1 3743 205 INSIGHTS FROM GENOMIC STUDIES ON THE ROLE OF SEX STEROIDS IN THE AETIOLOGY OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC NEURO-INFLAMMATORY DISORDER THE DEFINING FEATURE OF WHICH IS THE GROWTH OF TISSUE (LESIONS) THAT RESEMBLES THE ENDOMETRIUM OUTSIDE THE UTERUS. ESTIMATES OF PREVALENCE QUOTE RATES OF ~10% OF WOMEN OF REPRODUCTIVE AGE, EQUATING TO AT LEAST 190 MILLION WOMEN WORLD-WIDE. GENETIC, HORMONAL AND IMMUNOLOGICAL FACTORS HAVE ALL BEEN PROPOSED AS CONTRIBUTING TO RISK FACTORS ASSOCIATED WITH THE DEVELOPMENT OF LESIONS. TWIN STUDIES REPORT THE HERITABLE COMPONENT OF ENDOMETRIOSIS AS ~50%. GENOME-WIDE ASSOCIATION STUDIES (GWAS) HAVE IDENTIFIED SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) THAT APPEAR OVER-REPRESENTED IN PATIENTS WITH ENDOMETRIOSIS, PARTICULARLY THOSE WITH MORE EXTENSIVE DISEASE (STAGE III/IV). IN DIFFERENT SAMPLE POPULATIONS, THERE HAS BEEN REPLICATION OF SNPS NEAR GENES INVOLVED IN OESTROGEN AND OTHER STEROID REGULATED PATHWAYS INCLUDING ESR1 (OESTROGEN RECEPTOR ALPHA), GREB1, HOXA10, WNT4 AND MAPK KINASE SIGNALLING. COMPARISONS WITH GWAS CONDUCTED ON OTHER PATIENT COHORTS HAVE FOUND LINKS WITH REPRODUCTIVE TRAITS (AGE AT MENARCHE) AND DISORDERS (FIBROIDS, ENDOMETRIAL AND OVARIAN CANCER) AND COMMON CO-MORBIDITIES (MIGRAINE, DEPRESSION, ASTHMA). IN SUMMARY, GENETIC ANALYSES HAVE PROVIDED NEW INSIGHTS INTO THE HORMONE-REGULATED PATHWAYS THAT MAY CONTRIBUTE TO INCREASED RISK OF DEVELOPING ENDOMETRIOSIS SOME OF WHICH MAY ACT IN EARLY LIFE. NEW STUDIES ARE NEEDED TO CLARIFY THE RELATIONSHIP BETWEEN THE MANY SNPS IDENTIFIED, THE GENES THAT THEY REGULATE AND THEIR CONTRIBUTION(S) TO DEVELOPMENT OF DIFFERENT FORMS OF ENDOMETRIOSIS. WE HOPE THAT MORE ADVANCED METHODS ALLOWING INTEGRATION BETWEEN GWAS, EPIGENETIC AND TISSUE EXPRESSION DATA WILL IMPROVE RISK ANALYSIS AND REDUCE DIAGNOSITIC DELAY. LAY SUMMARY: ENDOMETRIOSIS IS A DEBILITATING REPRODUCTIVE DISORDER AFFECTING ~10% OF REPRODUCTIVE-AGE WOMEN, AND THOSE ASSIGNED FEMALE AT BIRTH, WHICH CAUSES A RANGE OF SYMPTOMS INCLUDING CHRONIC PAIN AND INFERTILITY. THE REASON WHY SOME, BUT NOT ALL THESE INDIVIDUALS, DEVELOP THE LESIONS THAT CHARACTERISE THE DISEASE ARE POORLY UNDERSTOOD, BUT RECENTLY ATTENTION HAS FOCUSED ON GENETIC RISK FACTORS TO EXPLAIN WHY THE INCIDENCE IS HIGHER IN SOME FAMILIES. STUDIES ON LARGE COHORTS OF PATIENTS WITH COMPARISON OF THEIR DNA TO WOMEN WITHOUT ENDOMETRIOSIS OR WITH OTHER DISORDERS HAVE DOCUMENTED CHANGES IN GENES ASSOCIATED WITH STEROID HORMONE PRODUCTION OR ACTION. THE RESULTS PROVIDE FURTHER EVIDENCE THAT ENDOMETRIOSIS SHARES GENETIC RISK FACTORS WITH OTHER DISORDERS OF THE REPRODUCTIVE SYSTEM AND A PLATFORM FOR NEW IDEAS RELATED TO RISK, BIOMARKERS AND THERAPIES. 