1 4256 127 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 2 2643 39 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 3 5748 45 SOCIAL AND PHYSICAL ENVIRONMENTS EARLY IN DEVELOPMENT PREDICT DNA METHYLATION OF INFLAMMATORY GENES IN YOUNG ADULTHOOD. CHRONIC INFLAMMATION CONTRIBUTES TO A WIDE RANGE OF HUMAN DISEASES, AND ENVIRONMENTS IN INFANCY AND CHILDHOOD ARE IMPORTANT DETERMINANTS OF INFLAMMATORY PHENOTYPES. THE UNDERLYING BIOLOGICAL MECHANISMS CONNECTING EARLY ENVIRONMENTS WITH THE REGULATION OF INFLAMMATION IN ADULTHOOD ARE NOT KNOWN, BUT EPIGENETIC PROCESSES ARE PLAUSIBLE CANDIDATES. WE TESTED THE HYPOTHESIS THAT PATTERNS OF DNA METHYLATION (DNAM) IN INFLAMMATORY GENES IN YOUNG ADULTHOOD WOULD BE PREDICTED BY EARLY LIFE NUTRITIONAL, MICROBIAL, AND PSYCHOSOCIAL EXPOSURES PREVIOUSLY ASSOCIATED WITH LEVELS OF INFLAMMATION. DATA COME FROM A POPULATION-BASED LONGITUDINAL BIRTH COHORT STUDY IN METROPOLITAN CEBU, THE PHILIPPINES, AND DNAM WAS CHARACTERIZED IN WHOLE BLOOD SAMPLES FROM 494 PARTICIPANTS (AGE 20-22 Y). ANALYSES FOCUSED ON PROBES IN 114 TARGET GENES INVOLVED IN THE REGULATION OF INFLAMMATION, AND WE IDENTIFIED 10 SITES ACROSS NINE GENES WHERE THE LEVEL OF DNAM WAS SIGNIFICANTLY PREDICTED BY THE FOLLOWING VARIABLES: HOUSEHOLD SOCIOECONOMIC STATUS IN CHILDHOOD, EXTENDED ABSENCE OF A PARENT IN CHILDHOOD, EXPOSURE TO ANIMAL FECES IN INFANCY, BIRTH IN THE DRY SEASON, OR DURATION OF EXCLUSIVE BREASTFEEDING. TO EVALUATE THE BIOLOGICAL SIGNIFICANCE OF THESE SITES, WE TESTED FOR ASSOCIATIONS WITH A PANEL OF INFLAMMATORY BIOMARKERS MEASURED IN PLASMA OBTAINED AT THE SAME AGE AS DNAM ASSESSMENT. THREE SITES PREDICTED ELEVATED INFLAMMATION, AND ONE SITE PREDICTED LOWER INFLAMMATION, CONSISTENT WITH THE INTERPRETATION THAT LEVELS OF DNAM AT THESE SITES ARE FUNCTIONALLY RELEVANT. THIS PATTERN OF RESULTS POINTS TOWARD DNAM AS A POTENTIALLY IMPORTANT BIOLOGICAL MECHANISM THROUGH WHICH DEVELOPMENTAL ENVIRONMENTS SHAPE INFLAMMATORY PHENOTYPES ACROSS THE LIFE COURSE. 2017 4 1516 42 DNA METHYLATION AS A BIOMARKER OF AGING IN EPIDEMIOLOGIC STUDIES. CANCER IS LARGELY AN AGING DISEASE. ACCELERATED BIOLOGICAL AGING MAY BE THE STRONGEST PREDICTOR OF CANCER AND OTHER CHRONIC DISEASE RISKS. IN THE ABSENCE OF RELIABLE AND QUANTIFIABLE BIOMARKERS OF AGING TO DATE, IT HAS LONG BEEN OBSERVED THAT TUMORIGENESIS SHARES DISTINCT EPIGENETIC ALTERATIONS WITH THE AGING PROCESS. RECENTLY, EPIGENETIC AGE ESTIMATES HAVE BEEN DEVELOPED BASED ON THE AVAILABILITY OF GENOME-WIDE DNA METHYLATION PROFILES, BY APPLYING IN THE PREDICTION FORMULA THE METHYLATION LEVEL AT A SUBSET OF HIGHLY PREDICTIVE METHYLATION SITES, CALLED EPIGENETIC CLOCK. THESE DNA METHYLATION AGE ESTIMATES HAVE PRODUCED REMARKABLY STRONG CORRELATIONS WITH CHRONOLOGICAL AGE, WITH A SMALL DEVIATION AND HIGH REPRODUCIBILITY ACROSS DIFFERENT AGE GROUPS AND STUDY POPULATIONS. MOREOVER, AN INCREASING NUMBER OF EPIDEMIOLOGIC STUDIES HAVE DEMONSTRATED AN INDEPENDENT ASSOCIATION OF DNA METHYLATION AGE OR THE EXTENT OF ACCELERATION WITH MORTALITY AND VARIOUS AGING-RELATED CONDITIONS, EVEN AFTER ACCOUNTING FOR DIFFERENCES IN CHRONOLOGICAL AGE AND OTHER RISK FACTORS. ALTHOUGH EPIGENETIC PROFILES ARE KNOWN TO BE TISSUE-SPECIFIC, BOTH TARGET TISSUE- AND MULTIPLE TISSUE-DERIVED ESTIMATES APPEAR