1 1969 128 EPIGENETIC ALTERATIONS AND AN INCREASED FREQUENCY OF MICRONUCLEI IN WOMEN WITH FIBROMYALGIA. FIBROMYALGIA (FM), CHARACTERIZED BY CHRONIC WIDESPREAD PAIN, FATIGUE, AND COGNITIVE/MOOD DISTURBANCES, LEADS TO REDUCED WORKPLACE PRODUCTIVITY AND INCREASED HEALTHCARE EXPENSES. TO DETERMINE IF ACQUIRED EPIGENETIC/GENETIC CHANGES ARE ASSOCIATED WITH FM, WE COMPARED THE FREQUENCY OF SPONTANEOUSLY OCCURRING MICRONUCLEI (MN) AND GENOME-WIDE METHYLATION PATTERNS IN WOMEN WITH FM (N = 10) TO THOSE SEEN IN COMPARABLY AGED HEALTHY CONTROLS (N = 42 (MN); N = 8 (METHYLATION)). THE MEAN (SD) MN FREQUENCY OF WOMEN WITH FM (51.4 (21.9)) WAS SIGNIFICANTLY HIGHER THAN THAT OF CONTROLS (15.8 (8.5)) (CHI (2) = 45.552; DF = 1; P = 1.49 X 10(-11)). SIGNIFICANT DIFFERENCES (N = 69 SITES) IN METHYLATION PATTERNS WERE OBSERVED BETWEEN CASES AND CONTROLS CONSIDERING A 5% FALSE DISCOVERY RATE. THE MAJORITY OF DIFFERENTIALLY METHYLATED (DM) SITES (91%) WERE ATTRIBUTABLE TO INCREASED VALUES IN THE WOMEN WITH FM. THE DM SITES INCLUDED SIGNIFICANT BIOLOGICAL CLUSTERS INVOLVED IN NEURON DIFFERENTIATION/NERVOUS SYSTEM DEVELOPMENT, SKELETAL/ORGAN SYSTEM DEVELOPMENT, AND CHROMATIN COMPACTION. GENES ASSOCIATED WITH DM SITES WHOSE FUNCTION HAS PARTICULAR RELEVANCE TO FM INCLUDED BDNF, NAT15, HDAC4, PRKCA, RTN1, AND PRKG1. RESULTS SUPPORT THE NEED FOR FUTURE RESEARCH TO FURTHER EXAMINE THE POTENTIAL ROLE OF EPIGENETIC AND ACQUIRED CHROMOSOMAL ALTERATIONS AS A POSSIBLE BIOLOGICAL MECHANISM UNDERLYING FM. 2013 2 2564 36 EPIGENETICS INSIGHTS INTO CHRONIC PAIN: DNA HYPOMETHYLATION IN FIBROMYALGIA-A CONTROLLED PILOT-STUDY. TO EVALUATE CHANGES IN DNA METHYLATION PROFILES IN PATIENTS WITH FIBROMYALGIA (FM) COMPARED TO MATCHED HEALTHY CONTROLS (HCS). ALL INDIVIDUALS UNDERWENT FULL CLINICAL AND NEUROPHYSIOLOGICAL ASSESSMENT BY CORTICAL EXCITABILITY (CE) PARAMETERS MEASURED BY TRANSCRANIAL MAGNETIC STIMULATION. DNA FROM THE PERIPHERAL BLOOD OF PATIENTS WITH FM (N = 24) AND HC (N = 24) WERE ASSESSED USING THE ILLUMINA-HUMANMETHYLATION450 BEADCHIPS. WE IDENTIFIED 1610 DIFFERENTIALLY METHYLATED POSITIONS (DMPS) IN PATIENTS WITH FM DISPLAYING A NONRANDOM DISTRIBUTION IN REGIONS OF THE GENOME. SIXTY-NINE PERCENT OF DMP IN FM WERE HYPOMETHYLATED COMPARED TO HC. DIFFERENTIALLY METHYLATED POSITIONS WERE ENRICHED IN 5 GENOMIC REGIONS (1P34; 6P21; 10Q26; 17Q25; 19Q13). THE FUNCTIONAL CHARACTERIZATION OF 960 GENES RELATED TO DMPS REVEALED AN ENRICHMENT FOR MAPK SIGNALING PATHWAY (N = 18 GENES), REGULATION OF ACTIN CYTOSKELETON (N = 15 GENES), AND FOCAL ADHESION (N = 13 GENES). A GENE-GENE INTERACTION NETWORK ENRICHMENT ANALYSIS REVEALED THE PARTICIPATION OF DNA REPAIR PATHWAYS, MITOCHONDRIA-RELATED PROCESSES, AND SYNAPTIC SIGNALING. EVEN THOUGH DNA WAS EXTRACTED FROM PERIPHERAL BLOOD, THIS SET OF GENES WAS ENRICHED FOR DISORDERS SUCH AS SCHIZOPHRENIA, MOOD DISORDERS, BULIMIA, HYPERPHAGIA, AND OBESITY. REMARKABLY, THE HIERARCHICAL CLUSTERIZATION BASED ON THE METHYLATION LEVELS OF THE 1610 DMPS SHOWED AN ASSOCIATION WITH NEUROPHYSIOLOGICAL MEASUREMENTS OF CE IN FM AND HC. FIBROMYALGIA HAS A HYPOMETHYLATION DNA PATTERN, WHICH IS ENRICHED IN GENES IMPLICATED IN STRESS RESPONSE AND DNA REPAIR/FREE RADICAL CLEARANCE. THESE CHANGES OCCURRED PARALLEL TO CHANGES IN CE PARAMETERS. NEW EPIGENETIC INSIGHTS INTO THE PATHOPHYSIOLOGY OF FM MAY PROVIDE THE BASIS FOR THE DEVELOPMENT OF BIOMARKERS OF THIS DISORDER. 