Association Between The SLC1A1 Glutamate Transporter Gene And Obsessive-compulsive Disorder In The Chinese Han Population

Objective: To explore the association between the SLC1A1 glutamate transporter gene and Obsessive-compulsive disorder in the Chinese Han population.Methods: A total of 438 OCD patients and 465 controls from the Affiliated Hospital of Medical College Qingdao University participated in this study.We diagnosed patients according to the criteria of the Diagnostic and Statistical Manual of mental disorders(DSM-IV)and assessed disease severity using the Yale-Brown Obsessive Compulsive Scale.Genomic DNA was extracted from leukocytes in the peripheral blood via standard methods.DNA amplification was then conducted using polymerase chain reaction(PCR).Following purification,the reaction product was analyzed using MassARRAY SpectroCHIP(Sequenom,San Diego,CA).SNPs were detected with a MassARRAY Compact Analyzer(Sequenom).Results were analyzed using TYPER software(Sequenom)and genotyping data were obtained.SNP genotyping was performed at Shanghai Benegene Biotechnologies Co.Ltd.,and data analysis was conducted using SPSS software(version 17.0 for Windows;SPSS,Inc.,Chicago,IL,USA).Results:No deviation of the Hardy-Weinberg equilibrium was found in the distribution of the four SNPs among OCD and control groups(P>0.05).We found significant differences in genotype frequencies of rs301434 between all OCD and control groups,while there were significant differences in genotype frequency of rs301434 between earlyonset OCD and control groups,late-onset OCD and control groups as well as male OCD and control groups(total ?~2=9.948,P=0.007;male ?~2=8.766,P=0.013;early-onset ?~2=8.982,P=0.011;late-onset ?~2=8.839,P=0.012).We also found that genotype and allele frequencies of rs3780412 were statistically significant for the late-onset OCD and control groups(genotype ?~2=7.196,P=0.027;allele ?~2=5.575,P=0.018).However,the genotype and allele frequencies of rs10491734 and rs3087879 were not statistically significant for OCD or control groups.Four loci haplotypes(rs10491734-rs3780412-rs301434-rs3087879)were found to be associated with OCD.Haplotypes SNP1-2-3-4(G-A-A-G and G-G-A-G)were statistically significant for all OCD and control groups(P=0.033 and 0.030,respectively).Haplotype SNP1-2-3-4(G-A-G-G)was associated with the male OCD group(P=0.010),while SNP1-2-3-4(G-G-A-G)was associated with the female OCD group(P=0.039).Finally,we found that SNP1-2-3-4(G-A-A-G,G-G-A-G)were associated with the late-onset OCD groups(P=0.019 and 0.024,respectively).In addition,our use of haplotype analysis showed that G-A-G-G is a risk factor for male OCD(OR = 1.737,95% CI: 1.134-2.660),while G-GA-G is a risk factor for total(OR = 1.412,95% CI: 1.033-1.930),female(OR = 1.670,95% CI: 1.021-2.730)and late-onset OCD(OR = 1.552,95% CI: 1.055-2.283).Conclusion: The polymorphisms of the rs301434 and rs3780412 in the SLC1A1 and the haplotypes G-A-A-G,G-G-A-G,and G-A-G-G are associated with the OCD in the Chinese Han population.Our findings support the idea that SLC1A1 is a susceptibility gene for OCD,but larger samples are needed to verify this result.