Micro non-coding RNA (microRNA, miRNA) is a small non-coding RNA involved in gene expression regulation that plays an important role in the onset and development of mental illness. Evidence suggests that several miRNAs are dysregulated in patients with mental illnesses. Because of its stability and quantitative detection in peripheral blood and cerebral fluid, miRNA is a particularly attractive biomarker. The objective of this research is to investigate the relationship between mental illness and miRNAs, as well as the potential processes through which miRNAs contribute to disease etiology. Schizophrenia, bipolar disorder, and depression are three major mental disorders with high disability and mortality. The study explored the particular dysregulated miRNAs for each condition as well as common dysregulated miRNAs across diseases. In this study, which analyzes the findings from relevant studies from 2016 to 2020, the authors discuss the functions of numerous severely dysfunctional miRNAs and their application potential in the field of psychiatry research.
Biomarkers ; Bipolar Disorder/genetics* ; Depression/genetics* ; Humans ; MicroRNAs ; Schizophrenia/genetics*

Bipolar Disorder ; genetics ; Genome-Wide Association Study ; Genomics ; methods ; Humans

The early growth response gene 2 (EGR2) is located at chromosome 10q21, one of the susceptibility loci in bipolar disorder (BD). EGR2 is involved in cognitive function, myelination, and signal transduction related to neuregulin-ErbB receptor, Bcl-2 family proteins, and brain-derived neurotrophic factor. This study investigated the genetic association of the EGR2 gene with BD and schizophrenia (SPR) in Korea. In 946 subjects (350 healthy controls, 352 patients with BD, and 244 with SPR), nine single nucleotide polymorphisms (SNPs) in the EGR2 gene region were genotyped. Five SNPs showed nominally significant allelic associations with BD (rs2295814, rs61865882, rs10995315, rs2297488, and rs2297489), and the positive associations of all except rs2297488 remained significant after multiple testing correction. Linkage disequilibrium structure analysis revealed two haplotype blocks. Among the common identified haplotypes (frequency > 5%), 'T-G-A-C-T (block 1)' and 'A-A-G-C (block 2)' haplotypes were over-represented, while 'C-G-G-T-T (block 1)' haplotype was under-represented in BD. In contrast, no significant associations were found with SPR. Although an extended analysis with a larger sample size or independent replication is required, these findings suggest a genetic association of EGR2 with BD. Combined with a plausible biological function of EGR2, the EGR2 gene is a possible susceptibility gene in BD.
Adult ; Bipolar Disorder/*genetics ; Early Growth Response Protein 2/*genetics ; Female ; Genetic Predisposition to Disease/genetics ; Genotype ; Haplotypes/genetics ; Humans ; Korea ; Linkage Disequilibrium/genetics ; Male ; Polymorphism, Single Nucleotide/genetics ; Schizophrenia/genetics

People called night owls habitually have late bedtimes and late times of arising, sometimes suffering a heritable circadian disturbance called delayed sleep phase syndrome (DSPS). Those with DSPS, those with more severe progressively-late non-24-hour sleep-wake cycles, and those with bipolar disorder may share genetic tendencies for slowed or delayed circadian cycles. We searched for polymorphisms associated with DSPS in a case-control study of DSPS research participants and a separate study of Sleep Center patients undergoing polysomnography. In 45 participants, we resequenced portions of 15 circadian genes to identify unknown polymorphisms that might be associated with DSPS, non-24-hour rhythms, or bipolar comorbidities. We then genotyped single nucleotide polymorphisms (SNPs) in both larger samples, using Illumina Golden Gate assays. Associations of SNPs with the DSPS phenotype and with the morningness-eveningness parametric phenotype were computed for both samples, then combined for meta-analyses. Delayed sleep and "eveningness" were inversely associated with loci in circadian genes NFIL3 (rs2482705) and RORC (rs3828057). A group of haplotypes overlapping BHLHE40 was associated with non-24-hour sleep-wake cycles, and less robustly, with delayed sleep and bipolar disorder (e.g., rs34883305, rs34870629, rs74439275, and rs3750275 were associated with n=37, p=4.58E-09, Bonferroni p=2.95E-06). Bright light and melatonin can palliate circadian disorders, and genetics may clarify the underlying circadian photoperiodic mechanisms. After further replication and identification of the causal polymorphisms, these findings may point to future treatments for DSPS, non-24-hour rhythms, and possibly bipolar disorder or depression.
Bipolar Disorder ; Case-Control Studies ; Comorbidity ; Depression ; Genetics ; Haplotypes ; Humans ; Melatonin ; Phenotype ; Photoperiod ; Polymorphism, Single Nucleotide ; Polysomnography ; Sleep Wake Disorders, Circadian Rhythm ; Strigiformes*

