1 57 142 A GENOME-WIDE ASSOCIATION STUDY OF QUANTITATIVE COMPUTED TOMOGRAPHIC EMPHYSEMA IN KOREAN POPULATIONS. EMPHYSEMA IS AN IMPORTANT FEATURE OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). GENETIC FACTORS LIKELY AFFECT EMPHYSEMA PATHOGENESIS, BUT THIS QUESTION HAS PREDOMINANTLY BEEN STUDIED IN THOSE OF EUROPEAN ANCESTRY. IN THIS STUDY, WE SOUGHT TO DETERMINE GENETIC COMPONENTS OF EMPHYSEMA SEVERITY AND CHARACTERIZE THE POTENTIAL FUNCTION OF THE ASSOCIATED LOCI IN KOREAN POPULATION. WE PERFORMED A GENOME-WIDE ASSOCIATION STUDY (GWAS) ON QUANTITATIVE EMPHYSEMA IN SUBJECTS WITH OR WITHOUT COPD FROM TWO KOREAN COPD COHORTS. WE INVESTIGATED THE FUNCTIONAL CONSEQUENCES OF THE LOCI USING EPIGENETIC ANNOTATION AND GENE EXPRESSION DATA. WE ALSO COMPARED OUR GWAS RESULTS WITH AN EPIGENOME-WIDE ASSOCIATION STUDY AND PREVIOUS DIFFERENTIAL GENE EXPRESSION ANALYSIS. IN TOTAL, 548 SUBJECTS (476 [86.9%] MALE) INCLUDING 514 COPD PATIENTS WERE EVALUATED. WE IDENTIFIED ONE GENOME-WIDE SIGNIFICANT SNP (P < 5.0 X 10(-8)), RS117084279, NEAR PIBF1. WE IDENTIFIED AN ADDITIONAL 57 SNPS (P < 5.0 X 10(-6)) ASSOCIATED WITH EMPHYSEMA IN ALL SUBJECTS, AND 106 SNPS (P < 5.0 X 10(-6)) IN COPD PATIENTS. OF THESE CANDIDATE SNPS, 2 (RS12459249, RS11667314) NEAR CYP2A6 WERE EXPRESSION QUANTITATIVE TRAIT LOCI IN LUNG TISSUE AND A SNP (RS11214944) NEAR NNMT WAS AN EXPRESSION QUANTITATIVE TRAIT LOCUS IN WHOLE BLOOD. OF NOTE, RS11214944 WAS IN LINKAGE DISEQUILIBRIUM WITH VARIANTS IN ENHANCER HISTONE MARKS IN LUNG TISSUE. SEVERAL GENES NEAR ADDITIONAL SNPS WERE IDENTIFIED IN OUR PREVIOUS EWAS STUDY WITH NOMINAL LEVEL OF SIGNIFICANCE. WE IDENTIFIED A NOVEL SNP ASSOCIATED WITH QUANTITATIVE EMPHYSEMA ON CT. INCLUDING THE NOVEL SNP, SEVERAL CANDIDATE SNPS IN OUR STUDY MAY PROVIDE CLUES TO THE GENETIC ETIOLOGY OF EMPHYSEMA IN ASIAN POPULATIONS. FURTHER RESEARCH AND VALIDATION OF THE LOCI WILL HELP DETERMINE THE GENETIC FACTORS FOR THE DEVELOPMENT OF EMPHYSEMA. 2021 2 667 45 BLOOD-BASED EPIGENOME-WIDE ANALYSES OF 19 COMMON DISEASE STATES: A LONGITUDINAL, POPULATION-BASED LINKED COHORT STUDY OF 18,413 SCOTTISH INDIVIDUALS. BACKGROUND: DNA METHYLATION IS A DYNAMIC EPIGENETIC MECHANISM THAT OCCURS AT CYTOSINE-PHOSPHATE-GUANINE DINUCLEOTIDE (CPG) SITES. EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) INVESTIGATE THE STRENGTH OF ASSOCIATION BETWEEN METHYLATION AT INDIVIDUAL CPG SITES AND HEALTH OUTCOMES. ALTHOUGH BLOOD METHYLATION MAY ACT AS A PERIPHERAL MARKER OF COMMON DISEASE STATES, PREVIOUS EWAS HAVE TYPICALLY FOCUSED ONLY ON INDIVIDUAL CONDITIONS AND HAVE HAD LIMITED POWER TO DISCOVER DISEASE-ASSOCIATED LOCI. THIS STUDY EXAMINED THE ASSOCIATION OF BLOOD DNA METHYLATION WITH THE PREVALENCE OF 14 DISEASE STATES AND THE INCIDENCE OF 19 DISEASE STATES IN A SINGLE POPULATION OF OVER 18,000 SCOTTISH INDIVIDUALS. METHODS AND FINDINGS: DNA METHYLATION WAS ASSAYED AT 