2017 3 1537 30 DNA METHYLATION IN ADOLESCENTS WITH ANXIETY DISORDER: A LONGITUDINAL STUDY. ANXIETY DISORDERS (AD) TYPICALLY MANIFEST IN CHILDREN AND ADOLESCENTS AND MIGHT PERSIST INTO ADULTHOOD. HOWEVER, THERE ARE STILL FEW DATA CONCERNING EPIGENETIC MECHANISMS ASSOCIATED WITH ONSET, PERSISTENCE OR REMISSION OF AD OVER TIME. WE INVESTIGATED A COHORT OF ADOLESCENTS AND YOUNG ADULTS AT BASELINE (AGE; 13.19 +/- 2.38) AND AFTER 5 YEARS AND CLASSIFIED THEM ACCORDING TO THE AD DIAGNOSIS AND THEIR LONGITUDINAL TRAJECTORIES INTO 4 GROUPS: (1) TYPICALLY DEVELOPING COMPARISONS (TDC; CONTROL GROUP, N = 14); (2) INCIDENT (AD IN THE SECOND EVALUATION ONLY, N = 11); (3) PERSISTENT (AD IN BOTH EVALUATIONS, N = 14) AND (4) REMITTENT (AD IN THE FIRST EVALUATION ONLY, N = 8). DNA METHYLATION WAS EVALUATED WITH THE INFINIUM HUMANMETHYLATION450 BEADCHIP FROM SALIVA SAMPLES COLLECTED AT BOTH EVALUATIONS. GENE SET ENRICHMENT ANALYSIS WAS APPLIED TO CONSIDER BIOLOGICAL PATHWAYS. WE FOUND DECREASED DNA METHYLATION IN TDC GROUP WHILE THE CHRONIC CASES OF AD PRESENTED HYPERMETHYLATION IN CENTRAL NERVOUS SYSTEM DEVELOPMENT PATHWAYS. MOREOVER, WE SHOWED THAT THIS PERSISTENT GROUP ALSO PRESENTED HYPERMETHYLATION WHILE THE OTHER THREE GROUPS WERE ASSOCIATED WITH HYPOMETHYLATION IN NERVOUS SYSTEM DEVELOPMENT PATHWAY. INCIDENCE AND REMISSION GROUPS WERE ASSOCIATED WITH INCREASED AND DECREASED METHYLATION IN NEURON DEVELOPMENT PATHWAYS, RESPECTIVELY. LARGER STUDIES ARE LIKELY TO DETECT SPECIFIC GENES RELEVANT TO AD. 2018 4 1909 35 ENRICHMENT OF GENOMIC PATHWAYS BASED ON DIFFERENTIAL DNA METHYLATION PROFILES ASSOCIATED WITH CHRONIC MUSCULOSKELETAL PAIN IN OLDER ADULTS: AN EXPLORATORY STUDY. OUR STUDY AIMED TO IDENTIFY DIFFERENTIALLY METHYLATED CPGS/REGIONS AND THEIR ENRICHED GENOMIC PATHWAYS ASSOCIATED WITH UNDERLYING CHRONIC MUSCULOSKELETAL PAIN IN OLDER INDIVIDUALS. WE RECRUITED COGNITIVELY HEALTHY OLDER ADULTS WITH (N = 20) AND WITHOUT (N = 9) SELF-REPORTED MUSCULOSKELETAL PAIN AND COLLECTED DNA FROM PERIPHERAL BLOOD THAT WAS ANALYZED USING METHYLATIONEPIC ARRAYS. WE IDENTIFIED 31,739 HYPERMETHYLATED CPG AND 10,811 HYPOMETHYLATED CPG PROBES (PS 0.05). NON-HISPANIC BLACK INDIVIDUALS WERE OVERREPRESENTED IN THE PAIN GROUP (P = 0.003). AT RAW P < 0.05 CUTOFF, WE IDENTIFIED A TOTAL OF 19,710 CPG PROBES, INCLUDING 13,951 HYPERMETHYLATED CPG PROBES, FOR WHICH DNA METHYLATION LEVEL WAS HIGHER IN THE GROUPS WITH HIGHEST PAIN GRADES. WE ALSO IDENTIFIED 5,759 HYPOMETHYLATED CPG PROBES FOR WHICH DNA METHYLATION LEVEL WAS LOWER IN THE PAIN GROUPS WITH HIGHER PAIN GRADES. IPA REVEALED THAT PAIN-RELATED DMRS WERE ENRICHED ACROSS MULTIPLE PATHWAYS AND UPSTREAM REGULATORS. THE TOP 10 CANONICAL PATHWAYS WERE LINKED TO CELLULAR SIGNALING PROCESSES RELATED TO IMMUNE RESPONSES (I.E., ANTIGEN PRESENTATION, PD-1, PD-L1 CANCER IMMUNOTHERAPY, B CELL DEVELOPMENT, IL-4 SIGNALING, TH1 AND TH2 ACTIVATION PATHWAY, AND PHAGOSOME MATURATION). MOREOVER, IN TERMS OF UPSTREAM REGULATORS, NDUFAF3 WAS THE MOST SIGNIFICANT (P = 8.6E-04) UPSTREAM REGULATOR. OUR FINDINGS SUPPORT PREVIOUS PRELIMINARY WORK SUGGESTING THE IMPORTANCE OF EPIGENETIC REGULATION OF THE IMMUNE SYSTEM IN KNEE PAIN AND THE NEED FOR FUTURE WORK TO UNDERSTAND THE EPIGENETIC CONTRIBUTIONS TO CHRONIC PAIN. 2022 8 2079 34 EPIGENETIC DNA METHYLATION CHANGES ASSOCIATED WITH HEADACHE CHRONIFICATION: A RETROSPECTIVE CASE-CONTROL STUDY. BACKGROUND THE BIOLOGICAL MECHANISMS OF HEADACHE CHRONIFICATION ARE POORLY UNDERSTOOD. WE AIMED TO IDENTIFY CHANGES IN DNA METHYLATION ASSOCIATED WITH THE TRANSFORMATION FROM EPISODIC TO CHRONIC HEADACHE. METHODS PARTICIPANTS WERE RECRUITED FROM THE POPULATION-BASED NORWEGIAN HUNT STUDY. THIRTY-SIX FEMALE HEADACHE PATIENTS WHO TRANSFORMED FROM EPISODIC TO CHRONIC HEADACHE BETWEEN BASELINE AND FOLLOW-UP 11 YEARS LATER WERE MATCHED AGAINST 35 CONTROLS WITH EPISODIC HEADACHE. DNA METHYLATION WAS QUANTIFIED AT 485,000 CPG SITES, AND CHANGES IN METHYLATION LEVEL AT THESE SITES WERE COMPARED BETWEEN CASES AND CONTROLS BY LINEAR REGRESSION ANALYSIS. DATA WERE ANALYZED IN TWO STAGES (STAGES 1 AND 2) AND IN A COMBINED META-ANALYSIS. RESULTS NONE OF THE TOP 20 CPG SITES IDENTIFIED IN STAGE 1 REPLICATED IN STAGE 2 AFTER MULTIPLE TESTING CORRECTION. IN THE COMBINED META-ANALYSIS THE STRONGEST ASSOCIATED CPG SITES WERE RELATED TO SH2D5 AND NPTX2, TWO BRAIN-EXPRESSED GENES INVOLVED IN THE REGULATION OF SYNAPTIC PLASTICITY. FUNCTIONAL ENRICHMENT ANALYSIS POINTED TO PROCESSES INCLUDING CALCIUM ION BINDING AND ESTROGEN RECEPTOR PATHWAYS. CONCLUSION IN THIS FIRST GENOME-WIDE STUDY OF DNA METHYLATION IN HEADACHE CHRONIFICATION SEVERAL POTENTIALLY IMPLICATED LOCI AND PROCESSES WERE IDENTIFIED. THE STUDY EXEMPLIFIES THE USE OF PROSPECTIVELY COLLECTED POPULATION COHORTS TO SEARCH FOR EPIGENETIC MECHANISMS OF DISEASE. 