2022 2 605 55 BEYOND ENDOMETRIOSIS GENOME-WIDE ASSOCIATION STUDY: FROM GENOMICS TO PHENOMICS TO THE PATIENT. ENDOMETRIOSIS IS A HERITABLE, COMPLEX CHRONIC INFLAMMATORY DISEASE, FOR WHICH MUCH OF THE CAUSAL PATHOGENIC MECHANISM REMAINS UNKNOWN. GENOME-WIDE ASSOCIATION STUDIES (GWAS) TO DATE HAVE IDENTIFIED 12 SINGLE NUCLEOTIDE POLYMORPHISMS AT 10 INDEPENDENT GENETIC LOCI ASSOCIATED WITH ENDOMETRIOSIS. MOST OF THESE WERE MORE STRONGLY ASSOCIATED WITH REVISED AMERICAN FERTILITY SOCIETY STAGE III/IV, RATHER THAN STAGE I/II. THE LOCI ARE ALMOST ALL LOCATED IN INTERGENIC REGIONS THAT ARE KNOWN TO PLAY A ROLE IN THE REGULATION OF EXPRESSION OF TARGET GENES YET TO BE IDENTIFIED. TO IDENTIFY THE TARGET GENES AND PATHWAYS PERTURBED BY THE IMPLICATED VARIANTS, STUDIES ARE REQUIRED INVOLVING FUNCTIONAL GENOMIC ANNOTATION OF THE SURROUNDING CHROMOSOMAL REGIONS, IN TERMS OF TRANSCRIPTION FACTOR BINDING, EPIGENETIC MODIFICATION (E.G., DNA METHYLATION AND HISTONE MODIFICATION) SITES, AS WELL AS THEIR CORRELATION WITH RNA TRANSCRIPTION. THESE STUDIES NEED TO BE CONDUCTED IN TISSUE TYPES RELEVANT TO ENDOMETRIOSIS-IN PARTICULAR, ENDOMETRIUM. IN ADDITION, TO ALLOW BIOLOGICALLY AND CLINICALLY RELEVANT INTERPRETATION OF MOLECULAR PROFILING DATA, THEY NEED TO BE COMBINED AND CORRELATED WITH DETAILED, SYSTEMATICALLY COLLECTED PHENOTYPIC INFORMATION (SURGICAL AND CLINICAL). THE WERF ENDOMETRIOSIS PHENOME AND BIOBANKING HARMONISATION PROJECT IS A GLOBAL STANDARDIZATION INITIATIVE THAT HAS PRODUCED CONSENSUS DATA AND SAMPLE COLLECTION PROTOCOLS FOR ENDOMETRIOSIS RESEARCH. THESE NOW PAVE THE WAY FOR COLLABORATIVE STUDIES INTEGRATING PHENOMIC WITH GENOMIC DATA, TO IDENTIFY INFORMATIVE SUBTYPES OF ENDOMETRIOSIS THAT WILL ENHANCE UNDERSTANDING OF THE PATHOGENIC MECHANISMS OF THE DISEASE AND DISCOVERY OF NOVEL, TARGETED TREATMENTS. 2016 3 5378 33 RECENT INSIGHTS ON THE GENETICS AND EPIGENETICS OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A GYNECOLOGIC DISEASE AFFECTING UP TO 10% OF THE WOMEN AND A MAJOR CAUSE OF PAIN AND INFERTILITY. IT IS CHARACTERIZED BY THE IMPLANTATION OF FUNCTIONAL ENDOMETRIAL TISSUE AT ECTOPIC POSITIONS GENERALLY WITHIN THE PERITONEUM. THIS COMPLEX DISEASE HAS AN IMPORTANT GENETIC COMPONENT WITH A HERITABILITY ESTIMATED AT AROUND 50%. THIS REVIEW AIMS AT PROVIDING RECENT INSIGHTS INTO THE GENETIC BASES OF ENDOMETRIOSIS, AND PRESENTS A DETAILED OVERVIEW OF EVIDENCE OF EPIGENETIC ALTERATIONS SPECIFIC TO THIS DISEASE. IN THE FUTURE, THESE ALTERATIONS MAY CONSTITUTE THERAPEUTIC TARGETS FOR PHARMACOLOGICAL COMPOUNDS ABLE TO MODIFY THE EPIGENETIC CODE. 2017 4 3005 47 GENETIC, EPIGENETIC, AND STEROIDOGENIC MODULATION