752,722 CPG SITES IN WHOLE-BLOOD SAMPLES FROM 18,413 VOLUNTEERS IN THE FAMILY-STRUCTURED, POPULATION-BASED COHORT STUDY GENERATION SCOTLAND (AGE RANGE 18 TO 99 YEARS). EWAS TESTED FOR CROSS-SECTIONAL ASSOCIATIONS BETWEEN BASELINE CPG METHYLATION AND 14 PREVALENT DISEASE STATES, AND FOR LONGITUDINAL ASSOCIATIONS BETWEEN BASELINE CPG METHYLATION AND 19 INCIDENT DISEASE STATES. PREVALENT CASES WERE SELF-REPORTED ON HEALTH QUESTIONNAIRES AT THE BASELINE. INCIDENT CASES WERE IDENTIFIED USING LINKAGE TO SCOTTISH PRIMARY (READ 2) AND SECONDARY (ICD-10) CARE RECORDS, AND THE CENSORING DATE WAS SET TO OCTOBER 2020. THE MEAN TIME-TO-DIAGNOSIS RANGED FROM 5.0 YEARS (FOR CHRONIC PAIN) TO 11.7 YEARS (FOR CORONAVIRUS DISEASE 2019 (COVID-19) HOSPITALISATION). THE 19 DISEASE STATES CONSIDERED IN THIS STUDY WERE SELECTED IF THEY WERE PRESENT ON THE WORLD HEALTH ORGANISATION'S 10 LEADING CAUSES OF DEATH AND DISEASE BURDEN OR INCLUDED IN BASELINE SELF-REPORT QUESTIONNAIRES. EWAS MODELS WERE ADJUSTED FOR AGE AT METHYLATION TYPING, SEX, ESTIMATED WHITE BLOOD CELL COMPOSITION, POPULATION STRUCTURE, AND 5 COMMON LIFESTYLE RISK FACTORS. A STRUCTURED LITERATURE REVIEW WAS ALSO CONDUCTED TO IDENTIFY EXISTING EWAS FOR ALL 19 DISEASE STATES TESTED. THE MEDLINE, EMBASE, WEB OF SCIENCE, AND PREPRINT SERVERS WERE SEARCHED TO RETRIEVE RELEVANT ARTICLES INDEXED AS OF MARCH 27, 2023. FIFTY-FOUR OF APPROXIMATELY 2,000 INDEXED ARTICLES MET OUR INCLUSION CRITERIA: ASSAYED BLOOD-BASED DNA METHYLATION, HAD >20 INDIVIDUALS IN EACH COMPARISON GROUP, AND EXAMINED ONE OF THE 19 CONDITIONS CONSIDERED. FIRST, WE ASSESSED WHETHER THE ASSOCIATIONS IDENTIFIED IN OUR STUDY WERE REPORTED IN PREVIOUS STUDIES. WE IDENTIFIED 69 ASSOCIATIONS BETWEEN CPGS AND THE PREVALENCE OF 4 CONDITIONS, OF WHICH 58 WERE NEWLY DESCRIBED. THE CONDITIONS WERE BREAST CANCER, CHRONIC KIDNEY DISEASE, ISCHEMIC HEART DISEASE, AND TYPE 2 DIABETES MELLITUS. WE ALSO UNCOVERED 64 CPGS THAT ASSOCIATED WITH THE INCIDENCE OF 2 DISEASE STATES (COPD AND TYPE 2 DIABETES), OF WHICH 56 WERE NOT REPORTED IN THE SURVEYED LITERATURE. SECOND, WE ASSESSED REPLICATION ACROSS EXISTING STUDIES, WHICH WAS DEFINED AS THE REPORTING OF AT LEAST 1 COMMON SITE IN >2 STUDIES THAT EXAMINED THE SAME CONDITION. ONLY 6/19 DISEASE STATES HAD EVIDENCE OF SUCH REPLICATION. THE LIMITATIONS OF THIS STUDY INCLUDE THE NONCONSIDERATION OF MEDICATION DATA AND A POTENTIAL LACK OF GENERALIZABILITY TO INDIVIDUALS THAT ARE NOT OF SCOTTISH AND EUROPEAN ANCESTRY. CONCLUSIONS: WE DISCOVERED OVER 100 ASSOCIATIONS BETWEEN BLOOD METHYLATION SITES AND COMMON DISEASE STATES, INDEPENDENTLY OF MAJOR CONFOUNDING RISK FACTORS, AND A NEED FOR GREATER STANDARDISATION AMONG EWAS ON HUMAN DISEASE. 