TO PERFORM WELL TO CAPTURE WHAT IS THOUGHT TO BE THE CUMULATIVE EPIGENETIC DRIFT THAT REPRESENTS A MULTIFACTORIAL DEGENERATIVE PROCESS ACROSS TISSUES AND ORGANISMS. FURTHER REFINEMENT OF THE EPIGENETIC AGE ESTIMATES IS ANTICIPATED OVER TIME TO ACCOMMODATE A BETTER TECHNOLOGICAL COVERAGE OF THE METHYLOME AND A BETTER UNDERSTANDING OF THE BIOLOGY UNDERLYING PREDICTIVE REGIONS. EPIDEMIOLOGIC PRINCIPLES WILL REMAIN CRITICAL FOR THE EVALUATION OF RESEARCH FINDINGS INVOLVING, FOR EXAMPLE, DIFFERENT STUDY POPULATIONS, DESIGN, FOLLOW-UP TIME, AND QUALITY OF COVARIATE DATA. OVERALL, THE EPIGENETIC AGE ESTIMATES ARE AN EXCITING DEVELOPMENT WITH USEFUL IMPLICATIONS FOR BIOMEDICAL RESEARCH OF HEALTHY AGING AND DISEASE PREVENTION AND CONTROL. 2018 5 2622 43 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 6 2411 32 EPIGENETIC SCORES FOR THE CIRCULATING PROTEOME AS TOOLS FOR DISEASE PREDICTION. PROTEIN BIOMARKERS HAVE BEEN IDENTIFIED ACROSS MANY AGE-RELATED MORBIDITIES. HOWEVER, CHARACTERISING EPIGENETIC INFLUENCES COULD FURTHER INFORM DISEASE PREDICTIONS. HERE, WE LEVERAGE EPIGENOME-WIDE DATA TO STUDY LINKS BETWEEN THE DNA METHYLATION (DNAM) SIGNATURES OF THE CIRCULATING PROTEOME AND INCIDENT DISEASES. USING DATA FROM FOUR COHORTS, WE TRAINED AND TESTED EPIGENETIC SCORES (EPISCORES) FOR 953 PLASMA PROTEINS, IDENTIFYING 109 SCORES THAT EXPLAINED BETWEEN 1% AND 58% OF THE VARIANCE IN PROTEIN LEVELS AFTER ADJUSTING FOR KNOWN PROTEIN QUANTITATIVE TRAIT LOCI (PQTL) GENETIC EFFECTS. BY PROJECTING THESE EPISCORES INTO AN INDEPENDENT SAMPLE (GENERATION SCOTLAND; N = 9537) AND RELATING THEM TO INCIDENT MORBIDITIES OVER A FOLLOW-UP OF 14 YEARS, WE UNCOVERED 137 EPISCORE-DISEASE ASSOCIATIONS. THESE ASSOCIATIONS WERE LARGELY INDEPENDENT OF IMMUNE CELL PROPORTIONS, COMMON LIFESTYLE AND HEALTH FACTORS, AND BIOLOGICAL AGING. NOTABLY, WE FOUND THAT OUR DIABETES-ASSOCIATED EPISCORES HIGHLIGHTED PREVIOUS TOP BIOMARKER ASSOCIATIONS FROM PROTEOME-WIDE ASSESSMENTS OF DIABETES. THESE EPISCORES FOR PROTEIN LEVELS CAN THEREFORE BE A VALUABLE RESOURCE FOR DISEASE PREDICTION AND RISK STRATIFICATION. 2022 7 2047 30 EPIGENETIC CLOCKS MAY COME OUT OF RHYTHM-IMPLICATIONS FOR THE ESTIMATION OF CHRONOLOGICAL AGE IN FORENSIC CASEWORK. THERE IS A GROWING PERCEPTION THAT DNA METHYLATION MAY BE INFLUENCED BY EXOGENOUS AND ENDOGENOUS PARAMETERS. KNOWLEDGE OF THESE FACTORS IS OF GREAT RELEVANCE FOR THE INTERPRETATION OF DNA-METHYLATION DATA FOR THE ESTIMATION OF CHRONOLOGICAL AGE IN FORENSIC CASEWORK. WE PERFORMED A LITERATURE REVIEW TO IDENTIFY PARAMETERS, WHICH MIGHT BE OF RELEVANCE FOR THE PREDICTION OF CHRONOLOGICAL AGE BASED ON DNA METHYLATION. THE QUALITY OF AGE PREDICTIONS MIGHT PARTICULARLY BE INFLUENCED BY LIFETIME ADVERSITIES (CHRONIC STRESS, TRAUMA/POST-TRAUMATIC STRESS DISORDER (PTSD), VIOLENCE, LOW SOCIOECONOMIC STATUS/EDUCATION), CANCER, OBESITY AND RELATED DISEASES, INFECTIOUS DISEASES (ESPECIALLY HIV AND CYTOMEGALOVIRUS (CMV) INFECTIONS), SEX, ETHNICITY AND EXPOSURE TO TOXINS (ALCOHOL, SMOKING, AIR POLLUTION, PESTICIDES). SUCH FACTORS MAY ALTER THE DNA METHYLATION PATTERN AND MAY EXPLAIN THE PARTLY HIGH DEVIATIONS BETWEEN EPIGENETIC AGE AND CHRONOLOGICAL AGE IN SINGLE CASES (DESPITE OF LOW MEAN ABSOLUTE DEVIATIONS) THAT CAN ALSO BE OBSERVED WITH "EPIGENETIC CLOCKS" COMPRISING A HIGH NUMBER OF CPG SITES. SO FAR, ONLY FEW PUBLICATIONS DEALING WITH FORENSIC AGE ESTIMATION ADDRESS THESE CONFOUNDING FACTORS. FUTURE RESEARCH SHOULD FOCUS ON THE IDENTIFICATION OF FURTHER RELEVANT CONFOUNDING FACTORS AND THE DEVELOPMENT OF MODELS THAT ARE "ROBUST" AGAINST THE INFLUENCE OF SUCH BIOLOGICAL FACTORS BY SYSTEMATIC INVESTIGATIONS UNDER TARGETED INCLUSION OF DIVERSE AND DEFINED COHORTS. 