Association of the IFN-γ (+874A/T) Genetic Polymorphism with Paranoid Schizophrenia in Tunisian Population.
Since growing evidence suggests a significant role of chronic low-grade inflammation in the physiopathology of schizophrenia, we have hypothesized that functional genetic variant of the IFN gamma (IFN-γ; +874A/T; rs2430561) gene may be involved in the predisposition to schizophrenia. This research is based on a case-control study which aims to identify whether polymorphism of the IFN-γ gene is a risk factor for the development of schizophrenia. The RFLP-PCR genotyping of the IFN-γ gene was conducted on a Tunisian population composed of 218 patients and 162 controls. The IFN-γ (+874A/T) polymorphism analysis showed higher frequencies of minor homozygous genotype (TT) and allele (T) in all patients compared with controls (11.5 vs. 4.9%; p = 0.03, OR = 2.64 and 30.7 vs. 24.1%, p = 0.04, OR = 1.4, respectively). This correlation was confirmed for male but not for female patients. Also, the T allele was significantly more common among patients with paranoid schizophrenia when compared with controls (25.8 vs. 4.9%, p = 0.0001; OR = 6.7). Using the binary regression analysis to eliminate confounding factors as age and sex, only this last association remained significant (p = 0.03; OR = 1.76, CI = 1.05-2.93). In conclusion, our results showed a significant association between +874A/T polymorphism of IFN-γ and paranoid schizophrenia, suggesting that this single nucleotide polymorphism (SNP) or another at proximity could predispose to paranoid schizophrenia. Since the minor allele of this polymorphism was correlated with an increased expression of their product, our study validates the hypothesis of excessive pro-inflammatory cytokine in the physiopathology of paranoid schizophrenia.
a Laboratory of Genetics, Biodiversity and Bioresource Valorization, Higher Institute of Biotechnology of Monastir , University of Monastir , Monastir , Tunisia.
Achraf
A
Jemli
a Laboratory of Genetics, Biodiversity and Bioresource Valorization, Higher Institute of Biotechnology of Monastir , University of Monastir , Monastir , Tunisia.
Awatef
A
Eshili
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.
Fatma
F
Trifa
d Department of Psychiatry and Vulnerability to Psychoses Laboratory - CHU Monastir , University of Monastir , Monastir , Tunisia.
Anouar
A
Mechri
d Department of Psychiatry and Vulnerability to Psychoses Laboratory - CHU Monastir , University of Monastir , Monastir , Tunisia.
Ferid
F
Zaafrane
d Department of Psychiatry and Vulnerability to Psychoses Laboratory - CHU Monastir , University of Monastir , Monastir , Tunisia.
Lotfi
L
Gaha
e Department of Psychiatry and Psychotherapy , Ruhr University, Bochum LWL University Hospital Bochum , Bochum , Germany.
George
G
Juckel
a Laboratory of Genetics, Biodiversity and Bioresource Valorization, Higher Institute of Biotechnology of Monastir , University of Monastir , Monastir , Tunisia.
Besma Bel Hadj Jrad
BB
Tensaout
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007249:Inflammation / Q000235:genetics*; D007371:Interferon-gamma / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D012563:Schizophrenia, Paranoid / Q000235:genetics*; D014416:Tunisia; D055815:Young Adult
D007371:Interferon-gamma
Behavioral disorders; IFN-γ; genetic polymorphism; paranoid subtype; proinflammatory cytokine; schizophrenia