2023 3 4750 37 NOVEL REGIONAL AGE-ASSOCIATED DNA METHYLATION CHANGES WITHIN HUMAN COMMON DISEASE-ASSOCIATED LOCI. BACKGROUND: ADVANCING AGE PROGRESSIVELY IMPACTS ON RISK AND SEVERITY OF CHRONIC DISEASE. IT ALSO MODIFIES THE EPIGENOME, WITH CHANGES IN DNA METHYLATION, DUE TO BOTH RANDOM DRIFT AND VARIATION WITHIN SPECIFIC FUNCTIONAL LOCI. RESULTS: IN A DISCOVERY SET OF 2238 PERIPHERAL-BLOOD GENOME-WIDE DNA METHYLOMES AGED 19-82 YEARS, WE IDENTIFY 71 AGE-ASSOCIATED DIFFERENTIALLY METHYLATED REGIONS WITHIN THE LINKAGE DISEQUILIBRIUM BLOCKS OF THE SINGLE NUCLEOTIDE POLYMORPHISMS FROM THE NIH GENOME-WIDE ASSOCIATION STUDY CATALOGUE. THIS INCLUDED 52 NOVEL REGIONS, 29 WITHIN LOCI NOT COVERED BY 450 K OR 27 K ILLUMINA ARRAY, AND WITH ENRICHMENT FOR DNASE-I HYPERSENSITIVITY SITES ACROSS THE FULL RANGE OF TISSUES. THESE AGE-ASSOCIATED DIFFERENTIALLY METHYLATED REGIONS ALSO SHOW MARKED ENRICHMENT FOR ENHANCERS AND POISED PROMOTERS ACROSS MULTIPLE CELL TYPES. IN A REPLICATION SET OF 2084 DNA METHYLOMES, 95.7 % OF THE AGE-ASSOCIATED DIFFERENTIALLY METHYLATED REGIONS SHOWED THE SAME DIRECTION OF AGEING EFFECT, WITH 80.3 % AND 53.5 % REPLICATED TO P < 0.05 AND P < 1.85 X 10(-8), RESPECTIVELY. CONCLUSION: BY ANALYSING THE FUNCTIONALLY ENRICHED DISEASE AND TRAIT-ASSOCIATED REGIONS OF THE HUMAN GENOME, WE IDENTIFY NOVEL EPIGENETIC AGEING CHANGES, WHICH COULD BE USEFUL BIOMARKERS OR PROVIDE MECHANISTIC INSIGHTS INTO AGE-RELATED COMMON DISEASES. 2016 4 5118 33 POSSIBLE ASSOCIATION BETWEEN GERMLINE METHYLENETETRAHYDROFOLATE REDUCTASE GENE POLYMORPHISMS AND PSORIASIS RISK IN A TURKISH POPULATION. BACKGROUND: PSORIASIS IS A COMMON CHRONIC INFLAMMATORY SKIN DISEASE CAUSED BY GENETIC AND EPIGENETIC FACTORS. THERE ARE CONFLICTING RESULTS IN THE LITERATURE ABOUT THE ASSOCIATION BETWEEN PSORIASIS AND THE METHYLENETETRAHYDROFOLATE REDUCTASE GENE (MTHFR), RANGING FROM STRONG LINKAGE TO NO ASSOCIATION. AIM: TO INVESTIGATE THE ASSOCIATION BETWEEN THE GERMLINE MTHFR POLYMORPHISMS C677T AND A1298C WITH PSORIASIS RISK IN A TURKISH POPULATION. METHODS: THE STUDY ENROLLED 84 PATIENTS WITH PSORIASIS AND 212 HEALTHY CONTROLS (HCS) WITHOUT ANY HISTORY OF PSORIASIS. DNA WAS EXTRACTED FROM PERIPHERAL BLOOD SAMPLES OF PATIENTS AND HCS, AND REAL-TIME PCR WAS USED FOR GENOTYPING. RESULTS WERE COMPARED BY PEARSON CHI(2) TEST AND MULTIPLE LOGISTIC REGRESSION MODELS. RESULTS: THE FREQUENCY OF BOTH THE MTHFR 677TT AND A1298C (HOMOZYGOUS) GENOTYPES WAS STATISTICALLY SIGNIFICANTLY DIFFERENT FROM HCS. POINT MUTATIONS WERE DETECTED IN ALL PATIENTS WITH EARLY-ONSET PSORIASIS (BEFORE THE AGE OF 20 YEARS). THE T ALLELE OF MTHFR 677 AND THE C ALLELE OF MTHFR 1298 INCREASED PSORIASIS RISK BY 12.4- AND 17.0-FOLD, RESPECTIVELY, IN PATIENTS COMPARED WITH HCS. CONCLUSION: A POSSIBLE ASSOCIATION WAS DETECTED BETWEENGERMLINE MTHFR 677 C>T AND 1298 A>C GENOTYPES AND PSORIASIS RISK IN A TURKISH POPULATION. THESE RESULTS NEED TO BE CONFIRMED IN FURTHER STUDIES WITH LARGER SAMPLE SIZES. 