MECHANISMS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC GYNECOLOGICAL DISEASE, AFFECTING UP TO 10% OF REPRODUCTIVE-AGE WOMEN. THE EXACT CAUSE OF THE DISEASE IS UNKNOWN; HOWEVER, IT IS A HERITABLE CONDITION AFFECTED BY MULTIPLE GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. PREVIOUS STUDIES REPORTED VARIATIONS IN THE EPIGENETIC PATTERNS OF NUMEROUS GENES KNOWN TO BE INVOLVED IN THE ABERRANT MODULATION OF CELL CYCLE STEROIDOGENESIS, ABNORMAL HORMONAL, IMMUNE AND INFLAMMATORY STATUS IN ENDOMETRIOSIS, APOPTOSIS, ADHESION, ANGIOGENESIS, PROLIFERATION, IMMUNE AND INFLAMMATORY PROCESSES, RESPONSE TO HYPOXIA, STEROIDOGENIC PATHWAY AND HORMONE SIGNALING ARE INVOLVED IN THE PATHOGENESIS OF ENDOMETRIOSIS. ACCUMULATING EVIDENCE SUGGEST THAT VARIOUS EPIGENETIC ABERRATIONS MAY CONTRIBUTE TO THE PATHOGENESIS OF ENDOMETRIOSIS. AMONG THEM, DNA METHYLTRANSFERASES, HISTONE DEACETYLATORS, AND NON-CODING MICRORNAS DEMONSTRATE DIFFERENTIAL EXPRESSION WITHIN ENDOMETRIOTIC LESIONS AND IN THE ENDOMETRIUM OF PATIENTS WITH ENDOMETRIOSIS. IT HAS BEEN INDICATED THAT THE IDENTIFICATION OF EPIGENETIC DIFFERENCES WITHIN THE DNA OR HISTONE PROTEINS MAY CONTRIBUTE TO THE DISCOVERY OF A USEFUL PROGNOSTIC BIOMARKER, WHICH COULD AID IN THE FUTURE EARLIER DETECTION, TIMELY DIAGNOSIS, AND INITIATION OF A NEW APPROACH TO THE TREATMENT OF ENDOMETRIOSIS, AS WELL AS INFORM US ABOUT THE EFFECTIVENESS OF TREATMENT AND THE STAGE OF THE DISEASE. AS THE ETIOLOGY OF ENDOMETRIOSIS IS HIGHLY COMPLEX AND STILL FAR FROM BEING FULLY ELUCIDATED, THE PRESENTED REVIEW FOCUSES ON DIFFERENT APPROACHES TO IDENTIFY THE GENETIC AND EPIGENETIC LINKS OF ENDOMETRIOSIS AND ITS PATHOGENESIS. 2020 5 6116 40 THE EPIGENETIC CORRELATION AMONG OVARIAN CANCER, ENDOMETRIOSIS AND PCOS: A REVIEW. OVARIAN CANCER IS A FREQUENT MALIGNANCY THAT AFFECTS A LARGE PERCENTAGE OF WOMEN. ENDOMETRIOSIS IS A CHRONIC CONDITION, WHERE THERE IS A PRODUCTION OF BENIGN LESIONS WERE OBSERVED IN THE UTERINE ENVIRONMENT. PCOS IS A METABOLIC DISORDER CHARACTERIZED BY THE PRESENCE OF NUMEROUS CYSTS IN THE OVARIES. THE RELATION BETWEEN OVARIAN MALIGNANCIES AND PCOS, BY AN INCREASED RATIO OF OVARIAN STROMAL TISSUES IN PCOS PATIENTS. THE DIRECT CORRELATION IS NOT YET CONFIRMED AMONG THE THREE DISORDERS, BUT IT IS OFTEN NOTED THAT THEY SHARE RISK FACTORS, SUCH AS OBESITY, HORMONAL IMBALANCES. EPIGENETIC FACTORS HAVE SHOWN TO BE AN IMPORTANT REASON FOR CANCER PROGRESSION. OUR FINDINGS AT THE EPIGENETIC LEVEL INCLUDES A COMPARATIVE ANALYSIS, POINT MUTATIONS IN GENES, OVERACTIVATION OF SIGNALING PATHWAYS. THIS REVIEW PAPER, HIGHLIGHT THE POSSIBLE CORRELATION BETWEEN THE THREE DISORDERS IN TERMS OF GENETIC AND EPIGENETIC FACTORS AND HOW IT COULD TOGETHER TRIGGER THE CANCER PROGRESSION AND METASTASIS. 