scholarly journals Genomic Imprinting

2016 ◽  
Vol 4 (1) ◽  
pp. 181-184 ◽  
Author(s):  
Emirjeta Bajrami ◽  
Mirko Spiroski
Keyword(s):  
Gene Expression ◽  
Autism Spectrum Disorder ◽  
Dna Methylation ◽  
Genomic Imprinting ◽  
Environmental Influence ◽  
Autism Spectrum ◽  
Chromosome 15 ◽  
Prader Willi Syndrome ◽  
Epigenetic Mechanisms ◽  
Active Allele

BACKGROUND: Genomic imprinting is the inheritance out of Mendelian borders. Many of inherited diseases and human development violates Mendelian law of inheritance, this way of inheriting is studied by epigenetics.AIM: The aim of this review is to analyze current opinions and options regarding to this way of inheriting.RESULTS: Epigenetics shows that gene expression undergoes changes more complex than modifications in the DNA sequence; it includes the environmental influence on the gametes before conception. Humans inherit two alleles from mother and father, both are functional for the majority of the genes, but sometimes one is turned off or “stamped” and doesn’t show in offspring, that gene is imprinted. Imprinting means that that gene is silenced, and gene from other parent is expressed. The mechanisms for imprinting are still incompletely defined, but they involve epigenetic modifications that are erased and then reset during the creation of eggs and sperm. Genomic imprinting is a process of silencing genes through DNA methylation. The repressed allele is methylated, while the active allele is unmethylated. The most well-known conditions include Prader-Willi syndrome, and Angelman syndrome. Both of these syndromes can be caused by imprinting or other errors involving genes on the long arm of chromosome 15.CONCLUSIONS: Genomic imprinting and other epigenetic mechanisms such as environment is shown that plays role in offspring neurodevelopment and autism spectrum disorder.

scholarly journals DNA Methylation of PGC-1α Is Associated With Elevated mtDNA Copy Number and Altered Urinary Metabolites in Autism Spectrum Disorder

2021 ◽  
Vol 9 ◽  
Author(s):  
Sophia Bam ◽  
Erin Buchanan ◽  
Caitlyn Mahony ◽  
Colleen O’Ryan
Keyword(s):  
Autism Spectrum Disorder ◽  
Dna Methylation ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Function ◽  
Copy Number ◽  
Autism Spectrum ◽  
Differential Methylation ◽  
Mtdna Copy Number ◽  
Key Genes

Autism spectrum disorder (ASD) is a complex disorder that is underpinned by numerous dysregulated biological pathways, including pathways that affect mitochondrial function. Epigenetic mechanisms contribute to this dysregulation and DNA methylation is an important factor in the etiology of ASD. We measured DNA methylation of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α), as well as five genes involved in regulating mitochondrial homeostasis to examine mitochondrial dysfunction in an ASD cohort of South African children. Using targeted Next Generation bisulfite sequencing, we found differential methylation (p < 0.05) at six key genes converging on mitochondrial biogenesis, fission and fusion in ASD, namely PGC-1α, STOML2, MFN2, FIS1, OPA1, and GABPA. PGC-1α, the transcriptional regulator of biogenesis, was significantly hypermethylated at eight CpG sites in the gene promoter, one of which contained a putative binding site for CAMP response binding element 1 (CREB1) (p = 1 × 10–6). Mitochondrial DNA (mtDNA) copy number, a marker of mitochondrial function, was elevated (p = 0.002) in ASD compared to controls and correlated significantly with DNA methylation at the PGC-1α promoter and there was a positive correlation between methylation at PGC-1α CpG#1 and mtDNA copy number (Spearman’s r = 0.2, n = 49, p = 0.04) in ASD. Furthermore, DNA methylation at PGC-1α CpG#1 and mtDNA copy number correlated significantly (p < 0.05) with levels of urinary organic acids associated with mitochondrial dysfunction, oxidative stress, and neuroendocrinology. Our data show differential methylation in ASD at six key genes converging on PGC-1α-dependent regulation of mitochondrial biogenesis and function. We demonstrate that methylation at the PGC-1α promoter is associated with elevated mtDNA copy number and metabolomic evidence of mitochondrial dysfunction in ASD. This highlights an unexplored role for DNA methylation in regulating specific pathways involved in mitochondrial biogenesis, fission and fusion contributing to mitochondrial dysfunction in ASD.

scholarly journals LINE-1 and Alu methylation Signatures in Autism Spectrum Disorder and Their Function in The Regulation of Autism-Related Genes

2021 ◽  
Author(s):  
Thanit Saeliw ◽  
Tiravut Permpoon ◽  
Nutta Iadsee ◽  
Tewin Tencomnao ◽  
Tewarit Sarachana ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Dna Methylation ◽  
Autism Spectrum ◽  
Small Sample ◽  
Spectrum Disorder ◽  
Post Mortem ◽  
Global Methylation ◽  
Post Mortem Brain ◽  
Dna Methylation Profiling ◽  
Methylation Profiling