2017 5 2643 33 EPIGENOMIC ASSOCIATION ANALYSIS IDENTIFIES SMOKING-RELATED DNA METHYLATION SITES IN AFRICAN AMERICANS. CIGARETTE SMOKING IS AN ENVIRONMENTAL RISK FACTOR FOR MANY CHRONIC DISEASES, AND DISEASE RISK CAN OFTEN BE MANAGED BY SMOKING CONTROL. SMOKING CAN INDUCE CELLULAR AND MOLECULAR CHANGES, INCLUDING EPIGENETIC MODIFICATION, BUT THE SHORT- AND LONG-TERM EPIGENETIC MODIFICATIONS CAUSED BY CIGARETTE SMOKING AT THE GENE LEVEL HAVE NOT BEEN WELL UNDERSTOOD. RECENT STUDIES HAVE IDENTIFIED SMOKING-RELATED DNA METHYLATION (DNAM) SITES IN CAUCASIANS. TO DETERMINE WHETHER THE SAME DNAM SITES ASSOCIATE WITH SMOKING IN AFRICAN AMERICANS, AND TO IDENTIFY NOVEL SMOKING-RELATED DNAM SITES, WE CONDUCTED A METHYLOME-WIDE ASSOCIATION STUDY OF CIGARETTE SMOKING USING A DISCOVERY SAMPLE OF 972 AFRICAN AMERICANS, AND A REPLICATION SAMPLE OF 239 AFRICAN AMERICANS WITH TWO ARRAY-BASED METHODS. AMONG 15 DNAM SITES SIGNIFICANTLY ASSOCIATED WITH SMOKING AFTER CORRECTION FOR MULTIPLE TESTING IN OUR DISCOVERY SAMPLE, 5 DNAM SITES ARE REPLICATED IN AN INDEPENDENT COHORT, AND 14 SITES IN THE REPLICATION SAMPLE HAVE EFFECTS IN THE SAME DIRECTION AS IN THE DISCOVERY SAMPLE. THE TOP TWO SMOKING-RELATED DNAM SITES IN F2RL3 (FACTOR II RECEPTOR-LIKE 3) AND GPR15 (G-PROTEIN-COUPLED RECEPTOR 15) OBSERVED IN AFRICAN AMERICANS ARE CONSISTENT WITH PREVIOUS FINDINGS IN CAUCASIANS. THE ASSOCIATIONS BETWEEN THE REPLICATED DNAM SITES AND SMOKING REMAIN SIGNIFICANT AFTER ADJUSTING FOR GENETIC BACKGROUND. DESPITE THE DISTINCT GENETIC BACKGROUND BETWEEN AFRICAN AMERICANS AND CAUCASIANS, THE DNAM FROM THE TWO ETHNIC GROUPS SHARES COMMON ASSOCIATIONS WITH CIGARETTE SMOKING, WHICH SUGGESTS A COMMON MOLECULAR MECHANISM OF EPIGENETIC MODIFICATION INFLUENCED BY ENVIRONMENTAL EXPOSURE. 2013 6 3420 48 HUMAN LUNG DNA METHYLATION QUANTITATIVE TRAIT LOCI COLOCALIZE WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE GENOME-WIDE ASSOCIATION LOCI. RATIONALE: AS THE THIRD LEADING CAUSE OF DEATH IN THE UNITED STATES, THE IMPACT OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) MAKES IDENTIFICATION OF ITS MOLECULAR MECHANISMS OF GREAT IMPORTANCE. GENOME-WIDE ASSOCIATION STUDIES (GWASS) HAVE IDENTIFIED MULTIPLE GENOMIC REGIONS ASSOCIATED WITH COPD. HOWEVER, GENETIC VARIATION ONLY EXPLAINS A SMALL FRACTION OF THE SUSCEPTIBILITY TO COPD, AND SUB-GENOME-WIDE SIGNIFICANT LOCI MAY PLAY A ROLE IN PATHOGENESIS. OBJECTIVES: REGULATORY ANNOTATION WITH EPIGENETIC EVIDENCE MAY GIVE PRIORITY FOR FURTHER INVESTIGATION, PARTICULARLY FOR GWAS ASSOCIATIONS IN NONCODING REGIONS. WE PERFORMED INTEGRATIVE GENOMICS ANALYSES USING DNA METHYLATION PROFILING AND GENOME-WIDE SNP GENOTYPING FROM LUNG TISSUE SAMPLES FROM 90 SUBJECTS WITH COPD AND 36 CONTROL SUBJECTS. METHODS: WE PERFORMED METHYLATION QUANTITATIVE TRAIT LOCI (MQTL) ANALYSES, TESTING FOR SNPS ASSOCIATED WITH PERCENT DNA METHYLATION AND ASSESSED THE COLOCALIZATION OF THESE RESULTS WITH PREVIOUS COPD GWAS FINDINGS USING BAYESIAN