2022 6 5892 65 SYSTEMS GENETICS VIEW OF ENDOMETRIOSIS: A COMMON COMPLEX DISORDER. ENDOMETRIOSIS IS A CONDITION IN WHICH CELLS DERIVED FROM THE ENDOMETRIUM GROW OUTSIDE THE UTERUS, E.G. IN THE PERITONEUM (EXTERNAL GENITAL ENDOMETRIOSIS). AS THESE CELLS ARE UNDER THE INFLUENCE OF FEMALE HORMONES, MAJOR SYMPTOMS OF ENDOMETRIOSIS ARE PAIN, ESPECIALLY DURING THE CYCLE, AND INFERTILITY. NUMEROUS HYPOTHESES FOR THE FORMATION OF ENDOMETRIOSIS CAN BE FOUND IN THE LITERATURE, BUT THERE IS GROWING EVIDENCE OF SERIOUS GENETIC CONTRIBUTIONS TO ENDOMETRIOSIS SUSCEPTIBILITY. THE INVOLVEMENT OF GENES, STEROID HORMONE METABOLISM, IMMUNOLOGICAL REACTIONS, RECEPTOR FORMATION, INFLAMMATION, PROLIFERATION, APOPTOSIS, INTERCELLULAR ADHESION, CELL INVASION AND ANGIOGENESIS AS WELL AS GENES REGULATING THE ACTIVITY OF AFOREMENTIONED ENZYMES HAVE BEEN SUGGESTED. SOME MORE RECENTLY SUGGESTED CANDIDATE GENES PICKED UP IN GENOME-WIDE ASSOCIATION STUDIES ARE INVOLVED IN ONCOGENESIS, METAPLASIA OF ENDOMETRIUM CELLS AND PATHWAYS OF EMBRYONIC DEVELOPMENT OF THE FEMALE REPRODUCTIVE SYSTEM. HOWEVER, GENE MUTATIONS PROVEN TO BE CAUSATIVE FOR ENDOMETRIOSIS HAVE NOT BEEN IDENTIFIED SO FAR, EVEN THOUGH THE ABNORMAL EXPRESSION OF CANDIDATE GENES FOR ENDOMETRIOSIS COULD BE PROVOKED BY DIFFERENT EPIGENETIC MODIFICATIONS INCLUDING DNA METHYLATION, HETEROCHROMATIZATION OR INTRODUCTION OF REGULATORY MIRNA. WE HYPOTHESIZE THAT ENDOMETRIOSIS IS INDUCED BY A COMBINATION OF ABNORMAL GENETIC AND/OR EPIGENETIC MUTATIONS: THE LATTER PAVE THE WAY FOR PATHOLOGICAL CHANGES WHICH BECOME IRREVERSIBLE, AND ACCORDING TO THE "EPIGENETIC LANDSCAPE" THEORY, THIS PROCEEDS TO THE TYPICAL CLINICAL MANIFESTATIONS. TWO STAGES IN THE ENDOMETRIOSIS PATHWAY ARE SUGGESTED: (1) INDUCTION OF PRIMARY ENDOMETRIAL CELLS TOWARD ENDOMETRIOSIS, AND (2) IMPLANTATION AND PROGRESSION OF THESE CELLS INTO ENDOMETRIOSIS LESIONS. THE MODEL FAVORS ENDOMETRIOSIS AS AN OUTGROWTH OF PRIMARY CELLS DIFFERENT IN THEIR ORIGIN, CANALIZATION OF PATHOLOGICAL PROCESSES, MANIFESTATION DIVERSITY PROVOKED BY UNIQUE GENETIC BACKGROUND AND EPIGENETIC INFLUENCES, WHICH RESULT IN MANY DIFFERENT CLINICAL FORMS OF THE DISEASE. 2015 7 6159 50 THE GENETICS AND EPIGENETICS OF FATIGUE. FATIGUE IS A COMMON SYMPTOM AND INCLUDES BOTH PHYSICAL AND MENTAL COMPONENTS. IT CAN BE ASSOCIATED WITH A VARIETY OF DIFFERENT SYNDROMES AND DISEASES, BUT IN MANY CASES IS NOT ASSOCIATED WITH OTHER COMORBID CONDITIONS. MOST HUMANS HAVE EXPERIENCED ACUTE FATIGUE IN RELATION TO DIFFERENT STRESSORS. ACUTE FATIGUE TYPICALLY DECREASES AS THE EFFECT OF THE TRIGGERING FACTOR IS REDUCED AND A NORMAL HOMEOSTATIC BALANCE IS RESTORED. FATIGUE THAT PERSISTS