Abstract BackgroundLong interspersed nucleotide element-1 (LINE-1) and Alu elements are retrotransposons whose abilities cause abnormal gene expression and genomic instability. Several studies have focused on DNA methylation profiling of gene regions, but the locus-specific methylation of LINE-1 and Alu elements has not been identified in autism spectrum disorder (ASD).MethodsHere, DNA methylation age was predicted using Horvath’s method. We interrogated locus- and family-specific methylation profiles of LINE-1 and Alu elements (22,352 loci) in ASD blood using publicly-available Illumina Infinium 450K methylation datasets from heterogeneous ASD (n = 52), ASD with 16p11.2 del (n = 7), and ASD with Chromodomain Helicase DNA-binding 8 (CHD8) variants (n = 15). The differentially methylated positions of LINE-1 and Alu elements corresponding to genes were combined with transcriptome data from multiple ASD studies. ROC curve was conducted to examine the specificity of target loci.ResultsEpigenetic age acceleration was significantly decelerated in ASD children over the age of 11 years. DNA methylation profiling revealed LINE-1 and Alu methylation signatures in each ASD risk loci by which global methylation were notably hypomethylated exclusively in ASD with CHD8 variants. When LINE-1 and Alu elements were clustered into subfamilies, we found methylation changes in a family-specific manner in L1P, L1H, HAL, AluJ, and AluS families in the heterogeneous ASD and ASD with CHD8 variants. Our results showed that LINE-1 and Alu methylation within target genes is inversely related to the expression level in each ASD variant. Moreover, LINE-1 and Alu methylation signatures can be used to predict ASD individuals from non-ASD.LimitationsIntegration of methylome and transcriptome datasets was performed from different ASD cohorts. The small sample size of the validation cohort used post-mortem brain tissues and necessitates future validation in a larger cohort.ConclusionsThe DNA methylation signatures of the LINE-1 and Alu elements in ASD, as well as their functional impact on ASD-related genes, have been studied. These findings are considered for further research into DNA methylation profiles and the expression of the LINE-1 and Alu elements in post-mortem brain tissue, which has been linked to ASD pathogenesis.

The epigenetic regulation of synaptic genes contributes to the etiology of autism

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Annamaria Srancikova ◽  
Zuzana Bacova ◽  
Jan Bakos
Keyword(s):  
Epigenetic Regulation ◽  
Neurodevelopmental Disorders ◽  
Autism Spectrum ◽  
Prader Willi Syndrome ◽  
Epigenetic Mechanisms ◽  
Substantial Evidence ◽  
Autistic Symptoms ◽  
Spectrum Disorders ◽  
The Brain

Abstract Epigenetic mechanisms greatly affect the developing brain, as well as the maturation of synapses with pervasive, long-lasting consequences on behavior in adults. Substantial evidence exists that implicates dysregulation of epigenetic mechanisms in the etiology of neurodevelopmental disorders. Therefore, this review explains the role of enzymes involved in DNA methylation and demethylation in neurodevelopment by emphasizing changes of synaptic genes and proteins. Epigenetic causes of sex-dependent differences in the brain are analyzed in conjunction with the pathophysiology of autism spectrum disorders. Special attention is devoted to the epigenetic regulation of the melanoma-associated antigen-like gene 2 (MAGEL2) found in Prader-Willi syndrome, which is known to be accompanied by autistic symptoms.

scholarly journals DNA Methylation and Susceptibility to Autism Spectrum Disorder

2019 ◽  
Vol 70 (1) ◽  
pp. 151-166 ◽  
Author(s):  
Martine W. Tremblay ◽  
Yong-hui Jiang
Keyword(s):  
Autism Spectrum Disorder ◽  
Dna Methylation ◽  
Causative Factor ◽  
Autism Spectrum ◽  
Postnatal Period ◽  
Spectrum Disorder ◽  
Regulation Of Transcription ◽  
Peak Time ◽  
Genome Wide ◽  
Technical Advances

The prevalence of autism spectrum disorder (ASD) has been increasing steadily over the last 20 years; however, the molecular basis for the majority of ASD cases remains unknown. Recent advances in next-generation sequencing and detection of DNA modifications have made methylation-dependent regulation of transcription an attractive hypothesis for being a causative factor in ASD etiology. Evidence for abnormal DNA methylation in ASD can be seen on multiple levels, from genetic mutations in epigenetic machinery to loci-specific and genome-wide changes in DNA methylation. Epimutations in DNA methylation can be acquired throughout life, as global DNA methylation reprogramming is dynamic during embryonic development and the early postnatal period that corresponds to the peak time of synaptogenesis. However, technical advances and causative evidence still need to be established before abnormal DNA methylation and ASD can be confidently associated.

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