METHODS IN THE R PACKAGE COLOC TO HIGHLIGHT POTENTIAL REGULATORY FEATURES OF THE LOCI. MEASUREMENTS AND MAIN RESULTS: WE IDENTIFIED 942,068 UNIQUE SNPS AND 33,996 UNIQUE CPG SITES AMONG THE SIGNIFICANT (5% FALSE DISCOVERY RATE) CIS-MQTL RESULTS. THE GENOME-WIDE SIGNIFICANT AND SUBTHRESHOLD (P < 10(-4)) GWAS SNPS WERE ENRICHED IN THE SIGNIFICANT MQTL SNPS (HYPERGEOMETRIC TEST P < 0.00001). WE OBSERVED ENRICHMENT FOR SITES LOCATED IN CPG SHORES AND SHELVES, BUT NOT CPG ISLANDS. USING BAYESIAN COLOCALIZATION, WE IDENTIFIED LOCI IN REGIONS NEAR KCNK3, EEFSEC, PIK3CD, DCDC2C, TCERG1L, FRMD4B, AND IL27. CONCLUSIONS: COLOCALIZATION OF MQTL AND GWAS LOCI PROVIDES REGULATORY CHARACTERIZATION OF SIGNIFICANT AND SUBTHRESHOLD GWAS FINDINGS, SUPPORTING A ROLE FOR GENETIC CONTROL OF METHYLATION IN COPD PATHOGENESIS. 2018 7 2622 40 EPIGENOME-WIDE ASSOCIATION STUDIES IN ASTHMA: A SYSTEMATIC REVIEW. OBJECTIVE: ASTHMA IS A COMMON CHRONIC RESPIRATORY AIRWAY DISEASE INFLUENCED BY ENVIRONMENTAL FACTORS AND POSSIBLY THEIR INTERACTION WITH THE HUMAN GENOME CAUSING EPIGENETIC CHANGES. EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) HAVE MAINLY INVESTIGATED DNA METHYLATION AND ITS ASSOCIATION WITH DISEASE OR TRAITS, EXPOSURE FACTORS OR GENE EXPRESSION. THIS SYSTEMATIC REVIEW AIMED TO IDENTIFY ALL EWAS ASSESSING DIFFERENTIALLY METHYLATED SITES ASSOCIATED WITH ASTHMA IN HUMANS. DESIGN: STRUCTURED SYSTEMATIC LITERATURE SEARCH FOLLOWING PRISMA GUIDELINES, NEWCASTLE-OTTAWA SCALE (NOS) FOR COHORT STUDIES WAS USED FOR BIAS ASSESSMENT. DATA SOURCES: WE SEARCHED PUBMED AND EMBASE DATABASES FROM 2005 TO 2019. ELIGIBILITY CRITERIA: EPIGENOME-WIDE ASSOCIATION STUDIES TESTING ASSOCIATION BETWEEN DIFFERENTIAL METHYLATION AND ASTHMA IN HUMANS. RESULTS: OVERALL, WE IDENTIFIED 16 EWAS STUDIES COMPLYING WITH OUR SEARCH CRITERIA. TWELVE STUDIES WERE CONDUCTED ON CHILDREN, AND 10 WERE CONDUCTED ON SAMPLE SIZES <150 SUBJECTS. FOUR HUNDRED AND NINETEEN CPGS WERE REPORTED IN CHILDREN STUDIES AFTER CORRECTION FOR MULTIPLE TESTING. IN THE ADULT STUDIES, THOUSANDS OF DIFFERENTIALLY METHYLATED SITES WERE IDENTIFIED. DIFFERENTIAL METHYLATION IN INFLAMMATORY-RELATED GENES CORRELATED WITH HIGHER LEVELS OF GENE EXPRESSIONS OF INFLAMMATORY MODULATORS IN ASTHMA. DIFFERENTIALLY METHYLATED GENES ASSOCIATED WITH ASTHMA INCLUDED SMAD3, SERPINC1, PROK1, IL13, RUNX3 AND TIGIT. FORTY-ONE CPGS WERE REPLICATED AT LEAST ONCE IN BLOOD SAMPLES, AND 28 CPGS WERE REPLICATED IN NASAL SAMPLES. CONCLUSION: ALTHOUGH MANY DIFFERENTIALLY METHYLATED CPGS IN GENES KNOWN TO BE INVOLVED IN ASTHMA HAVE BEEN IDENTIFIED IN EWAS TO DATE, WE CONCLUDE THAT FURTHER STUDIES OF LARGER SAMPLE SIZES AND ANALYSES OF DIFFERENTIAL METHYLATION BETWEEN DIFFERENT PHENOTYPES ARE NEEDED IN ORDER TO COMPREHENSIVELY EVALUATE THE ROLE OF EPIGENETIC FACTORS IN THE PATHOPHYSIOLOGY AND HETEROGENEITY OF ASTHMA, AND THE POTENTIAL CLINICAL UTILITY TO PREDICT OR CLASSIFY PATIENTS WITH ASTHMA. 