Relevance of methylenetetrahydrofolate reductase gene variants C677T and A1298C with response to fluoropyrimidine-based chemotherapy in colorectal cancer: a systematic review and meta-analysis.

Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme influencing the metabolism of fluoropyrimidines. The relevance of MTHFR polymorphisms with the clinical response to fluoropyrimidine-based chemotherapy has been explored, but the results remain controversial. Thus, a meta-analysis was performed to provide a comprehensive estimate in this account. Relevant studies were identified through PubMed, Embase and Web of Science databases from inception up to May 2017. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were applied to assess the strength of association. A total of 2118 colorectal cancer patients from 21 studies were included in the meta-analysis. Overall, there was no significant association between MTHFR C677T (rs1801133) or A1298C (rs1801131) polymorphisms and the clinical response to fluoropyrimidine-based chemotherapy under all of the three genetic models (allele model, dominant model, and recessive model) and stratification analysis, except for the retrospective study subgroup in the dominant model of MTHFR C677T and the "5-Fu + FA" treatment group in the allele contrast of MTHFR A1298C. No or moderate heterogeneity was observed in all genetic models. This meta-analysis suggested that MTHFR polymorphisms could not be considered as reliable factors for predicting the clinical response to fluoropyrimidine-based chemotherapy in colorectal cancer patients.

A case-control association study between the GRID1 gene and schizophrenia in the Chinese Northern Han population.

The glutamatergic dysfunction hypothesis of schizophrenia implicates the genes involved in glutamatergic transmission as strong candidates for schizophrenia-susceptibility. Recent linkage and association studies have identified the glutamate receptor, ionotropic, delta 1 gene GRID1 on 10q22 as a strong candidate for schizophrenia. In this current association study, we genotyped five genetic variants within the GRID1 gene in 567 Chinese Han subjects recruited from Northeast of China (260 schizophrenics and 307 normal controls). Four SNPs, rs1902666 (P=0.024), rs2814351 (P=0.027), rs11591408 (P=0.0000107) and rs999383 (P=0.000093) were found to be significantly associated with schizophrenia. Haplotype analysis also revealed significance with global P values of 0.0081 and 0.00076 for SNPs 1-2 and SNPs 3-4-5 haplotypes, respectively. Our results strongly support previously reported association studies, implicating GRID1 in the etiology of schizophrenia.

[Transmission disequilibrium test of polymorphisms of serotonin transporter gene and schizophrenia based on family trios].

OBJECTIVE: To investigate the relationship between two polymorphisms (Intronic VNTR and 5-HTTLPR) of the serotonin transporter gene and schizophrenia. METHODS: A set of 314 schizophrenic trio samples collected from Shanghai, Xi'an and Jilin regions of China independently was subjected to analysis of the polymorphisms by transmission/disequilibrium test(TDT). RESULTS: No significantly preferential transmission of any allele was detected from both polymorphisms investigated. CONCLUSION: The results suggest that the serotonin transporter gene is unlikely to have a major contribution to susceptibility to schizophrenia in Han Chinese population.