| 1 | Am. J. Med. Genet. B Neuropsychiatr. Genet. 2009 Apr 150B: 335-40 |
|---|
| PMID | 18561261 |
| Title | The TGM2 gene is associated with schizophrenia in a British population. |
| Abstract | Several lines of evidence have suggested an interesting link between gluten ingestion and schizophrenia. Increased levels of gliadin antibodies have been observed in patients with schizophrenia. Tissue transglutaminase (transglutaminase 2, TGM2) is involved in the production of gliadin antibodies. To investigate genetic association of the TGM2 gene with schizophrenia, we detected eight single nucleotide polymorphisms (SNPs) present in the gene among 131 family trios composed of fathers, mothers and affected offspring with schizophrenia. Data analysis with the UNPHASED program showed allelic association for rs2076380 (chi(2) = 5.51, P = 0.019), rs7270785 (chi(2) = 8.13, P = 0.004), rs4811528 (chi(2) = 6.13, P = 0.013) and rs6023526 (chi(2) = 6.13, P = 0.013). The global P-value was 0.029 for 10,000 permutations with the TDT analysis. The strongest association was observed for the rs7270785-rs4811528 haplotypes (chi(2) = 16.18, df = 3, P = 0.001), and the global P-value was 0.008 for 10,000 permutations with the 2-SNP haplotype analysis. The 8-SNP haplotype analysis also revealed a strong haplotypic association (chi(2) = 44.82, df = 18, P = 0.0004) and the 1-df test showed that the A-T-A-A-T-G-A-G haplotype was excessively transmitted (chi(2) = 16.98, corrected P = 0.0007). The present results suggest that the TGM2 gene may be involved in the development of schizophrenia. |
| SCZ Keywords | schizophrenia |
| 2 | J. Neuroimmunol. 2011 Mar 232: 5-7 |
|---|
| PMID | 20926141 |
| Title | The functional significance of the TGM2 gene in schizophrenia: a correlation of SNPs and circulating IL-2 levels. |
| Abstract | The present study was undertaken to genotype four single nucleotide polymorphisms, which were previously found to be associated with schizophrenia, in 77 patients with schizophrenia and 52 control subjects in order to assess their genotypic association with plasma IL-2 levels. Kruskal-Wallis analysis revealed an association between rs4811528 and plasma IL-2 levels in the patient group (?(2)=7.60, df=2, p=0.022) but not in the control group; binary logistic regression also confirmed the association of rs4811528 with altered IL-2 secretion (?(2)=8.191, df=3, p=0.042) after adjustment for age and sex. TGM2 may be involved in dysfunction of the immune system in schizophrenia. |
| SCZ Keywords | schizophrenia |
| 3 | Schizophr Bull 2012 May 38: 514-8 |
|---|
| PMID | 20884755 |
| Title | A study of circulating gliadin antibodies in schizophrenia among a Chinese population. |
| Abstract | The present work measured circulating antibodies against native gliadins, deamidated gliadin-derived epitopes, and transglutaminase 2 (TGM2) in 473 patients with schizophrenia and 478 control subjects among a Chinese population. The results showed that 27.1% of patients with schizophrenia were positive for the IgA antibody against native gliadins compared with 17.8% of control subjects (?(2) = 11.52, P = .0007, OR = 1.72, 95% CI 1.25-2.35), although this significant difference appeared to be due mainly to low IgA gliadin antibody levels in female controls. A total of 27.6% of female patients were positive for IgA gliadin antibodies compared with 13.9% of female controls (?(2) = 10.46, P = .0012, OR = 2.36, 95% CI 1.39-4.01), and 26.4% of male patients were positive for IgA antibodies compared with 19.8% of male controls (?(2) = 3.26, P = .071, OR = 1.46, 95% CI 0.97-2.19). Of 128 patients who were positive for the IgA antibody against native gliadins, 8 were positive for the IgA antibody against deamidated gliadin epitopes and 1 was positive for IgA anti-TGM2 antibody. However, quantitative analysis demonstrated that the mean levels of IgA antibodies against deamidated gliadin epitopes and TGM2 were significantly lower in patients with schizophrenia than the control subjects (P < .001 and P = .008, respectively). The prevalence of IgG antibodies against native gliadins was not significantly different between the patient group and the control group (?(2) = 2.25, P = .134, OR = 1.32, 95% CI 0.92-1.88). This study suggests that specific gliadin-derived epitopes may be involved in schizophrenia. |
| SCZ Keywords | schizophrenia |
| 4 | Psychiatr. Genet. 2015 Dec 25: 259-62 |
|---|
| PMID | 26307914 |
| Title | Lack of genetic association of the TGM2 gene with schizophrenia in a Chinese population. |
| Abstract | The gene coding for transglutaminase 2 (TGM2) has been reported to be associated with schizophrenia in a White population. The present study was then designed to replicate this initial finding in a Chinese population. A total of 428 individuals with schizophrenia and 555 control participants were recruited for genetic analysis. Four single nucleotide polymorphisms present in the TGM2 gene were selected for genotyping, including rs2076380, rs7270785, rs4811528, and rs6023526, by PCR-based restriction fragment length polymorphism analysis. None of these four single nucleotide polymorphisms genotyped showed an association with schizophrenia, although these 428 cases and 555 controls had 97% power to detect a disease association in small effect size (odds ratio=1.5). The present results did not support the TGM2 association with schizophrenia. It is thus possible that the TGM2 finding may have resulted from a random error of sampling. |
| SCZ Keywords | schizophrenia |