2018 9 1849 32 EIGHT WEEKS OF PHYSICAL TRAINING DECREASES 2 YEARS OF DNA METHYLATION AGE OF SEDENTARY WOMEN. PURPOSE: THE ACCELERATION OF EPIGENETIC AGE IS A PREDICTOR OF MORTALITY AND CONTRIBUTES TO THE INCREASE IN CHRONIC DISEASES. ADHERENCE TO A HEALTHY LIFESTYLE IS A STRATEGY TO REDUCE EPIGENETIC AGE. THE PRESENT STUDY AIMED TO DETERMINE WHETHER EIGHT WEEKS OF COMBINED (AEROBIC AND STRENGTH) TRAINING (CT) CAN INFLUENCE THE EPIGENETIC AGE OF WOMEN BETWEEN 50 AND 70 YEARS OLD AND THE DIFFERENCES IN SITES AND METHYLATED REGIONS. METHODS: EIGHTEEN WOMEN (AAR(LOW): LOWER AGE ACCELERATION RESIDUAL, N = 10; AAR(HIGH): HIGHER AGE ACCELERATION RESIDUAL, N = 8) PARTICIPATED IN A COMBINED EXERCISE TRAINING PROGRAM (60 MINUTES, 3X A WEEK) FOR EIGHT WEEKS. DNA WAS EXTRACTED FROM WHOLE BLOOD USING THE SALTING OUT TECHNIQUE. DNA METHYLATION WAS PERFORMED USING THE ARRAY TECHNIQUE (ILLUMINA'S INFINIUM METHYLATION BEADCHIP 850K). WE USED THE DNA METHYLATION AGE CALCULATOR PLATFORM TO CALCULATE THE BIOLOGICAL EPIGENETIC AGE. TWO-WAY ANOVA FOLLOWED BY FISHER LSD POSTHOC WAS APPLIED, ADOPTING P < .05. RESULTS: AFTER EIGHT WEEKS OF CT, THERE WERE NO CHANGES TO THE EPIGENETIC AGE ACCELERATION FOR THE AAR(LOW) GROUP (PRE: -2.3 +/- 3.2 TO POST: -2.3 +/- 3.6). HOWEVER, THE AAR(HIGH) GROUP SIGNIFICANTLY DECREASED THE AGE ACCELERATION (PRE: 3.6 +/- 2.6 TO POST: 2.2 +/- 2.7) (GROUP EFFECT, P = .01; TIME EFFECT, P = .31; GROUP VS. TIME EFFECT, P = .005). CONCLUSION: CT FOR EIGHT WEEKS BENEFITS THE EPIGENETIC CLOCK OF WOMEN WITH THE MOST ACCELERATED AGE. 2023 10 381 32 AN EPIGENOME-WIDE ASSOCIATION STUDY OF EARLY-ONSET MAJOR DEPRESSION IN MONOZYGOTIC TWINS. MAJOR DEPRESSION (MD) IS A DEBILITATING MENTAL HEALTH CONDITION WITH PEAK PREVALENCE OCCURRING EARLY IN LIFE. GENOME-WIDE EXAMINATION OF DNA METHYLATION (DNAM) OFFERS AN ATTRACTIVE COMPLEMENT TO STUDIES OF ALLELIC RISK GIVEN IT CAN REFLECT THE COMBINED INFLUENCE OF GENES AND ENVIRONMENT. THE CURRENT STUDY USED MONOZYGOTIC TWINS TO IDENTIFY DIFFERENTIALLY AND VARIABLY METHYLATED REGIONS OF THE GENOME THAT DISTINGUISH TWINS WITH AND WITHOUT A LIFETIME HISTORY OF EARLY-ONSET MD. THE SAMPLE INCLUDED 150 CAUCASIAN MONOZYGOTIC TWINS BETWEEN THE AGES OF 15 AND 20 (73% FEMALE; MAGE = 17.52 SD = 1.28) WHO WERE ASSESSED DURING A DEVELOPMENTAL STAGE CHARACTERIZED BY RELATIVELY DISTINCT NEUROPHYSIOLOGICAL CHANGES. ALL TWINS WERE GENERALLY HEALTHY AND CURRENTLY FREE OF MEDICATIONS WITH PSYCHOTROPIC EFFECTS. DNAM WAS MEASURED IN PERIPHERAL BLOOD CELLS USING THE INFINIUM HUMAN BEADCHIP 450 K ARRAY. MD ASSOCIATIONS WITH EARLY-ONSET MD WERE DETECTED AT 760 DIFFERENTIALLY AND VARIABLY METHYLATED PROBES/REGIONS THAT MAPPED TO 428 GENES. GENES AND GENOMIC REGIONS INVOLVED NEURAL CIRCUITRY FORMATION, PROJECTION, FUNCTIONING, AND PLASTICITY. GENE ENRICHMENT ANALYSES IMPLICATED GENES RELATED TO NEURON STRUCTURES AND NEURODEVELOPMENTAL PROCESSES INCLUDING CELL-CELL ADHESION GENES (E.G., PCDHA GENES). GENES PREVIOUSLY IMPLICATED IN MOOD AND PSYCHIATRIC DISORDERS AS WELL AS CHRONIC STRESS (E.G., NRG3) ALSO WERE IDENTIFIED. DNAM REGIONS ASSOCIATED WITH EARLY-ONSET MD WERE FOUND TO OVERLAP GENETIC LOCI IDENTIFIED IN THE LATEST PSYCHIATRIC GENOMICS CONSORTIUM META-ANALYSIS OF DEPRESSION. UNDERSTANDING THE TIME COURSE OF EPIGENETIC INFLUENCES DURING EMERGING ADULTHOOD MAY CLARIFY DEVELOPMENTAL PHASES WHERE CHANGES IN THE DNA METHYLOME MAY MODULATE INDIVIDUAL DIFFERENCES IN MD RISK. 2020 11 1580 43 DNA METHYLATION PROFILES ARE ASSOCIATED WITH COMPLEX