2020 8 3557 36 IMPACT OF BMI AND WAIST CIRCUMFERENCE ON EPIGENOME-WIDE DNA METHYLATION AND IDENTIFICATION OF EPIGENETIC BIOMARKERS IN BLOOD: AN EWAS IN MULTI-ETHNIC ASIAN INDIVIDUALS. BACKGROUND: THE PREVALENCE OF OBESITY AND ITS RELATED CHRONIC DISEASES HAVE BEEN INCREASING ESPECIALLY IN ASIAN COUNTRIES. OBESITY-RELATED GENETIC VARIANTS HAVE BEEN IDENTIFIED, BUT THESE EXPLAIN LITTLE OF THE VARIATION IN BMI. RECENT STUDIES REPORTED ASSOCIATIONS BETWEEN DNA METHYLATION AND OBESITY, MOSTLY IN NON-ASIAN POPULATIONS. METHODS: WE PERFORMED AN EPIGENOME-WIDE ASSOCIATION STUDY (EWAS) ON GENERAL ADIPOSITY (BODY MASS INDEX, BMI) AND ABDOMINAL ADIPOSITY (WAIST CIRCUMFERENCE, WC) IN 409 MULTI-ETHNIC ASIAN INDIVIDUALS AND REPLICATED BMI AND WAIST-ASSOCIATED DNA METHYLATION CPGS IDENTIFIED IN OTHER POPULATIONS. THE CROSS-LAGGED PANEL MODEL AND MENDELIAN RANDOMIZATION WERE USED TO ASSESS THE TEMPORAL RELATIONSHIP BETWEEN METHYLATION AND BMI. THE TEMPORAL RELATIONSHIP BETWEEN THE IDENTIFIED CPGS AND INFLAMMATION AND METABOLIC MARKERS WAS ALSO EXAMINED. RESULTS: EWAS IDENTIFIED 116 DNA METHYLATION CPGS INDEPENDENTLY ASSOCIATED WITH BMI AND EIGHT INDEPENDENTLY ASSOCIATED WITH WC AT FALSE DISCOVERY RATE P(FDR) < 0.05 IN 409 ASIAN SAMPLES. WE REPLICATED 110 BMI-ASSOCIATED CPGS PREVIOUSLY REPORTED IN EUROPEANS AND IDENTIFIED SIX NOVEL BMI-ASSOCIATED CPGS AND TWO NOVEL WC-ASSOCIATED CPGS. WE OBSERVED HIGH CONSISTENCY IN ASSOCIATION DIRECTION OF EFFECT COMPARED TO STUDIES IN OTHER POPULATIONS. CAUSAL RELATIONSHIP ANALYSES INDICATED THAT BMI WAS MORE LIKELY TO BE THE CAUSE OF DNA METHYLATION ALTERATION, RATHER THAN THE CONSEQUENCE. THE CAUSAL ANALYSES USING BMI-ASSOCIATED METHYLATION RISK SCORE ALSO SUGGESTED THAT HIGHER LEVELS OF THE INFLAMMATION MARKER IL-6 WERE LIKELY THE CONSEQUENCE OF METHYLATION CHANGE. CONCLUSION: OUR STUDY PROVIDES EVIDENCE OF AN ASSOCIATION BETWEEN OBESITY AND DNA METHYLATION IN MULTI-ETHNIC ASIANS AND SUGGESTS THAT OBESITY CAN DRIVE METHYLATION CHANGE. THE RESULTS ALSO SUGGESTED POSSIBLE CAUSAL INFLUENCE THAT OBESITY-RELATED METHYLATION CHANGES MIGHT HAVE ON INFLAMMATION AND LIPOPROTEIN LEVELS. 2021 9 6112 36 THE EPIGENETIC CLOCK AS A PREDICTOR OF DISEASE AND MORTALITY RISK: A SYSTEMATIC REVIEW AND META-ANALYSIS. BACKGROUND: AGEING IS ONE OF THE PRINCIPAL RISK FACTORS FOR MANY CHRONIC DISEASES. HOWEVER, THERE IS CONSIDERABLE BETWEEN-PERSON VARIATION IN THE RATE OF AGEING AND INDIVIDUAL DIFFERENCES IN THEIR SUSCEPTIBILITY TO DISEASE AND DEATH. EPIGENETIC MECHANISMS MAY PLAY A ROLE IN HUMAN AGEING, AND DNA METHYLATION AGE BIOMARKERS MAY BE GOOD PREDICTORS OF AGE-RELATED DISEASES AND MORTALITY RISK. THE AIMS OF THIS SYSTEMATIC REVIEW WERE TO IDENTIFY AND SYNTHESISE THE EVIDENCE FOR AN ASSOCIATION BETWEEN PERIPHERALLY MEASURED DNA METHYLATION AGE AND LONGEVITY, AGE-RELATED DISEASE, AND MORTALITY RISK. METHODS: A SYSTEMATIC SEARCH WAS CONDUCTED IN LINE WITH THE PREFERRED REPORTING ITEMS FOR SYSTEMATIC REVIEWS AND META-ANALYSES (PRISMA) GUIDELINES. USING RELEVANT SEARCH TERMS, MEDLINE, EMBASE, COCHRANE CENTRAL REGISTER OF CONTROLLED TRIALS, AND PSYCHINFO DATABASES WERE SEARCHED TO IDENTIFY ARTICLES MEETING THE INCLUSION CRITERIA. STUDIES WERE ASSESSED FOR BIAS USING JOANNA BRIGGS INSTITUTE CRITICAL APPRAISAL CHECKLISTS. DATA WAS EXTRACTED FROM STUDIES MEASURING AGE ACCELERATION AS A PREDICTOR OF AGE-RELATED DISEASES, MORTALITY OR LONGEVITY, AND THE FINDINGS FOR SIMILAR OUTCOMES COMPARED. USING REVIEW MANAGER 5.3 SOFTWARE, TWO META-ANALYSES (ONE PER EPIGENETIC CLOCK) WERE CONDUCTED ON STUDIES MEASURING ALL-CAUSE MORTALITY. RESULTS: TWENTY-THREE RELEVANT ARTICLES WERE IDENTIFIED, INCLUDING A TOTAL OF 41,607 PARTICIPANTS. FOUR STUDIES FOCUSED ON AGEING AND LONGEVITY, 11 ON AGE-RELATED DISEASE (CANCER, CARDIOVASCULAR DISEASE, AND DEMENTIA), AND 11 ON MORTALITY. THERE WAS SOME, ALTHOUGH INCONSISTENT, EVIDENCE FOR AN ASSOCIATION BETWEEN INCREASED DNA METHYLATION AGE AND RISK OF DISEASE. META-ANALYSES INDICATED THAT EACH 5-YEAR INCREASE IN DNA METHYLATION AGE WAS ASSOCIATED AN 8 TO 15% INCREASED RISK OF MORTALITY. CONCLUSION: DUE TO THE SMALL NUMBER OF STUDIES AND HETEROGENEITY IN STUDY DESIGN AND OUTCOMES, THE ASSOCIATION BETWEEN DNA METHYLATION AGE AND AGE-RELATED DISEASE AND LONGEVITY IS INCONCLUSIVE. INCREASED EPIGENETIC AGE WAS ASSOCIATED WITH MORTALITY RISK, BUT POSITIVE PUBLICATION BIAS NEEDS TO BE CONSIDERED. FURTHER RESEARCH IS NEEDED TO DETERMINE THE EXTENT TO WHICH DNA METHYLATION AGE CAN BE USED AS A CLINICAL BIOMARKER. 2019 10 120 33 A SYSTEMATIC REVIEW OF CHILDHOOD MALTREATMENT AND DNA METHYLATION: CANDIDATE GENE AND EPIGENOME-WIDE APPROACHES. CHILDHOOD MALTREATMENT IS A MAJOR RISK FACTOR FOR CHRONIC AND SEVERE MENTAL AND PHYSICAL HEALTH PROBLEMS ACROSS THE LIFESPAN. INCREASING EVIDENCE SUPPORTS THE HYPOTHESIS THAT MALTREATMENT IS ASSOCIATED WITH EPIGENETIC CHANGES THAT MAY SUBSEQUENTLY SERVE AS MECHANISMS OF DISEASE. THE CURRENT REVIEW USES A SYSTEMATIC APPROACH TO IDENTIFY AND SUMMARIZE THE LITERATURE RELATED TO CHILDHOOD MALTREATMENT AND ALTERATIONS IN DNA METHYLATION IN HUMANS. A TOTAL OF 100 EMPIRICAL ARTICLES WERE IDENTIFIED IN OUR SYSTEMATIC REVIEW OF RESEARCH PUBLISHED PRIOR TO OR DURING MARCH 2020, INCLUDING STUDIES THAT FOCUSED ON CANDIDATE GENES AND STUDIES THAT LEVERAGED EPIGENOME-WIDE DATA IN BOTH CHILDREN AND ADULTS. THEMES ARISING FROM THE LITERATURE, INCLUDING CONSISTENT AND INCONSISTENT PATTERNS OF RESULTS, ARE PRESENTED. SEVERAL DIRECTIONS FOR FUTURE RESEARCH, INCLUDING IMPORTANT METHODOLOGICAL CONSIDERATIONS FOR FUTURE STUDY DESIGN, ARE DISCUSSED. TAKEN TOGETHER, THE LITERATURE ON CHILDHOOD MALTREATMENT AND DNA METHYLATION UNDERSCORES THE COMPLEXITY OF TRANSACTIONS BETWEEN THE ENVIRONMENT AND BIOLOGY ACROSS DEVELOPMENT. 