2019 8 6761 34 X CHROMOSOME-WIDE ANALYSIS IDENTIFIES DNA METHYLATION SITES INFLUENCED BY CIGARETTE SMOKING. BACKGROUND: TOBACCO SMOKING IS A MAJOR CAUSE OF CHRONIC DISEASE WORLDWIDE. SMOKING MAY INDUCE CELLULAR AND MOLECULAR CHANGES INCLUDING EPIGENETIC MODIFICATION, WITH BOTH SHORT-TERM AND LONG-TERM MODIFICATION PATTERNS THAT MAY CONTRIBUTE TO PHENOTYPIC EXPRESSION OF DISEASES. RECENT EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) HAVE IDENTIFIED DOZENS OF SMOKING-RELATED DNA METHYLATION (DNAM) SITES. HOWEVER, THE X CHROMOSOMAL DNAM SITES HAVE BEEN LARGELY OVERLOOKED DUE TO A LACK OF AN ANALYTICAL FRAMEWORK FOR DEALING WITH THE SEX-DIMORPHIC DISTRIBUTION. TO IDENTIFY NOVEL SMOKING-RELATED DNAM SITES ON THE X CHROMOSOME, WE EXAMINED THE MODALITY OF EACH X CHROMOSOMAL DNAM SITE AND CONDUCTED A SEX-SPECIFIC ASSOCIATION STUDY OF CIGARETTE SMOKING. RESULTS: WE USED A DISCOVERY SAMPLE OF 139 MIDDLE-AGE TWINS, AND THREE REPLICATION SAMPLES OF 78 TWINS, 464 AND 333 UNRELATED INDIVIDUALS INCLUDING 47, 17, 22, AND 89 CURRENT SMOKERS, RESPECTIVELY. AFTER CORRECTION FOR MULTIPLE TESTING, THE TOP SMOKING-RELATED DNAM SITES IN BCOR AND TSC22D3 WERE SIGNIFICANTLY HYPERMETHYLATED AND HYPOMETHYLATED, RESPECTIVELY, AMONG CURRENT SMOKERS. THESE SMOKING-ASSOCIATED SITES WERE REPLICATED WITH META-ANALYSIS P-VALUES OF 9.17 X 10(-12) AND 1.61 X 10(-9). FOR BOTH SITES, THE SMOKING EFFECTS ON METHYLATION LEVELS WERE LARGER IN MALES THAN THAT IN FEMALES. CONCLUSIONS: OUR FINDINGS HIGHLIGHT THE IMPORTANCE OF INVESTIGATING X CHROMOSOME METHYLATION PATTERNS AND THEIR ASSOCIATIONS WITH ENVIRONMENTAL EXPOSURES AND DISEASE PHENOTYPES AND DEMONSTRATE A ROBUST STATISTICAL METHODOLOGY FOR SUCH STUDY. EXISTING EWAS OF HUMAN DISEASES SHOULD INCORPORATE THE X CHROMOSOMAL SITES TO COMPLETE A COMPREHENSIVE EPIGENOME-WIDE SCAN. 2016 9 3057 46 GENOME-WIDE DNA METHYLATION ANALYSIS IN ANKYLOSING SPONDYLITIS IDENTIFIES HLA-B*27 DEPENDENT AND INDEPENDENT DNA METHYLATION CHANGES IN WHOLE BLOOD. BACKGROUND AND OBJECTIVE: ANKYLOSING SPONDYLITIS IS A CHRONIC INFLAMMATORY DISEASE CHARACTERIZED BY INFLAMMATION OF THE SACROILIAC JOINTS AND THE SPINE THAT CAN LEAD TO SIGNIFICANT PAIN, IMMOBILITY, AND DISABILITY. THE ETIOLOGY AND PATHOGENESIS OF ANKYLOSING SPONDYLITIS ARE INCOMPLETELY UNDERSTOOD, THOUGH MOST PATIENTS CARRY THE HLA-B*27 ALLELE. THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE DNA METHYLATION CHANGES IN ANKYLOSING SPONDYLITIS WITH THE GOAL OF REVEALING NOVEL MECHANISTIC INSIGHTS INTO THIS DISEASE. METHODS: GENOME-WIDE DNA METHYLATION ANALYSIS WAS PERFORMED IN WHOLE BLOOD DNA SAMPLES USING THE INFINIUM METHYLATIONEPIC ARRAY IN PATIENTS WITH ANKYLOSING SPONDYLITIS COMPARED TO AGE, SEX, AND RACE MATCHED PATIENTS WITH OSTEOARTHRITIS AS A NON-INFLAMMATORY DISEASE CONTROL. WE STUDIED 24 PATIENTS WITH