REGIONAL PAIN SYNDROME AFTER TRAUMATIC INJURY. FACTORS CONTRIBUTING TO DEVELOPMENT OF COMPLEX REGIONAL PAIN SYNDROME (CRPS) ARE NOT FULLY UNDERSTOOD. THIS STUDY EXAMINED POSSIBLE EPIGENETIC MECHANISMS THAT MAY CONTRIBUTE TO CRPS AFTER TRAUMATIC INJURY. DNA METHYLATION PROFILES WERE COMPARED BETWEEN INDIVIDUALS DEVELOPING CRPS (N = 9) AND THOSE DEVELOPING NON-CRPS NEUROPATHIC PAIN (N = 38) AFTER UNDERGOING AMPUTATION FOLLOWING MILITARY TRAUMA. LINEAR MODELS FOR MICROARRAY (LIMMA) ANALYSES REVEALED 48 DIFFERENTIALLY METHYLATED CYTOSINE-PHOSPHATE-GUANINE DINUCLEOTIDE (CPG) SITES BETWEEN GROUPS (UNADJUSTED P'S < 0.005), WITH THE TOP GENE COL11A1 MEETING BONFERRONI-ADJUSTED P < 0.05. THE SECOND LARGEST DIFFERENTIAL METHYLATION WAS OBSERVED FOR THE HLA-DRB6 GENE, AN IMMUNE-RELATED GENE LINKED PREVIOUSLY TO CRPS IN A SMALL GENE EXPRESSION STUDY. FOR ALL BUT 7 OF THE SIGNIFICANT CPG SITES, THE CRPS GROUP WAS HYPOMETHYLATED. NUMEROUS FUNCTIONAL GENE ONTOLOGY-BIOLOGICAL PROCESS CATEGORIES WERE SIGNIFICANTLY ENRICHED (FALSE DISCOVERY RATE-ADJUSTED Q VALUE <0.15), INCLUDING MULTIPLE IMMUNE-RELATED CATEGORIES (EG, ACTIVATION OF IMMUNE RESPONSE, IMMUNE SYSTEM DEVELOPMENT, REGULATION OF IMMUNE SYSTEM PROCESSES, AND ANTIGEN PROCESSING AND PRESENTATION). DIFFERENTIALLY METHYLATED GENES WERE MORE HIGHLY CONNECTED IN HUMAN PROTEIN-PROTEIN NETWORKS THAN EXPECTED BY CHANCE (P < 0.05), SUPPORTING THE BIOLOGICAL RELEVANCE OF THE FINDINGS. RESULTS WERE VALIDATED IN AN INDEPENDENT SAMPLE LINKING A DNA BIOBANK WITH ELECTRONIC HEALTH RECORDS (N = 126 CRPS PHENOTYPE, N = 19,768 NON-CRPS CHRONIC PAIN PHENOTYPE). ANALYSES USING PREDIXCAN METHODOLOGY INDICATED DIFFERENCES IN THE GENETICALLY DETERMINED COMPONENT OF GENE EXPRESSION IN 7 OF 48 GENES IDENTIFIED IN METHYLATION ANALYSES (P'S < 0.02). RESULTS SUGGEST THAT IMMUNE- AND INFLAMMATORY-RELATED FACTORS MIGHT CONFER RISK OF DEVELOPING CRPS AFTER TRAUMATIC INJURY. VALIDATION FINDINGS DEMONSTRATE THE POTENTIAL OF USING ELECTRONIC HEALTH RECORDS LINKED TO DNA FOR GENOMIC STUDIES OF CRPS. 2019 12 2633 41 EPIGENOME-WIDE DNA METHYLATION PATTERNS ASSOCIATED WITH FATIGUE IN PRIMARY SJOGREN'S SYNDROME. OBJECTIVE: CHRONIC FATIGUE IS A COMMON, DISABLING AND POORLY UNDERSTOOD PHENOMENON. RECENT STUDIES INDICATE THAT EPIGENETIC MECHANISMS MAY BE INVOLVED IN THE EXPRESSION OF FATIGUE, A PROMINENT FEATURE OF PRIMARY SS (PSS). THE AIM OF THIS STUDY WAS TO INVESTIGATE WHETHER DNA METHYLATION PROFILES OF WHOLE BLOOD ARE ASSOCIATED WITH FATIGUE IN PATIENTS WITH PSS. METHODS: FORTY-EIGHT PSS PATIENTS WITH HIGH (N = 24) OR LOW (N = 24) FATIGUE AS MEASURED BY A VISUAL ANALOGUE SCALE WERE INCLUDED. GENOME-WIDE DNA METHYLATION WAS INVESTIGATED USING THE ILLUMINA HUMANMETHYLATION450 BEADCHIP ARRAY. AFTER QUALITY CONTROL, A TOTAL OF 383 358 CYTOSINE-PHOSPHATE-GUANINE (CPG) SITES REMAINED FOR FURTHER ANALYSIS. AGE, SEX AND DIFFERENTIAL CELL COUNT ESTIMATES WERE INCLUDED AS COVARIATES IN THE ASSOCIATION MODEL. A FALSE DISCOVERY RATE-CORRECTED P < 0.05 WAS CONSIDERED SIGNIFICANT, AND A CUT-OFF OF 3% AVERAGE DIFFERENCE IN METHYLATION LEVELS BETWEEN HIGH- AND LOW-FATIGUE PATIENTS WAS APPLIED. RESULTS: A TOTAL OF 251 DIFFERENTIALLY METHYLATED CPG SITES WERE ASSOCIATED WITH FATIGUE. THE CPG SITE WITH THE MOST PRONOUNCED HYPOMETHYLATION IN PSS HIGH FATIGUE ANNOTATED TO THE SBF2-ANTISENSE RNA1 GENE. THE MOST DISTINCT HYPERMETHYLATION WAS OBSERVED AT A CPG SITE ANNOTATED TO THE LYMPHOTOXIN ALPHA GENE. FUNCTIONAL PATHWAY ANALYSIS OF GENES WITH DIFFERENTLY METHYLATED CPG SITES IN SUBJECTS WITH HIGH VS LOW FATIGUE REVEALED ENRICHMENT IN SEVERAL PATHWAYS ASSOCIATED WITH INNATE AND ADAPTIVE IMMUNITY. CONCLUSION: SOME GENES INVOLVED IN REGULATION OF THE IMMUNE SYSTEM AND IN INFLAMMATION ARE DIFFERENTLY METHYLATED IN PSS PATIENTS WITH HIGH VS LOW FATIGUE. THESE FINDINGS POINT TO FUNCTIONAL NETWORKS THAT MAY UNDERLIE FATIGUE. EPIGENETIC CHANGES COULD CONSTITUTE A