2021 11 6761 36 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 12 2148 38 EPIGENETIC MARKERS OF RENAL FUNCTION IN AFRICAN AMERICANS. CHRONIC KIDNEY DISEASE (CKD) IS AN INCREASING CONCERN IN THE UNITED STATES DUE TO ITS RAPIDLY RISING PREVALENCE, PARTICULARLY AMONG AFRICAN AMERICANS. EPIGENETIC DNA METHYLATION MARKERS ARE BECOMING IMPORTANT BIOMARKERS OF CHRONIC DISEASES SUCH AS CKD. TO BETTER UNDERSTAND HOW THESE METHYLATION MARKERS PLAY A ROLE IN KIDNEY FUNCTION, WE MEASURED 26,428 DNA METHYLATION SITES IN 972 AFRICAN AMERICANS FROM THE GENETIC EPIDEMIOLOGY NETWORK OF ARTERIOPATHY (GENOA) STUDY. WE THEN EVALUATED (1) WHETHER EPIGENETIC MARKERS ARE ASSOCIATED WITH ESTIMATED GLOMERULAR FILTRATION RATE (EGFR), (2) WHETHER THE SIGNIFICANTLY ASSOCIATED MARKERS ARE ALSO ASSOCIATED WITH TRADITIONAL RISK FACTORS AND/OR NOVEL BIOMARKERS FOR EGFR, AND (3) HOW MUCH ADDITIONAL VARIATION IN EGFR IS EXPLAINED BY EPIGENETIC MARKERS BEYOND ESTABLISHED RISK FACTORS AND BIOMARKERS. THE MAJORITY OF METHYLATION MARKERS MOST SIGNIFICANTLY ASSOCIATED WITH EGFR (24 OUT OF THE TOP 30) APPEARED TO FUNCTION, AT LEAST IN PART, THROUGH PATHWAYS RELATED TO AGING, INFLAMMATION, OR CHOLESTEROL. HOWEVER, SIX EPIGENETIC MARKERS WERE STILL ABLE TO SIGNIFICANTLY PREDICT EGFR AFTER ADJUSTMENT FOR OTHER RISK FACTORS. THIS WORK SHOWS THAT EPIGENETIC MARKERS MAY OFFER VALUABLE NEW INSIGHT INTO THE COMPLEX PATHOPHYSIOLOGY OF CKD IN AFRICAN AMERICANS. 2013 13 3027 34 GENETICS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A COMPLEX DISEASE WITH MULTIFACTORIAL BACKGROUND, BASED ON THE INTERACTION OF ENVIRONMENTAL AND GENETIC FACTORS. ENVIRONMENTAL FACTORS ARE CLEARLY RELATED TO THE DEVELOPMENT OF THE DISEASE. HOWEVER, FAMILY AND TWIN STUDIES SUGGESTED GENETICS FACTORS TO BE ONE OF THE IMPORTANT DETERMINANTS FOR THE DEVELOPMENT OF COPD. DIFFERENT APPROACHES HAVE BEEN USED TO IDENTIFY GENES OF INTEREST. GENOMEWIDE LINKAGE ANALYSIS FOUND AREAS OF INTEREST ON DIFFERENT CHROMOSOMES, WITH SOME GENES LOCATED IN THIS REGIONS BEING IDENTIFIED AND REPLICATED AS SUSCEPTIBILITY GENES. NUMEROUS OF CANDIDATE GENES THAT COULD BE LINKED TO DISEASE PATHOGENESIS HAVE BEEN IMPLICATED IN COPD GENETICS. HOWEVER, THE CANDIDATE GENE APPROACH IS OFTEN LIMITED BY INCONSISTENT RESULTS IN OTHER STUDY POPULATIONS. RECENTLY, A COMBINATION OF DIFFERENT METHODS IS USED GIVING MORE EVIDENCE FOR SOME CANDIDATE GENES, INCLUDING TGFBETA-1, SURFACTANT, SERPINE2 AND MICROSOMAL EPOXIDE HYDROLASE. IN THE FUTURE ONGOING EXACT PHENOTYPE DEFINITION, COMBINATION OF SEVERAL APPROACHES, GENOME-WIDE ASSOCIATION STUDIES AND ANIMAL MODEL GENETICS WILL LEAD TO NEW INSIGHTS INTO THE GENETICS OF COPD, WITH EPIGENETIC FACTORS NEEDS TO BE FURTHER INVESTIGATED AND CONSIDERED IN CONCERT WITH GENETIC FINDINGS. 2007 14 5882 38 SYSTEMATIC REVIEW OF LUNG FUNCTION AND COPD WITH PERIPHERAL BLOOD DNA METHYLATION IN POPULATION BASED STUDIES. BACKGROUND: EPIGENETIC VARIATIONS IN PERIPHERAL BLOOD HAVE POTENTIAL AS BIOMARKERS FOR DISEASE. THIS SYSTEMATIC REVIEW ASSESSES THE ASSOCIATION OF LUNG FUNCTION AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) WITH DNA METHYLATION PROFILES IN PERIPHERAL BLOOD FROM POPULATION-BASED STUDIES. METHODS: ONLINE DATABASES MEDLINE, EMBASE, AND WEB OF SCIENCE WERE SEARCHED. GOOGLE SCHOLAR WAS SEARCHED TO IDENTIFY GREY LITERATURE. AFTER REMOVING DUPLICATE ARTICLES, 1155 ARTICLES WERE INDEPENDENTLY SCREENED BY TWO INVESTIGATORS. PEER REVIEWED REPORTS ON POPULATION-BASED STUDIES THAT EXAMINED PERIPHERAL BLOOD DNA METHYLATION IN PARTICIPANTS WITH MEASURED LUNG FUNCTION (FEV1, FEV1/FVC RATIO) OR KNOWN COPD STATUS WERE SELECTED FOR FULL-TEXT REVIEW. SIX ARTICLES WERE