PURPOSE: Genetic factors are known to be important in the etiology of bipolar disorder (BD). The fragile sites (FSs) are a very interesting subject for the study of clinical disorders. The aim of this study was to evaluate fragile sites seen in patients with bipolar disorder and find a correlation between some fragile sites and bipolar disorder. PATIENTS AND METHODS: The frequencies of folate sensitive FSs were compared in short-term whole blood cultures from bipolar patients and from normal individuals. RESULTS: The rate of FS expression in the patients was considerably higher than in the controls (p < 0.001). Several chromosome regions including 1p36, 1q21, 1q32, 3p25, 7q22, 7q32, 11q23, 12q24, 13q32, 14q24, Xp22 and Xq26 were represented considerably more often in the patients than in the controls (p value between 0.001 to 0.036). Among these FSs, the sites 1p36, 1q21, 3p25, 7q22, 7q32, and 14q24 were not observed in other studies. CONCLUSION: These regions can be the most active of hot spots in the genomes of bipolar patients, and may harbor important genes associated with BD.
Adolescent ; Adult ; Bipolar Disorder/*genetics ; Chromosome Fragile Sites/drug effects/*genetics ; Chromosome Fragility/drug effects/*genetics ; Chromosomes, Human/*genetics ; Cytogenetics ; Female ; Folic Acid/pharmacology ; Genetic Predisposition to Disease ; Humans ; Male ; Middle Aged ; Young Adult

OBJECTIVETo assess the association of neural development-related genes LIS1and TSNAX with bipolar disorder in a Chinese Han population.

METHODSThree hundred and eight five patients (including 188 males and 197 females) from Guangzhou Brain Hospital with bipolar disorder meeting the Diagnostic and Statistic Manual of Bipolar Disorder (BDI) (Fourth Edition) criteria and 475 healthy controls from the local community were recruited. Ten single nucleotide polymorphisms (SNPs) of the LIS1 and TSNAX genes were genotyped by GoldenGate genotyping assay on an Illumina Beadstation 500 machine. Association analyses of SNPs and haplotypes were performed with Plink 1.07 software.

RESULTSAnalysis of the total sample has failed to find any association of SNP or haplotype of the two genes with BDI (P> 0.05). When patients were divided into subgroups with or without psychotic symptom, no significant association of the two genes was found with psychotic BDI or non-psychotic BDI (P> 0.05). No significant association was found between any SNP and haplotype of two genes and female BDI or male BDI, nor were significant association found between age of onset and LIS1 and TSNAX gene polymorphisms.

CONCLUSIONOur results indicated that LIS1 and TSNAX genes are not associated with susceptibility to bipolar I disorder in Chinese Han population.

1-Alkyl-2-acetylglycerophosphocholine Esterase ; genetics ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; ethnology ; genetics ; Bipolar Disorder ; ethnology ; genetics ; Case-Control Studies ; DNA-Binding Proteins ; genetics ; Female ; Genetic Predisposition to Disease ; Genotype ; Humans ; Male ; Microtubule-Associated Proteins ; genetics ; Middle Aged ; Polymorphism, Single Nucleotide ; Young Adult

Amyotrophic Lateral Sclerosis ; genetics ; Animals ; Biological Transport, Active ; Bipolar Disorder ; genetics ; Glucose Transporter Type 4 ; metabolism ; Hepacivirus ; physiology ; Humans ; Neoplasm Metastasis ; Neoplasms ; metabolism ; Point Mutation ; Polymorphism, Single Nucleotide ; R-SNARE Proteins ; metabolism ; Tissue Distribution ; Transport Vesicles ; physiology ; Vesicular Transport Proteins ; chemistry ; genetics ; metabolism ; physiology ; Virus Replication