FATIGUE-REGULATING MECHANISM IN PSS. 2016 13 2488 39 EPIGENETICALLY DYSREGULATED GENES AND PATHWAYS IMPLICATED IN THE PATHOGENESIS OF NON-SYNDROMIC HIGH MYOPIA. MYOPIA, COMMONLY REFERRED TO AS NEARSIGHTEDNESS, IS ONE OF THE MOST COMMON CAUSES OF VISUAL DISABILITY THROUGHOUT THE WORLD. IT AFFECTS MORE PEOPLE WORLDWIDE THAN ANY OTHER CHRONIC VISUAL IMPAIRMENT CONDITION. ALTHOUGH THE PREVALENCE VARIES AMONG VARIOUS ETHNIC GROUPS, THE INCIDENCE OF MYOPIA IS INCREASING IN ALL POPULATIONS ACROSS GLOBE. THUS, IT IS CONSIDERED A PRESSING PUBLIC HEALTH PROBLEM. BOTH GENETICS AND ENVIRONMENT PLAY A ROLE IN DEVELOPMENT OF MYOPIA. TO ELUCIDATE THE EPIGENETIC MECHANISM(S) UNDERLYING THE PATHOPHYSIOLOGY OF HIGH-MYOPIA, WE CONDUCTED METHYLATION PROFILING IN 18 CASES AND 18 MATCHED CONTROLS (AGED 4-12 YEARS), USING ILLUMINA METHYLATIONEPIC BEADCHIPS ARRAY. THE DEGREE OF MYOPIA WAS VARIABLE AMONG SUBJECTS, RANGING FROM -6 TO -15D. WE IDENTIFIED 1541 HYPERMETHYLATED CPGS, REPRESENTING 1745 GENES (2.0-FOLD OR HIGHER) (FALSE DISCOVERY RATE (FDR) P /= 0.75 IN HIGH-MYOPIA SUBJECTS COMPARED TO CONTROLS. AMONG THESE, 48 CPGS HAD EXCELLENT CORRELATION (AUC >/= 0.90). HEREIN, WE PRESENT THE FIRST GENOME-WIDE DNA METHYLATION ANALYSIS IN A UNIQUE HIGH-MYOPIA COHORT, SHOWING EXTENSIVE AND DISCRETE METHYLATION CHANGES RELATIVE TO CONTROLS. THE GENES WE IDENTIFIED HOLD SIGNIFICANT POTENTIAL AS TARGETS FOR NOVEL THERAPEUTIC INTERVENTION EITHER ALONE, OR IN COMBINATION. 2019 14 2620 30 EPIGENOME-WIDE ASSOCIATION DATA IMPLICATES DNA METHYLATION-MEDIATED GENETIC RISK IN PSORIASIS. BACKGROUND: PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE CHARACTERIZED BY EPIDERMAL HYPERPROLIFERATION AND ALTERED KERATINOCYTE DIFFERENTIATION AND INFLAMMATION AND IS CAUSED BY THE INTERPLAY OF GENETIC AND ENVIRONMENTAL FACTORS. PREVIOUS STUDIES HAVE REVEALED THAT DNA METHYLATION (DNAM) AND GENETIC MAKERS ARE CLOSELY ASSOCIATED WITH PSORIASIS, AND STRONG EVIDENCES HAVE SHOWN THAT DNAM CAN BE CONTROLLED BY GENETIC FACTORS, WHICH ATTRACTED US TO EVALUATE THE RELATIONSHIP AMONG DNAM, GENETIC MAKERS, AND DISEASE STATUS. METHODS: WE UTILIZED THE GENOME-WIDE METHYLATION DATA OF PSORIATIC SKIN (PP, N = 114) AND UNAFFECTED CONTROL SKIN (NN, N = 62) TISSUE SAMPLES IN OUR PREVIOUS STUDY, AND WE PERFORMED WHOLE-GENOME GENOTYPING WITH PERIPHERAL BLOOD OF THE SAME SAMPLES TO EVALUATE THE UNDERLYING GENETIC EFFECT ON SKIN DNA METHYLATION. CAUSAL INFERENCE TEST (CIT) WAS USED TO ASSESS WHETHER DNAM REGULATE GENETIC VARIATION AND GAIN A BETTER UNDERSTANDING OF THE EPIGENETIC BASIS OF PSORIASIS SUSCEPTIBILITY. RESULTS: WE IDENTIFIED 129 SNP-CPG PAIRS ACHIEVING THE SIGNIFICANT ASSOCIATION THRESHOLD, WHICH CONSTITUTED 28 UNIQUE METHYLATION QUANTITATIVE TRAIT LOCI (METHQTL) AND 34 UNIQUE CPGS. THERE ARE 18 SNPS WERE ASSOCIATED WITH PSORIASIS AT A BONFERONI-CORRECTED P < 0.05, AND THESE 18 SNPS FORMED 93 SNP-CPG PAIRS WITH 17 UNIQUE CPG SITES. WE FOUND THAT 11 OF 93 SNP-CPG PAIRS, COMPOSED OF 5 UNIQUE SNPS AND 3 CPG SITES, PRESENTED A METHYLATION-MEDIATED RELATIONSHIP BETWEEN SNPS AND PSORIASIS. THE 3 CPG SITES WERE LOCATED ON THE BODY OF C1ORF106, THE TSS1500 PROMOTER REGION OF DMBX1 AND THE BODY OF SIK3. CONCLUSIONS: THIS STUDY REVEALED THAT DNAM OF SOME GENES CAN BE CONTROLLED BY GENETIC FACTORS AND ALSO MEDIATE RISK VARIATION FOR PSORIASIS IN CHINESE HAN POPULATION AND PROVIDED NOVEL MOLECULAR INSIGHTS INTO THE PATHOGENESIS OF PSORIASIS. 