SUITABLE FOR INCLUSION. INFORMATION REGARDING STUDY CHARACTERISTICS, DESIGNS, METHODOLOGIES AND CONCLUSIONS WAS EXTRACTED. A NARRATIVE SYNTHESIS WAS PERFORMED BASED ON PUBLISHED RESULTS. RESULTS: THREE OF THE SIX ARTICLES ASSESSED THE ASSOCIATION OF COPD WITH DNA METHYLATION, AND TWO OF THESE ALSO INCLUDED ASSOCIATIONS WITH LUNG FUNCTION. OVERALL, FIVE REPORTS EXAMINED THE ASSOCIATION OF LUNG FUNCTION WITH DNA METHYLATION PROFILES. FIVE OF THE SIX ARTICLES REPORTED 'SIGNIFICANT' RESULTS. HOWEVER, NO CONSISTENT CPG SITES WERE IDENTIFIED ACROSS STUDIES FOR COPD STATUS OR LUNG FUNCTION VALUES. CONCLUSIONS: DNA METHYLATION PATTERNS IN PERIPHERAL BLOOD FROM INDIVIDUALS WITH REDUCED LUNG FUNCTION OR COPD MAY BE DIFFERENT TO THOSE IN PEOPLE WITH NORMAL LUNG FUNCTION. HOWEVER, THIS SYSTEMATIC REVIEW DID NOT FIND ANY CONSISTENT ASSOCIATIONS OF LUNG FUNCTION OR COPD WITH DIFFERENTIALLY METHYLATED CPG SITES. LARGE STUDIES WITH A LONGITUDINAL DESIGN TO ADDRESS REVERSE CAUSALITY MAY PROVE A MORE FRUITFUL AREA OF RESEARCH. TRIAL REGISTRATION: PROSPERO 2016: CRD42016037352 . 2017 15 3653 25 INDIVIDUAL EPIGENETIC VARIATION: WHEN, WHY, AND SO WHAT? EPIGENETICS PROVIDES A POTENTIAL EXPLANATION FOR HOW ENVIRONMENTAL FACTORS MODIFY THE RISK FOR COMMON DISEASES AMONG INDIVIDUALS. INTERINDIVIDUAL VARIATION IN DNA METHYLATION AND EPIGENETIC REGULATION HAS BEEN REPORTED AT SPECIFIC GENOMIC REGIONS INCLUDING TRANSPOSABLE ELEMENTS, GENOMICALLY IMPRINTED GENES AND THE 'INACTIVE' X CHROMOSOMES IN FEMALES. WE CURRENTLY HAVE A VERY POOR UNDERSTANDING OF THE FACTORS THAT CONTRIBUTE TO INTERINDIVIDUAL EPIGENETIC VARIATION. IN PARTICULAR, IT IS IMPORTANT TO UNDERSTAND WHEN DURING THE LIFE CYCLE EPIGENETIC VARIATION ARISES, WHY EPIGENETIC REGULATION VARIES AMONG INDIVIDUALS, AND WHETHER EPIGENETIC INTERINDIVIDUALITY AFFECTS SUSCEPTIBILITY TO DIET-RELATED CHRONIC DISEASE. IN THIS REVIEW WE WILL SUMMARIZE CURRENT PROGRESS TOWARD ANSWERING THESE QUESTIONS. 2008 16 2677 32 EVALUATING THE CHALLENGES AND REPRODUCIBILITY OF STUDIES INVESTIGATING DNA METHYLATION SIGNATURES OF PSYCHOLOGICAL STRESS. PSYCHOLOGICAL STRESS CAN INCREASE THE RISK OF A WIDE RANGE OF NEGATIVE HEALTH OUTCOMES. STUDIES HAVE BEEN COMPLETED TO DETERMINE IF DNA METHYLATION CHANGES OCCUR IN THE HUMAN BRAIN BECAUSE OF STRESS AND ARE ASSOCIATED WITH LONG-TERM EFFECTS AND DISEASE, BUT RESULTS HAVE BEEN INCONSISTENT. HUMAN CANDIDATE GENE STUDIES (150) AND EPIGENOME-WIDE ASSOCIATION STUDIES (67) WERE SYSTEMATICALLY EVALUATED TO ASSESS HOW DNA METHYLATION IS IMPACTED BY STRESS DURING THE PRENATAL PERIOD, EARLY CHILDHOOD AND ADULTHOOD. THE ASSOCIATION BETWEEN DNA METHYLATION OF NR3C1 EXON 1F AND CHILD MALTREATMENT AND EARLY LIFE ADVERSITY WAS WELL DEMONSTRATED, BUT OTHER GENES DID NOT EXHIBIT A CLEAR ASSOCIATION. THE REPRODUCIBILITY OF INDIVIDUAL CPG SITES IN EPIGENOME-WIDE ASSOCIATION STUDIES WAS ALSO POOR. HOWEVER, BIOLOGICAL PATHWAYS, INCLUDING STRESS RESPONSE, BRAIN DEVELOPMENT AND IMMUNITY, HAVE BEEN CONSISTENTLY IDENTIFIED ACROSS DIFFERENT STRESSORS THROUGHOUT THE LIFE SPAN. FUTURE STUDIES WOULD BENEFIT FROM THE INCREASED SAMPLE SIZE, LONGITUDINAL DESIGN, STANDARDIZED METHODOLOGY, OPTIMAL QUALITY CONTROL, AND IMPROVED STATISTICAL PROCEDURES. 