ANKYLOSING SPONDYLITIS, INCLUDING 12 PATIENTS WHO CARRY HLA-B*27 AND 12 PATIENTS WHO ARE HLA-B*27 NEGATIVE. DNA METHYLATION ANALYSIS WAS PERFORMED WITH ADJUSTMENT FOR BLOOD CELL COMPOSITION IN EACH SAMPLE. RESULTS: WE IDENTIFIED A TOTAL OF 67 DIFFERENTIALLY METHYLATED SITES BETWEEN ANKYLOSING SPONDYLITIS PATIENTS AND OSTEOARTHRITIS CONTROLS. HYPERMETHYLATED GENES FOUND INCLUDED GTPASE-RELATED GENES, WHILE HYPOMETHYLATED GENES INCLUDED HCP5, WHICH ENCODES A LNCRNA WITHIN THE MHC REGION, PREVIOUSLY ASSOCIATED WITH GENETIC RISK FOR PSORIASIS AND TOXIC EPIDERMAL NECROLYSIS. CARRYING HLA-B*27 WAS ASSOCIATED WITH ROBUST HYPOMETHYLATION OF HCP5, TUBULIN FOLDING COFACTOR A (TBCA) AND PHOSPHOLIPASE D FAMILY MEMBER 6 (PLD6) IN ANKYLOSING SPONDYLITIS PATIENTS. HYPOMETHYLATION WITHIN HCP5 INVOLVES A CPG SITE THAT CONTAINS A SINGLE NUCLEOTIDE POLYMORPHISM IN LINKAGE DISEQUILIBRIUM WITH HLA-B*27 AND THAT CONTROLS DNA METHYLATION AT THIS LOCUS IN AN ALLELE-SPECIFIC MANNER. CONCLUSIONS: A GENOME-WIDE DNA METHYLATION ANALYSIS IN ANKYLOSING SPONDYLITIS IDENTIFIED DNA METHYLATION PATTERNS THAT COULD PROVIDE POTENTIAL NOVEL INSIGHTS INTO THIS DISEASE. OUR FINDINGS SUGGEST THAT HLA-B*27 MIGHT PLAY A ROLE IN ANKYLOSING SPONDYLITIS IN PART THROUGH INDUCING EPIGENETIC DYSREGULATION. 2019 10 4256 35 METHYLOMIC MARKERS OF PERSISTENT CHILDHOOD ASTHMA: A LONGITUDINAL STUDY OF ASTHMA-DISCORDANT MONOZYGOTIC TWINS. BACKGROUND: ASTHMA IS THE MOST COMMON CHRONIC INFLAMMATORY DISORDER IN CHILDREN. THE AETIOLOGY OF ASTHMA PATHOLOGY IS COMPLEX AND HIGHLY HETEROGENEOUS, INVOLVING THE INTERPLAY BETWEEN GENETIC AND ENVIRONMENTAL RISK FACTORS THAT IS HYPOTHESIZED TO INVOLVE EPIGENETIC PROCESSES. OUR AIM WAS TO EXPLORE WHETHER METHYLOMIC VARIATION IN EARLY CHILDHOOD IS ASSOCIATED WITH DISCORDANCE FOR ASTHMA SYMPTOMS WITHIN MONOZYGOTIC (MZ) TWIN PAIRS RECRUITED FROM THE ENVIRONMENTAL RISK (E-RISK) LONGITUDINAL TWIN STUDY. WE ALSO AIMED TO IDENTIFY DIFFERENCES IN DNA METHYLATION THAT ARE ASSOCIATED WITH ASTHMA THAT DEVELOPS IN CHILDHOOD AND PERSISTS INTO EARLY ADULTHOOD AS THESE MAY REPRESENT USEFUL PROGNOSTIC BIOMARKERS. RESULTS: WE EXAMINED GENOME-WIDE PATTERNS OF DNA METHYLATION IN BUCCAL CELL SAMPLES COLLECTED FROM 37 MZ TWIN PAIRS DISCORDANT FOR ASTHMA AT AGE 10. DNA METHYLATION AT INDIVIDUAL CPG SITES DEMONSTRATED SIGNIFICANT VARIABILITY WITHIN DISCORDANT MZ TWIN PAIRS WITH THE TOP-RANKED NOMINALLY SIGNIFICANT DIFFERENTIALLY METHYLATED POSITION (DMP) LOCATED IN THE HGSNAT GENE. WE STRATIFIED OUR ANALYSIS BY ASSESSING DNA METHYLATION DIFFERENCES IN A SUB-GROUP OF MZ TWIN PAIRS WHO REMAINED PERSISTENTLY DISCORDANT FOR ASTHMA AT AGE 18. THE TOP-RANKED NOMINALLY SIGNIFICANT DMP ASSOCIATED WITH PERSISTING ASTHMA IS LOCATED IN THE VICINITY OF THE HLX GENE, WHICH HAS BEEN PREVIOUSLY IMPLICATED IN CHILDHOOD ASTHMA. CONCLUSIONS: WE IDENTIFIED DNA METHYLATION DIFFERENCES ASSOCIATED WITH CHILDHOOD ASTHMA IN PERIPHERAL DNA SAMPLES FROM DISCORDANT MZ TWIN PAIRS. OUR DATA SUGGEST THAT DIFFERENCES IN DNA METHYLATION ASSOCIATED WITH CHILDHOOD ASTHMA WHICH PERSISTS INTO EARLY ADULTHOOD ARE DISTINCT FROM THOSE ASSOCIATED WITH ASTHMA WHICH REMITS. 