2016 15 382 38 AN EPIGENOME-WIDE STUDY OF BODY MASS INDEX AND DNA METHYLATION IN BLOOD USING PARTICIPANTS FROM THE SISTER STUDY COHORT. BACKGROUND/OBJECTIVES: THE RELATIONSHIP BETWEEN OBESITY AND CHRONIC DISEASE RISK IS WELL-ESTABLISHED; THE UNDERLYING BIOLOGICAL MECHANISMS DRIVING THIS RISK INCREASE MAY INCLUDE OBESITY-RELATED EPIGENETIC MODIFICATIONS. TO EXPLORE THIS HYPOTHESIS, WE CONDUCTED A GENOME-WIDE ANALYSIS OF DNA METHYLATION AND BODY MASS INDEX (BMI) USING DATA FROM A SUBSET OF WOMEN IN THE SISTER STUDY. SUBJECTS/METHODS: THE SISTER STUDY IS A COHORT OF 50 884 US WOMEN WHO HAD A SISTER WITH BREAST CANCER BUT WERE FREE OF BREAST CANCER THEMSELVES AT ENROLLMENT. STUDY PARTICIPANTS COMPLETED EXAMINATIONS WHICH INCLUDED MEASUREMENTS OF HEIGHT AND WEIGHT, AND PROVIDED BLOOD SAMPLES. BLOOD DNA METHYLATION DATA GENERATED WITH THE ILLUMINA INFINIUM HUMANMETHYLATION27 BEADCHIP ARRAY COVERING 27,589 CPG SITES WAS AVAILABLE FOR 871 WOMEN FROM A PRIOR STUDY OF BREAST CANCER AND DNA METHYLATION. TO IDENTIFY DIFFERENTIALLY METHYLATED CPG SITES ASSOCIATED WITH BMI, WE ANALYZED THIS METHYLATION DATA USING ROBUST LINEAR REGRESSION WITH ADJUSTMENT FOR AGE AND CASE STATUS. FOR THOSE CPGS PASSING THE FALSE DISCOVERY RATE SIGNIFICANCE LEVEL, WE EXAMINED THE ASSOCIATION IN A REPLICATION SET COMPRISED OF A NON-OVERLAPPING GROUP OF 187 WOMEN FROM THE SISTER STUDY WHO HAD DNA METHYLATION DATA GENERATED USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP ARRAY. ANALYSIS OF THIS EXPANDED 450 K ARRAY IDENTIFIED ADDITIONAL BMI-ASSOCIATED SITES WHICH WERE INVESTIGATED WITH TARGETED PYROSEQUENCING. RESULTS: FOUR CPG SITES REACHED GENOME-WIDE SIGNIFICANCE (FALSE DISCOVERY RATE (FDR) Q<0.05) IN THE DISCOVERY SET AND ASSOCIATIONS FOR ALL FOUR WERE SIGNIFICANT AT STRICT BONFERRONI CORRECTION IN THE REPLICATION SET. AN ADDITIONAL 23 SITES PASSED FDR IN THE REPLICATION SET AND FIVE WERE REPLICATED BY PYROSEQUENCING IN THE DISCOVERY SET. SEVERAL OF THE GENES IDENTIFIED INCLUDING ANGPT4, RORC, SOCS3, FSD2, XYLT1, ABCG1, STK39, ASB2 AND CRHR2 HAVE BEEN LINKED TO OBESITY AND OBESITY-RELATED CHRONIC DISEASES. CONCLUSIONS: OUR FINDINGS SUPPORT THE HYPOTHESIS THAT OBESITY-RELATED EPIGENETIC DIFFERENCES ARE DETECTABLE IN BLOOD AND MAY BE RELATED TO RISK OF CHRONIC DISEASE. 2017 16 2627 34 EPIGENOME-WIDE ASSOCIATION STUDY OF ADIPOSITY AND FUTURE RISK OF OBESITY-RELATED DISEASES. BACKGROUND: OBESITY IS AN ESTABLISHED RISK FACTOR FOR SEVERAL COMMON CHRONIC DISEASES SUCH AS BREAST AND COLORECTAL CANCER, METABOLIC AND CARDIOVASCULAR DISEASES; HOWEVER, THE BIOLOGICAL BASIS FOR THESE RELATIONSHIPS IS NOT FULLY UNDERSTOOD. TO EXPLORE THE ASSOCIATION OF OBESITY WITH THESE CONDITIONS, WE INVESTIGATED PERIPHERAL BLOOD LEUCOCYTE (PBL) DNA METHYLATION MARKERS FOR ADIPOSITY AND THEIR CONTRIBUTION TO RISK OF INCIDENT BREAST AND COLORECTAL CANCER AND MYOCARDIAL INFARCTION. METHODS: DNA METHYLATION PROFILES (ILLUMINA INFINIUM((R)) HUMANMETHYLATION450 BEADCHIP) FROM 1941 INDIVIDUALS FROM FOUR POPULATION-BASED EUROPEAN COHORTS WERE ANALYSED IN RELATION TO BODY MASS INDEX, WAIST CIRCUMFERENCE, WAIST-HIP AND WAIST-HEIGHT RATIO WITHIN A META-ANALYTICAL FRAMEWORK. IN A SUBSET OF THESE INDIVIDUALS, DATA ON GENOME-WIDE GENE EXPRESSION LEVEL, BIOMARKERS OF GLUCOSE AND LIPID METABOLISM WERE ALSO AVAILABLE. VALIDATION OF METHYLATION MARKERS ASSOCIATED WITH ALL ADIPOSITY MEASURES WAS PERFORMED IN 358 INDIVIDUALS. FINALLY, WE INVESTIGATED THE ASSOCIATION OF OBESITY-RELATED METHYLATION MARKS WITH BREAST, COLORECTAL CANCER AND MYOCARDIAL INFARCTION WITHIN RELEVANT SUBSETS OF THE DISCOVERY POPULATION. RESULTS: WE IDENTIFIED 40 CPG LOCI WITH METHYLATION LEVELS ASSOCIATED WITH AT LEAST ONE ADIPOSITY MEASURE. OF THESE, ONE CPG LOCUS (CG06500161) IN ABCG1 WAS ASSOCIATED WITH ALL FOUR ADIPOSITY MEASURES (P = 9.07X10(-)(8) TO 3.27X10(-18)) AND LOWER TRANSCRIPTIONAL ACTIVITY OF THE FULL-LENGTH ISOFORM OF ABCG1 (P = 6.00X10(-7)), HIGHER TRIGLYCERIDE LEVELS (P = 5.37X10(-)(9)) AND HIGHER TRIGLYCERIDES-TO-HDL CHOLESTEROL RATIO (P = 1.03X10(-10)). OF THE 40 INFORMATIVE AND OBESITY-RELATED CPG LOCI, TWO (IN IL2RB AND FGF18) WERE SIGNIFICANTLY ASSOCIATED WITH COLORECTAL CANCER (INVERSELY, P < 1.6X10(-3)) AND ONE INTERGENIC LOCUS ON CHROMOSOME 1 WAS INVERSELY ASSOCIATED WITH MYOCARDIAL INFARCTION (P < 1.25X10(-3)), INDEPENDENTLY OF OBESITY AND ESTABLISHED RISK FACTORS. CONCLUSION: OUR RESULTS SUGGEST THAT EPIGENETIC CHANGES, IN PARTICULAR ALTERED DNA METHYLATION PATTERNS, MAY BE AN INTERMEDIATE BIOMARKER AT THE INTERSECTION OF OBESITY AND OBESITY-RELATED DISEASES, AND COULD OFFER CLUES AS TO UNDERLYING BIOLOGICAL MECHANISMS. 