2022 17 2075 39 EPIGENETIC DIFFERENCES IN INFLAMMATION GENES OF MONOZYGOTIC TWINS ARE RELATED TO PARENT-CHILD EMOTIONAL AVAILABILITY AND HEALTH. THE INFLAMMATORY RESPONSE IS AN IMMUNE DEFENSE ENGAGED IMMEDIATELY AFTER INJURY OR INFECTION. CHRONIC INFLAMMATION CAN BE DELETERIOUS FOR VARIOUS HEALTH OUTCOMES AND IS CHARACTERIZED BY HIGH LEVELS OF PRO-INFLAMMATORY MARKERS SUCH AS C-REACTIVE PROTEIN (CRP), INTERLEUKIN 6 (IL-6), AND TUMOR NECROSIS FACTOR ALPHA (TNF-ALPHA). A LARGE BODY OF RESEARCH DEMONSTRATES THESE INFLAMMATORY MARKERS ARE RESPONSIVE TO STRESS AND QUALITY OF SOCIAL RELATIONSHIPS THROUGHOUT THE LIFESPAN. FOR EXAMPLE, THE QUALITY OF THE EARLY PARENTAL BOND PREDICTS VARIOUS HEALTH OUTCOMES AND MAY BE DRIVEN BY CHANGES IN IMMUNE FUNCTION. EPIGENETIC PROCESSES, SUCH AS DNA METHYLATION, MAY BE ONE MECHANISM BY WHICH EARLY SOCIAL EXPERIENCES SHAPE IMMUNE FUNCTIONING. THE PRESENT STUDY USED A MONOZYGOTIC TWIN DIFFERENCE DESIGN TO ASSESS IF MOTHER-REPORTED EMOTIONAL AVAILABILITY AT 1 YEAR AND 2.5 YEARS PREDICTED IMMUNE GENE METHYLATION AT 8 YEARS OF AGE. FURTHER, WE ASSESSED IF INFLAMMATION GENE METHYLATION WAS RELATED TO GENERAL HEALTH PROBLEMS (E.G. INFECTIONS, ALLERGIES, ETC.). WE FOUND THAT MOTHER-REPORTED EMOTIONAL AVAILABILITY AT 1 YEAR, BUT NOT 2.5 YEARS, WAS RELATED TO METHYLATION OF VARIOUS IMMUNE GENES IN MONOZYGOTIC TWINS. FURTHERMORE, TWIN PAIRS DISCORDANT IN HEALTH PROBLEMS HAVE MORE DIFFERENCE IN IMMUNE GENE METHYLATION COMPARED TO TWIN PAIRS CONCORDANT FOR HEALTH PROBLEMS, SUGGESTING THAT METHYLATION OF IMMUNE GENES MAY HAVE FUNCTIONAL CONSEQUENCES FOR GENERAL HEALTH. THESE RESULTS SUGGEST THAT THE EMOTIONAL COMPONENT OF ATTACHMENT QUALITY DURING INFANCY CONTRIBUTES TO IMMUNE EPIGENETIC PROFILES IN CHILDHOOD, WHICH MAY INFLUENCE GENERAL HEALTH. 2020 18 527 36 ASTHMA AND THE MISSING HERITABILITY PROBLEM: NECESSITY FOR MULTIOMICS APPROACHES IN DETERMINING ACCURATE RISK PROFILES. ASTHMA IS RANKED AMONG THE MOST COMMON CHRONIC CONDITIONS AND HAS BECOME A SIGNIFICANT PUBLIC HEALTH ISSUE DUE TO THE RECENT AND RAPID INCREASE IN ITS PREVALENCE. INVESTIGATIONS INTO THE UNDERLYING GENETIC FACTORS PREDICT A HERITABLE COMPONENT FOR ITS INCIDENCE, ESTIMATED BETWEEN 35% AND 90% OF CAUSATION. DESPITE THE APPLICATION OF LARGE-SCALE GENOME-WIDE ASSOCIATION STUDIES (GWAS) AND ADMIXTURE MAPPING APPROACHES, THE PROPORTION OF VARIANTS IDENTIFIED ACCOUNTS FOR LESS THAN 15% OF THE OBSERVED HERITABILITY OF THE DISEASE. THE DISCREPANCY BETWEEN THE PREDICTED HERITABLE COMPONENT OF DISEASE AND THE PROPORTION OF HERITABILITY MAPPED TO THE CURRENTLY IDENTIFIED SUSCEPTIBILITY LOCI HAS BEEN TERMED THE 'MISSING HERITABILITY PROBLEM.' HERE, WE EXAMINE RECENT STUDIES INVOLVING BOTH THE ANALYSIS OF GENETICALLY ENCODED FEATURES THAT CONTRIBUTE TO ASTHMA AND ALSO THE ROLE OF NON-ENCODED HERITABLE CHARACTERISTICS, INCLUDING EPIGENETIC, ENVIRONMENTAL, AND DEVELOPMENTAL ASPECTS OF DISEASE. THE IMPORTANCE OF VERTICAL MATERNAL MICROBIOME TRANSFER AND THE INFLUENCE OF MATERNAL IMMUNE FACTORS ON FETAL CONDITIONING IN THE INHERITANCE OF DISEASE ARE ALSO DISCUSSED. IN ORDER TO HIGHLIGHT THE BROAD ARRAY OF BIOLOGICAL INPUTS THAT CONTRIBUTE TO THE SUM OF HERITABLE RISK FACTORS ASSOCIATED WITH ALLERGIC DISEASE INCIDENCE THAT, TOGETHER, CONTRIBUTE TO THE INDUCTION OF A PRO-ATOPIC STATE. CURRENTLY, THERE IS A NEED TO DEVELOP IN-DEPTH MODELS OF ASTHMA RISK FACTORS TO OVERCOME THE LIMITATIONS ENCOUNTERED IN THE INTERPRETATION OF GWAS RESULTS IN ISOLATION, WHICH HAVE RESULTED IN THE MISSING HERITABILITY PROBLEM. HENCE, MULTIOMICS ANALYSES NEED TO BE ESTABLISHED CONSIDERING GENETIC, EPIGENETIC, AND FUNCTIONAL DATA TO CREATE A TRUE SYSTEMS BIOLOGY-BASED APPROACH FOR ANALYZING THE REGULATORY PATHWAYS THAT UNDERLIE THE INHERITANCE OF ASTHMA AND TO DEVELOP ACCURATE RISK PROFILES FOR DISEASE. 