = .006, OR = 2.54) and (44% vs 34.9%; p = .01; OR = 1.46), respectively. This correlation was confirmed only for males. This study also noted a significant increase of the mutated homozygous (RR) genotype and (R) allele frequencies of IFNGR2 in paranoid schizophrenics compared to controls (31.4% vs 10.2%; p = .001; OR = 3.34 and 47.2% vs 34.9%; p = .009; OR = 1.66, respectively). This increase remains significant after using binary logistic regression to eliminate confounding factors such as age and sex. Additionally, carriers of RR genotype have significant lower scores on the Scale of Assessment of Positive (SAPS) and negative (SANS) symptoms comparatively to the carrier of the QQ + QR genotypes, suggesting that the R recessive allele carriers could have milder symptoms.
  
  
  CONCLUSIONS
  The IFNGR2Q64R polymorphism is correlated with male sex and paranoid schizophrenia. It is suggested that a chronic neuroinflammation may predispose to the paranoid schizophrenia development in men.
authors: a Laboratory of Genetics, Biodiversity and Valorization of Bio-Resources , Higher Institute of Biotechnology of Monastir, University of Monastir , Monastir , Tunisia.
authors: Achraf
authors: A
authors: Jemli
authors: a Laboratory of Genetics, Biodiversity and Valorization of Bio-Resources , Higher Institute of Biotechnology of Monastir, University of Monastir , Monastir , Tunisia.
authors: Oumaima
authors: O
authors: Inoubli
authors: b Department of Biostatistics , Higher Institute of Biotechnology of Monastir, University of Monastir , Monastir , Tunisia.|c Laboratory of Biomass Valorization and Production of Eucaryotic Proteins , Center of Biotechnology of Sfax , Sfax , Tunisia.
authors: Fatma
authors: F
authors: Trifa
authors: d Laboratory of Psychiatry and Vulnerability to Psychoses - CHU Fatouma Bourguiba Monastir , University of Monastir , Monastir , Tunisia.
authors: Anouar
authors: A
authors: Mechri
authors: d Laboratory of Psychiatry and Vulnerability to Psychoses - CHU Fatouma Bourguiba Monastir , University of Monastir , Monastir , Tunisia.
authors: Ferid
authors: F
authors: Zaafrane
authors: d Laboratory of Psychiatry and Vulnerability to Psychoses - CHU Fatouma Bourguiba Monastir , University of Monastir , Monastir , Tunisia.
authors: Lotfi
authors: L
authors: Gaha
authors: a Laboratory of Genetics, Biodiversity and Valorization of Bio-Resources , Higher Institute of Biotechnology of Monastir, University of Monastir , Monastir , Tunisia.
authors: Besma Bel Hadj
authors: BB
authors: Jrad
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D017471:Receptors, Interferon / Q000235:genetics*; D012559:Schizophrenia / Q000145:classification / Q000235:genetics*; D012563:Schizophrenia, Paranoid / Q000235:genetics*; D014416:Tunisia
chemical_list: C086185:IFNGR2 protein, human; D017471:Receptors, Interferon
keywords: IFNGR2; behavioural disorders; genetic polymorphism; male sex; paranoid schizophrenia; pro-inflammatory cytokine