2018 17 6547 29 TRANSCRIPTOMICS OF LONG-TERM MEDITATION PRACTICE: EVIDENCE FOR PREVENTION OR REVERSAL OF STRESS EFFECTS HARMFUL TO HEALTH. BACKGROUND AND OBJECTIVES: STRESS CAN OVERLOAD ADAPTIVE MECHANISMS, LEADING TO EPIGENETIC EFFECTS HARMFUL TO HEALTH. RESEARCH ON THE REVERSAL OF THESE EFFECTS IS IN ITS INFANCY. EARLY RESULTS SUGGEST SOME MEDITATION TECHNIQUES HAVE HEALTH BENEFITS THAT GROW WITH REPEATED PRACTICE. THIS STUDY FOCUSED ON POSSIBLE TRANSCRIPTOMIC EFFECTS OF 38 YEARS OF TWICE-DAILY TRANSCENDENTAL MEDITATION((R)) (TM((R))) PRACTICE. MATERIALS AND METHODS: FIRST, USING ILLUMINA((R)) BEADCHIP MICROARRAY TECHNOLOGY, DIFFERENCES IN GLOBAL GENE EXPRESSION IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) WERE SOUGHT BETWEEN HEALTHY PRACTITIONERS AND TIGHTLY MATCHED CONTROLS (N = 12, AGE 65). SECOND, THESE MICROARRAY RESULTS WERE VERIFIED ON A SUBSET OF GENES USING QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR) AND WERE VALIDATED USING QPCR IN LARGER TM AND CONTROL GROUPS (N = 45, AGE 63). BIOINFORMATICS INVESTIGATION EMPLOYED INGENUITY((R)) PATHWAY ANALYSIS (IPA((R))), DAVID, GENOMATIX, AND R PACKAGES. RESULTS: THE 200 GENES AND LOCI FOUND TO MEET STRICT CRITERIA FOR DIFFERENTIAL EXPRESSION IN THE MICROARRAY EXPERIMENT SHOWED CONTRASTING PATTERNS OF EXPRESSION THAT DISTINGUISHED THE TWO GROUPS. DIFFERENTIAL EXPRESSION RELATING TO IMMUNE FUNCTION AND ENERGY EFFICIENCY WERE MOST APPARENT. IN THE TM GROUP, RELATIVE TO THE CONTROL, ALL 49 GENES ASSOCIATED WITH INFLAMMATION WERE DOWNREGULATED, WHILE GENES ASSOCIATED WITH ANTIVIRAL AND ANTIBODY COMPONENTS OF THE DEFENSE RESPONSE WERE UPREGULATED. THE LARGEST EXPRESSION DIFFERENCES WERE SHOWN BY SIX GENES RELATED TO ERYTHROCYTE FUNCTION THAT APPEARED TO REFLECT A CONDITION OF LOWER ENERGY EFFICIENCY IN THE CONTROL GROUP. RESULTS SUPPORTING THESE GENE EXPRESSION DIFFERENCES WERE OBTAINED WITH QPCR-MEASURED EXPRESSION BOTH IN THE WELL-MATCHED MICROARRAY GROUPS AND IN THE LARGER, LESS WELL-MATCHED GROUPS. CONCLUSIONS: THESE FINDINGS ARE CONSISTENT WITH PREDICTIONS BASED ON RESULTS FROM EARLIER RANDOMIZED TRIALS OF MEDITATION AND MAY PROVIDE EVIDENCE FOR STRESS-RELATED MOLECULAR MECHANISMS UNDERLYING REDUCTIONS IN ANXIETY, POST-TRAUMATIC STRESS DISORDER (PTSD), CARDIOVASCULAR DISEASE (CVD), AND OTHER CHRONIC DISORDERS AND DISEASES. 2021 18 2653 34 EPIGENOTYPING IN PERIPHERAL BLOOD CELL DNA AND BREAST CANCER RISK: A PROOF OF PRINCIPLE STUDY. BACKGROUND: EPIGENETIC CHANGES ARE EMERGING AS ONE OF THE MOST IMPORTANT EVENTS IN CARCINOGENESIS. TWO ALTERATIONS IN THE PATTERN OF DNA METHYLATION IN BREAST CANCER (BC) HAVE BEEN PREVIOUSLY REPORTED; ACTIVE ESTROGEN RECEPTOR-ALPHA (ER-ALPHA) IS ASSOCIATED WITH DECREASED METHYLATION OF ER-ALPHA TARGET (ERT) GENES, AND POLYCOMB GROUP TARGET (PCGT) GENES ARE MORE LIKELY THAN OTHER GENES TO HAVE PROMOTER DNA HYPERMETHYLATION IN CANCER. HOWEVER, WHETHER DNA METHYLATION IN NORMAL UNRELATED CELLS IS ASSOCIATED WITH BC RISK AND WHETHER THESE IMPRINTS CAN BE RELATED TO FACTORS WHICH CAN BE MODIFIED BY THE ENVIRONMENT, IS UNCLEAR. METHODOLOGY/PRINCIPAL FINDINGS: USING QUANTITATIVE METHYLATION ANALYSIS IN A CASE-CONTROL STUDY (N = 1,083) WE FOUND THAT DNA METHYLATION OF PERIPHERAL BLOOD CELL DNA PROVIDES GOOD PREDICTION OF BC RISK. WE ALSO REPORT THAT INVASIVE DUCTAL AND INVASIVE LOBULAR BC IS CHARACTERIZED BY TWO DIFFERENT SETS OF GENES, THE LATTER PARTICULAR BY GENES INVOLVED IN THE DIFFERENTIATION OF THE MESENCHYME (PITX2, TITF1, GDNF AND MYOD1). FINALLY WE DEMONSTRATE THAT ONLY ERT GENES PREDICT ER POSITIVE BC; LACK OF PERIPHERAL BLOOD CELL DNA METHYLATION OF ZNF217 PREDICTED BC INDEPENDENT OF AGE