title: Association between genetic polymorphisms of Toll-like receptor 2 (TLR2) and schizophrenia in the Korean population.
abstract: Immunological dysregulation has been suggested to be involved in the pathogenesis of schizophrenia. Accumulating evidences further implicate that activated inflammatory processes may be particularly relevant for the precipitation of negative and cognitive symptoms of schizophrenia. Toll-like receptor 2 (TLR2) plays an important role in innate immunity by sensing a variety of pathogens and inducing an acquired immunity. In the present study, we investigated whether the coding region of single nucleotide polymorphisms (SNPs) of the TLR2 gene was associated with schizophrenia as well as with clinical symptoms in schizophrenia patients. The study population consisted of 286 Korean schizophrenia patients and 305 Korean control subjects. The assessment of the Scale for the Assessment of Negative Symptoms was used to evaluate the negative symptoms of schizophrenia; the operational criteria checklist was used to measure general psychopathology. We selected two cSNPs [rs3804099 (Asn199Asn) and rs3804100 (Ser450Ser)] considering their heterozygosity and minor allele frequency. SNP genotyping was conducted using direct sequencing. We did not find any significant associations between SNPs and schizophrenia in the genotype and allelic frequencies. On the other hand, in the analysis of cognitive symptoms, rs3804099 showed significant differences in schizophrenia patients with poor concentration in the dominant model (TC/CC vs. TT, p=0.0099). Also, rs3804100 showed a significant association with poor concentration in the co-dominant (TC vs. TT, p=0.014) and the dominant models (TC/CC vs. TT, p=0.0035). We obtained no significant support for the association of the TLR2 gene with susceptibility to schizophrenia in the Korean population. However, our results provide possibility that C allele of rs3804099 and rs3804100 may be associated with poor concentration in schizophrenia patients. Further studies with larger samples are required to confirm our results.
authors: Department of Neuropsychiatry, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea.
authors: Won Sub
authors: WS
authors: Kang
authors: Jin Kyung
authors: JK
authors: Park
authors: Sang Min
authors: SM
authors: Lee
authors: Su Kang
authors: SK
authors: Kim
authors: Hae Jeong
authors: HJ
authors: Park
authors: Jong Woo
authors: JW
authors: Kim
mesh_terms: D000328:Adult; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D056910:Republic of Korea; D012559:Schizophrenia / Q000235:genetics*; D051195:Toll-Like Receptor 2 / Q000235:genetics*
chemical_list: D051195:Toll-Like Receptor 2
keywords: CI; CNS; HWE; Hardy–Weinberg equilibrium; Immunological dysregulation; LD; OPCRIT; ORs; Poor concentration; SANS; SD; SNP; Scale for the Assessment of Negative Symptoms; Schizophrenia; TLR2; TLR2 gene; TNF-α; Toll-like receptor 2; central nervous system; confidence interval; linkage disequilibrium; odds ratios; operation criteria checklist for psychotic illness; single nucleotide polymorphism; standard deviation; tumor necrosis factor-α