2022 19 560 26 BACK TO THE FUTURE: EPIGENETIC CLOCK PLASTICITY TOWARDS HEALTHY AGING. AGING IS THE MOST IMPORTANT RISK FACTOR FOR MAJOR HUMAN LIFESTYLE DISEASES, INCLUDING CANCER, NEUROLOGICAL AND CARDIOMETABOLIC DISORDERS. DUE TO THE COMPLEX INTERPLAY BETWEEN GENETICS, LIFESTYLE AND ENVIRONMENTAL FACTORS, SOME INDIVIDUALS SEEM TO AGE FASTER THAN OTHERS, WHEREAS CENTENARIANS SEEM TO HAVE A SLOWER AGING PROCESS. THEREFORE, A BIOCHEMICAL BIOMARKER REFLECTING THE RELATIVE BIOLOGICAL AGE WOULD BE HELPFUL TO PREDICT AN INDIVIDUAL'S HEALTH STATUS AND AGING DISEASE RISK. ALTHOUGH IT IS ALREADY KNOWN FOR YEARS THAT CUMULATIVE EPIGENETIC CHANGES OCCUR UPON AGING, DNA METHYLATION PATTERNS WERE ONLY RECENTLY USED TO CONSTRUCT AN EPIGENETIC CLOCK PREDICTOR FOR BIOLOGICAL AGE, WHICH IS A MEASURE OF HOW WELL YOUR BODY FUNCTIONS COMPARED TO YOUR CHRONOLOGICAL AGE. MOREOVER, THE EPIGENETIC DNA METHYLATION CLOCK SIGNATURE IS INCREASINGLY APPLIED AS A BIOMARKER TO ESTIMATE AGING DISEASE SUSCEPTIBILITY AND MORTALITY RISK. FINALLY, THE EPIGENETIC CLOCK SIGNATURE COULD BE USED AS A LIFESTYLE MANAGEMENT TOOL TO MONITOR HEALTHY AGING, TO EVALUATE PREVENTIVE INTERVENTIONS AGAINST CHRONIC AGING DISORDERS AND TO EXTEND HEALTHY LIFESPAN. DISSECTING THE MECHANISM OF THE EPIGENETIC AGING CLOCK WILL YIELD VALUABLE INSIGHTS INTO THE AGING PROCESS AND HOW IT CAN BE MANIPULATED TO IMPROVE HEALTH SPAN. 2018 20 2955 29 GENETIC AND EPIGENETIC FACTORS INFLUENCING CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) HAS BECOME A SERIOUS PUBLIC HEALTH PROBLEM BECAUSE OF ITS ASSOCIATED MORBIDITY, PREMATURE MORTALITY, AND ATTENDANT HEALTHCARE COSTS. THE RISING NUMBER OF PERSONS WITH CKD IS LINKED WITH THE AGING POPULATION STRUCTURE AND AN INCREASED PREVALENCE OF DIABETES, HYPERTENSION, AND OBESITY. THERE IS AN INHERITED RISK ASSOCIATED WITH DEVELOPING CKD, AS EVIDENCED BY FAMILIAL CLUSTERING AND DIFFERING PREVALENCE RATES ACROSS ETHNIC GROUPS. PREVIOUS STUDIES TO DETERMINE THE INHERITED RISK FACTORS FOR CKD RARELY IDENTIFIED GENETIC VARIANTS THAT WERE ROBUSTLY REPLICATED. HOWEVER, IMPROVEMENTS IN GENOTYPING TECHNOLOGIES AND ANALYTIC METHODS ARE NOW HELPING TO IDENTIFY PROMISING GENETIC LOCI AIDED BY INTERNATIONAL COLLABORATION AND MULTICONSORTIA EFFORTS. MORE RECENTLY, EPIGENETIC MODIFICATIONS HAVE BEEN PROPOSED TO PLAY A ROLE IN BOTH THE INHERITED SUSCEPTIBILITY TO CKD AND, IMPORTANTLY, TO EXPLAIN HOW THE ENVIRONMENT DYNAMICALLY INTERACTS WITH THE GENOME TO ALTER AN INDIVIDUAL'S DISEASE RISK. GENOME-WIDE, EPIGENOME-WIDE, AND WHOLE TRANSCRIPTOME STUDIES HAVE BEEN PERFORMED, AND OPTIMAL APPROACHES FOR INTEGRATIVE ANALYSIS ARE BEING DEVELOPED. THIS REVIEW SUMMARIZES RECENT RESEARCH AND THE CURRENT STATUS OF GENETIC AND EPIGENETIC RISK FACTORS INFLUENCING CKD USING POPULATION-BASED INFORMATION. 2014