AND FAMILY HISTORY (ODDS RATIO 1.49; 95% CONFIDENCE INTERVAL 1.12-1.97; P = 0.006) AND WAS ASSOCIATED WITH ER-ALPHA BIOACTIVITY IN THE CORRESPONDING SERUM. CONCLUSION/SIGNIFICANCE: THIS FIRST LARGE-SCALE EPIGENOTYPING STUDY DEMONSTRATES THAT DNA METHYLATION MAY SERVE AS A LINK BETWEEN THE ENVIRONMENT AND THE GENOME. FACTORS THAT CAN BE MODULATED BY THE ENVIRONMENT (LIKE ESTROGENS) LEAVE AN IMPRINT IN THE DNA OF CELLS THAT ARE UNRELATED TO THE TARGET ORGAN AND INDICATE THE PREDISPOSITION TO DEVELOP A CANCER. FURTHER RESEARCH WILL NEED TO DEMONSTRATE WHETHER DNA METHYLATION PROFILES WILL BE ABLE TO SERVE AS A NEW TOOL TO PREDICT THE RISK OF DEVELOPING CHRONIC DISEASES WITH SUFFICIENT ACCURACY TO GUIDE PREVENTIVE MEASURES. 2008 19 1345 31 DETECTION OF DIFFERENTIALLY METHYLATED REGIONS USING BAYES FACTOR FOR ORDINAL GROUP RESPONSES. RESEARCHERS IN GENOMICS ARE INCREASINGLY INTERESTED IN EPIGENETIC FACTORS SUCH AS DNA METHYLATION, BECAUSE THEY PLAY AN IMPORTANT ROLE IN REGULATING GENE EXPRESSION WITHOUT CHANGES IN THE DNA SEQUENCE. THERE HAVE BEEN SIGNIFICANT ADVANCES IN DEVELOPING STATISTICAL METHODS TO DETECT DIFFERENTIALLY METHYLATED REGIONS (DMRS) ASSOCIATED WITH BINARY DISEASE STATUS. MOST OF THESE METHODS ARE BEING DEVELOPED FOR DETECTING DIFFERENTIAL METHYLATION RATES BETWEEN CASES AND CONTROLS. WE CONSIDER MULTIPLE SEVERITY LEVELS OF DISEASE, AND DEVELOP A BAYESIAN STATISTICAL METHOD TO DETECT THE REGION WITH INCREASING (OR DECREASING) METHYLATION RATES AS THE DISEASE SEVERITY INCREASES. PATIENTS ARE CLASSIFIED INTO MORE THAN TWO GROUPS, BASED ON THE DISEASE SEVERITY (E.G., STAGES OF CANCER), AND DMRS ARE DETECTED BY USING MOVING WINDOWS ALONG THE GENOME. WITHIN EACH WINDOW, THE BAYES FACTOR IS CALCULATED TO TEST THE HYPOTHESIS OF MONOTONIC INCREASE IN METHYLATION RATES CORRESPONDING TO SEVERITY OF THE DISEASE VERSUS NO DIFFERENCE. A MIXED-EFFECT MODEL IS USED TO INCORPORATE THE CORRELATION OF METHYLATION RATES OF NEARBY CPG SITES IN THE REGION. RESULTS FROM EXTENSIVE SIMULATION INDICATE THAT OUR PROPOSED METHOD IS STATISTICALLY VALID AND REASONABLY POWERFUL. WE DEMONSTRATE OUR APPROACH ON A BISULFITE SEQUENCING DATASET FROM A CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) STUDY. 2019 20 1525 36 DNA METHYLATION CHANGES IN GENES INVOLVED IN INFLAMMATION AND DEPRESSION IN FIBROMYALGIA: A PILOT STUDY. OBJECTIVES: THE PRESENT PILOT STUDY AIMS TO INVESTIGATE DNA METHYLATION CHANGES OF GENES RELATED TO FIBROMYALGIA (FM) DEVELOPMENT AND ITS MAIN COMORBID SYMPTOMS, INCLUDING SLEEP IMPAIRMENT, INFLAMMATION, DEPRESSION AND OTHER PSYCHIATRIC DISORDERS. EPIGENETIC MODIFICATIONS MIGHT TRIGGER OR PERPETUATE COMPLEX INTERPLAY BETWEEN PAIN TRANSDUCTION/TRANSMISSION, CENTRAL PAIN PROCESSING AND EXPERIENCED STRESSORS IN VULNERABLE INDIVIDUALS. METHODS: WE CONDUCTED DNA METHYLATION ANALYSIS BY TARGETED BISULFITE NGS SEQUENCING TESTING DIFFERENTIAL METHYLATION IN 112 GENOMIC REGIONS FROM LEUKOCYTES OF EIGHT WOMEN WITH FM AND THEIR EIGHT HEALTHY SISTERS AS CONTROLS. RESULTS: TESTS FOR DIFFERENTIALLY METHYLATED REGIONS AND CYTOSINES BROUGHT FOCUS ON THE GRM2 GENE, ENCODING THE METABOTROPIC GLUTAMATE RECEPTOR2. THE SLIGHTLY INCREASED DNA METHYLATION OBSERVED IN THE GRM2 REGION OF FM PATIENTS MAY CONFIRM THE INVOLVEMENT OF THE GLUTAMATE PATHWAY IN THIS PATHOLOGICAL CONDITION. LOGISTIC REGRESSION HIGHLIGHTED THE SIMULTANEOUS ASSOCIATION OF METHYLATION LEVELS OF DEPRESSION AND INFLAMMATION-RELATED GENES WITH FM. CONCLUSIONS: ALTOGETHER, THE RESULTS EVIDENCE THE GLUTAMATE PATHWAY INVOLVEMENT IN FM AND SUPPORT THE IDEA THAT A COMBINATION OF METHYLATED AND UNMETHYLATED GENES COULD REPRESENT A RISK FACTOR TO FM OR ITS CONSEQUENCE, MORE THAN SINGLE GENES. FURTHER STUDIES ON THE IDENTIFIED BIOMARKERS COULD CONTRIBUTE TO UNRAVEL THE CAUSATIVE UNDERLYING FM MECHANISMS, GIVING RELIABLE DIRECTIONS TO RESEARCH, IMPROVING THE DIAGNOSIS AND EFFECTIVE THERAPIES. 2021