Unburdened by false humility, postmodern trauma activists claim to have understood for the first time what drives all of human suffering
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CATEGORY: CONTROL OF LANGUAGE AND IDEAS  Genetics researcher Nathan Wellington, PhD Source: Journal of Neurogenetics Read time: 2.3 minutes This Happened In September 2024, a review of epigenetic research related to posttraumatic stress disorder (PTSD) was published. Past reviews focused primarily on DNA methylation. This review included factors that regulate methylation including histones, microRNA, and single nucleotide polymorphisms (SNPs). Who Did This The first author was Nathan Wellington, PhD, a postdoc fellow at University of the Sunshine Coast, Australia. This is his first first-author publication. He has one secondary author publication. His career aim is to develop genetic biomarkers of PTSD to provide treatment targets. Background Epigenetics is the process by which gene expression is regulated. DNA contains the codes for genes, but for genes to be expressed, the DNA has to be transcribed to the gene protein product that does the actual work in the body. Most studies have focused on methylation, which is either adding methyl groups or removing methyl groups on DNA. It is believed that adding methyl groups usually blocks gene expression. Some SNPs can influence methylation. A gene can exist in many variants (SNPs) that differ by a single nucleotide in a key region that alters the function of the gene. MicroRNA (miRNA) are small, single-stranded RNA that can bind to RNA and block gene expression. Histones are protein structures that act as spools around which DNA winds itself. Histones protect DNA from damage and facilitate DNA being coded into gene products. The Claim One purpose of investigating epigenetics is to try to identify biomarkers, which can be used to either detect individuals who will be susceptible to develop PTSD if they experience trauma, or to accurately detect individuals who have PTSD. Methylation Seventy-three studies investigated DNA methylation, identifying 488 unique DNA sites that were hypomethylated, and 1,940 sites that were hypermethylated in individuals with PTSD. Replications between studies were rare; among hypomethylated sites, only five were found more than once (i.e., replicated); among hypermethylated sites, only 20 were found more than once. No site was found in more than three of the 73 studies. SNPs Nineteen studies investigated SNPs, identifying 88 SNPs related to PTSD. Only one SNP finding was replicated, being found in three studies. miRNA Sixteen studies investigated miRNAs, identifying 194 downregulated and 24 upregulated miRNAs that were replicated in at least two studies. Three studies dominated, accounting for 87% of these replications. The other thirteen studies accounted for 13% of the replications. Histones Nine studies examined alterations on histones. No sites have been replicated. Analysis
Third, the findings do not show a reasonable promise of being replicable, as this literature review demonstrated. While the authors of the review appeared to believe that 20 hypermethylated sites replicated in two of 73 studies was reason for hope, that is the same thing researchers on psychophysiology and brain imaging asserted for years before fading away. No patient's treatment has ever been influenced by epigenetic data. Should these types of studies continue anyway? Perhaps in the hope that some new breakthrough will make sense of it all? With research funding limited, this is a question that the National Institute of Mental Health has been historically slow to grapple with partially because admitting defeat would diminish the enthusiasm for research funding. Comments are closed.
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