Interleukin-10 gene promoter polymorphism in patients with schizophrenia in a region of East Turkey

Yazan: admin Tarih: Oca 21st, 2010 | Kategori:: Gene polymorphisms, Interleukin, schizophrenia

Author(s): Ozbey U (Ozbey, Ulku)2, Tug E (Tug, Esra)1, Namli M (Namli, Mustafa)3
Source: WORLD JOURNAL OF BIOLOGICAL PSYCHIATRY Volume: 10 Issue: 5 Pages: 461-468 Published: 2009

Abstract: Schizophrenia is one of the most severe psychiatric disorders, with a worldwide incidence of 1%. Immunological abnormalities have been found to be associated with schizophrenia for decades. Cytokines are key proteins involved in the immune system activation. Interleukin-10 (IL-10), an important immunoregulatory cytokine, is located on chromosome 1q31 32, a region previously reported to be linked to schizophrenia in genetic studies. In the present study it was aimed to examine the IL-10 gene promoter region’s polymorphic variants in patients with schizophrenia in a population of the Elazig Region of East Anatolia, Turkey. Polymorphisms at position -1082, -819 and -592 in the IL-10 promoter region were determined in 171 Turkish patients who were diagnosed with schizophrenia, based on the DSM-IV, and 168 healthy controls, by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). We analyzed allele, genotype, and haplotype distributions using a case-control association study. Genotyping was performed by RFLP. Statistically significant differences were observed in both allelic and genotypic frequencies of the -592A/C polymorphism (Allele, P = 0.034, OR = 1.26, 95% CI 1.02 – 1.56; Genotype, P = 0.048), while the other two polymorphisms in distribution of the alleles and genotypes in patients with schizophrenia were not significantly different from those of controls (P > 0.05). Our results show a significant increase of GTA homozygotes (the high IL-10-producing haplotype) in schizophrenic patients compared to control subjects (P = 0.0001). These data suggest that the IL-10 gene promoter polymorphism may be one of the susceptibility factors to develop schizophrenia in the Turkish population, and apparently in all humans.
Document Type: Article
Language: English
Author Keywords: Biological psychiatry; cytokines; genetics; polymorphism; schizophrenia
KeyWords Plus: ASSOCIATION; HAPLOTYPES; POPULATION; LINKAGE
Reprint Address: Tug, E (reprint author), Abant Izzet Baysal Univ, Izzet Baysal Med Sch, Dept Med Genet, TR-14280 Bolu, Turkey
Addresses:
1. Abant Izzet Baysal Univ, Izzet Baysal Med Sch, Dept Med Genet, TR-14280 Bolu, Turkey
2. Firat Univ, Fac Med, Dept Med Biol & Genet, TR-23169 Elazig, Turkey
3. Hosp Psychiat, Elazig, Turkey
E-mail Addresses: esratug@hotmail.com


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Paraoxonase-1 55/192 genotypes in schizophrenic patients and their relatives in Turkish population.

Yazan: admin Tarih: Ara 10th, 2008 | Kategori:: Kategorilenmemiş

Psychiatr Genet. 2008 Dec;18(6):289-94

Kucukali CI, Aydin M, Ozkok E, Orhan N, Cakir U, Kilic G, Ozbek Z, Ince N, Kara I.

Istanbul Erenkoy Psychiatric and Neurological Disorders Hospital, Istanbul, Turkey. cemsmile@hotmail.com

BACKGROUND: Oxidative stress and free radical-induced toxicity have been implicated in the pathophysiology of schizophrenia. In this study, we examined paraoxonase (PON1)-55/192 polymorphisms and PON1 activity in patients with schizophrenia, first-degree relatives of schizophrenic patients, and healthy controls. METHODS: This study consisted of 292 healthy participants, 267 unrelated patients with schizophrenia and 311 first-degree relatives of schizophrenic patients. PON1 55 (rs 854560) and PON1 192 (rs 662) polymorphisms were performed by restriction fragment length polymorphism. RESULTS: The frequencies of the QQ and LL genotypes were significantly overpresented in controls compared with those of schizophrenic patients and their relatives. In contrast, the RR genotype was more prevalent in patients than their relatives and healthy controls. The frequencies of the LM and QR genotypes in relatives were higher than controls. Serum PON1 activities of controls were significantly higher when compared with both schizophrenic patients and their relatives. The RR and LL genotypes were associated with a significantly increased PON1 activity as compared with QR or QQ and MM or LM genotypes, respectively, in all groups. CONCLUSION: This is the first study that shows the association between PON1-55/192 polymorphisms and schizophrenia. Our data suggest that the subjects carrying R allele or RR genotype might be susceptible to schizophrenia and subjects with QQ or LL might be protected against schizophrenia. First-degree relatives of schizophrenic patients have higher heterozygote genotypes, suggesting that this group can shift either to patient or control group depending on their allele types and environmental factors. PON1 genetic variations are also associated with PON1 activities. Reduced PON1 activity in patients and their relatives might result from the combined effects of more than one polymorphic variant in PON1 or other genes and/or increased oxidative stress, supporting the hypothesis that reactive oxygen species-mediated cellular damage might contribute to the neuropathology of schizophrenia.


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