Study On The Relationship Between Suicide And Gene Methylation In Pediatric Bipolar Disorder

Objective:To explore the correlation between suicide and gene methylation screened by genome-wide scanning in children and adolescents with bipolar disorder.Methods :(1)A total of 45 children and adolescents with bipolar disorder were divided into suicidal ideation group(n = 41)and non-suicidal ideation group(n = 4)by Suicidal Ideation Self-rating Scale(SIOSS).The group of suicidal ideation(n = 6)and the group non-suicidal ideation(n = 4)were selected for pre-experiment.The whole blood of 10 patients was scanned by Illumina HD 850 K microarray and the level of methylation was analyzed.The differential methylation sites among the sample groups were screened from the original data,and the genes related to suicide were screened out.(2)45 children and adolescents with bipolar disorder were divided into low-risk group(n = 12)and middle-high-risk group(n = 33)by Suicide Risk Global Assessment Scale(NGASR).The blood samples of the patients were collected,and the methylation of ABI3BP gene and DPYSL2 gene were detected by pyrophosphate sequencing and statistically analyzed.Results:(1)There was no significant difference in sex,age,education level and economic status between the suicidal ideation group and the non-suicidal ideation group(P> 0.05).(2)There was no significant difference in sex,age,education level,family history of mental illness,only child and economic situation between the low-risk group and the middle-high-risk group(P > 0.05).(3)The results of GO analysis between suicidal ideation group and non-suicidal ideation group showed that the differential methylation sites were mainly involved in the signal pathway mediated by interferon-γ,and the main signal pathways were inflammatory bowel disease(IBD)pathway,type 1 diabetes mellitus(T1DM)pathway and so on.(4)Illumina HD 850 K microarray was used to detect and screen 267 differential methylation sites between suicidal ideation group and non-suicidal ideation group.There was significant difference in methylation of ABI3BP,HLA-DQB1,HLA-DRB1,AUTS2,SP3,NINJ2,DPYSL2 and other genes between suicidal ideation group and non-suicidal ideation group.(5)There was a statistically significant difference in gene methylation levels between the suicidal ideation group and the non-suicidal ideation group(F=35.046,P=0.000<0.05).(6)There was no significant difference in the methylation degree of ABI3BP gene and DPYSL2 gene between the low suicide risk group and the middle and high suicide risk group(ABI3BP gene: t=0.706,P >0.05;DPYSL2,t=0.450,P > 0.05),and there was no significant difference in the methylation degree of DPYSL2 gene between the low-risk group and the middle-high-risk group.Conclusion:(1)Suicide ideation is associated with methylation levels of differentially methylated genes in pediatric bipolar disorder.(2)There is no significant correlation between the middle-high-risk of suicide and the methylation degree of ABI3BP gene and DPYSL2 gene in pediatric bipolar disorder.