2015 11 972 50 CHRONIC OBSTRUCTIVE PULMONARY DISEASE IS ASSOCIATED WITH EPIGENOME-WIDE DIFFERENTIAL METHYLATION IN BAL LUNG CELLS. DNA METHYLATION PATTERNS IN CHRONIC PULMONARY OBSTRUCTIVE DISEASE (COPD) MIGHT OFFER NEW INSIGHTS INTO DISEASE PATHOGENESIS. TO ASSESS METHYLATION PROFILES IN THE MAIN COPD TARGET ORGAN, WE PERFORMED AN EPIGENOME-WIDE ASSOCIATION STUDY ON BAL CELLS. BRONCHOSCOPIES WERE PERFORMED IN 18 SUBJECTS WITH COPD AND 15 CONTROL SUBJECTS (EX- AND CURRENT SMOKERS). DNA METHYLATION WAS MEASURED USING THE ILLUMINA METHYLATIONEPIC BEADCHIP KIT, COVERING MORE THAN 850,000 CPGS. DIFFERENTIALLY METHYLATED POSITIONS (DMPS) WERE EXAMINED FOR 1) ENRICHMENT IN PATHWAYS AND FUNCTIONAL GENE RELATIONSHIPS USING THE KYOTO ENCYCLOPEDIA OF GENES AND GENOMES AND GENE ONTOLOGY, 2) ACCELERATED AGING USING HORVATH'S EPIGENETIC CLOCK, 3) CORRELATION WITH GENE EXPRESSION, AND 4) COLOCALIZATION WITH GENETIC VARIATION. WE FOUND 1,155 BONFERRONI-SIGNIFICANT (P < 6.74 X 10(-8)) DMPS ASSOCIATED WITH COPD, MANY WITH LARGE EFFECT SIZES. FUNCTIONAL ANALYSIS IDENTIFIED BIOLOGICALLY PLAUSIBLE PATHWAYS AND GENE RELATIONSHIPS, INCLUDING ENRICHMENT FOR TRANSCRIPTION FACTOR ACTIVITY. STRONG CORRELATION WAS FOUND BETWEEN DNA METHYLATION AND CHRONOLOGICAL AGE BUT NOT BETWEEN COPD AND ACCELERATED AGING. FOR 79 UNIQUE DMPS, DNA METHYLATION CORRELATED SIGNIFICANTLY WITH GENE EXPRESSION IN BAL CELLS. THIRTY-NINE PERCENT OF DMPS WERE COLOCALIZED WITH COPD-ASSOCIATED SNPS. TO THE BEST OF OUR KNOWLEDGE, THIS IS THE FIRST EPIGENOME-WIDE ASSOCIATION STUDY OF COPD ON BAL CELLS, AND OUR ANALYSES REVEALED MANY DIFFERENTIAL METHYLATION SITES. INTEGRATION WITH MRNA DATA SHOWED A STRONG FUNCTIONAL READOUT FOR RELEVANT GENES, IDENTIFYING SITES WHERE DNA METHYLATION MIGHT DIRECTLY AFFECT EXPRESSION. ALMOST HALF OF DMPS WERE COLOCATED WITH SNPS IDENTIFIED IN PREVIOUS GENOME-WIDE ASSOCIATION STUDIES OF COPD, SUGGESTING JOINT GENETIC AND EPIGENETIC PATHWAYS RELATED TO DISEASE. 2022 12 3063 41 GENOME-WIDE DNA METHYLATION AND LONG-TERM AMBIENT AIR POLLUTION EXPOSURE IN KOREAN ADULTS. BACKGROUND: AMBIENT AIR POLLUTION IS ASSOCIATED WITH NUMEROUS ADVERSE HEALTH OUTCOMES, BUT THE UNDERLYING MECHANISMS ARE NOT WELL UNDERSTOOD; EPIGENETIC EFFECTS INCLUDING ALTERED DNA METHYLATION COULD PLAY A ROLE. TO EVALUATE ASSOCIATIONS OF LONG-TERM AIR POLLUTION EXPOSURE WITH DNA METHYLATION IN BLOOD, WE CONDUCTED AN EPIGENOME-WIDE ASSOCIATION STUDY IN A KOREAN CHRONIC OBSTRUCTIVE PULMONARY DISEASE COHORT (N = 100 INCLUDING 60 CASES) USING ILLUMINA'S INFINIUM HUMANMETHYLATION450K BEADCHIP. ANNUAL AVERAGE CONCENTRATIONS OF PARTICULATE MATTER