FOR 6 MONTHS OR MORE IS TERMED CHRONIC FATIGUE. CHRONIC FATIGUE (CF) IN COMBINATION WITH A MINIMUM OF 4 OF 8 SYMPTOMS AND THE ABSENCE OF DISEASES THAT COULD EXPLAIN THESE SYMPTOMS, CONSTITUTE THE CASE DEFINITION FOR CHRONIC FATIGUE SYNDROME. IN SPITE OF ITS PREVALENCE, THE BIOLOGY OF FATIGUE IS RELATIVELY POORLY UNDERSTOOD AND BIOLOGICAL MARKERS HAVE NOT YET BEEN IDENTIFIED. THIS LITERATURE SEARCH WAS PERFORMED IN PUBMED TO IDENTIFY RESEARCH ON THE GENETICS AND EPIGENETICS OF FATIGUE. PUBLICATIONS WERE INCLUDED IF FATIGUE WAS A MAJOR TOPIC AND THE TOPIC WAS COMBINED WITH GENETIC AND/OR EPIGENETIC MEASUREMENTS IN ADULT HUMANS. A TOTAL OF 40 PUBLICATIONS WERE IDENTIFIED. ALTHOUGH ALTERED FUNCTIONING IN THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS, THE SEROTONERGIC SYSTEM, AND ASSOCIATIONS WITH INFECTIOUS AGENTS HAVE BEEN IDENTIFIED, THE SEARCH FOR GENETIC OR EPIGENETIC MARKERS OF FATIGUE, EITHER IN THE CONTEXT OF CF OR CHRONIC FATIGUE SYNDROME (CFS) HAS BEEN RELATIVELY UNPRODUCTIVE OR, IN THE CASE OF EPIGENETICS, NONEXISTENT. ALTHOUGH SEVERAL STUDIES, BOTH HYPOTHESIS-TESTING AND HYPOTHESIS-GENERATING, HAVE BEEN PERFORMED TO SEARCH FOR BIOMARKERS, THEY HAVE MOSTLY BEEN UNDERPOWERED, RESTRICTED BY THE HETEROGENEITY OF THE PHENOTYPE, OR LIMITED BY AN UNSYSTEMATIC STUDY DESIGN. TO BE ABLE TO CONFIRM THE HYPOTHESIS THAT RISK FOR, OR LEVELS OF, FATIGUE ARE INFLUENCED BY THE GENETIC OR EPIGENETIC BACKGROUND OF AN INDIVIDUAL, STUDIES NEED TO BE BASED ON LARGER SAMPLE SIZES WITH A MORE CLEARLY DEFINED PHENOTYPE. STUDIES NEED TO FOCUS NOT ONLY ON THE INFLUENCE OF A SINGLE ASPECT SUCH AS SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) OR DIFFERENTIAL GENE EXPRESSION ON DISEASE RISK OR STATE, BUT ALSO ON THE SYSTEMS BIOLOGY BEHIND THE DISEASE IN COMBINATION WITH INFORMATION ON ENVIRONMENTAL INFLUENCES AND VALIDATION OF FINDINGS IN FUNCTIONAL STUDIES. 2010 8 5643 46 SEX AND AUTOIMMUNITY: PROPOSED MECHANISMS OF DISEASE ONSET AND SEVERITY. CHRONIC AUTOIMMUNE DISEASES AFFECT 5-10% OF THE POPULATION WORLDWIDE AND ARE LARGELY PREDOMINANT IN WOMEN. SEX HORMONE CHANGES HAVE BEEN WIDELY INVESTIGATED BASED ON CHANGES IN THE CLINICAL PHENOTYPES OBSERVED DURING PREGNANCY AND MENOPAUSE. IT IS KNOWN THAT FEMALES WITH AUTOIMMUNE DISEASES MANIFEST A HIGHER RATE OF CIRCULATING LEUKOCYTES WITH A SINGLE X CHROMOSOME, AND THERE HAVE BEEN SEVERAL REPORTS ON THE ROLE OF X CHROMOSOME GENE DOSAGE THROUGH INACTIVATION OR DUPLICATION IN AUTOIMMUNITY. HOWEVER, IT IS ALSO IMPORTANT NOT TO OVERLOOK MEN WITH AUTOIMMUNE DISEASES, WHO MIGHT MANIFEST A MORE FREQUENT LOSS OF THE Y CHROMOSOME IN CIRCULATING LEUKOCYTES. AREAS COVERED: IN THE PRESENT REVIEW, WE WILL DISCUSS THE CURRENT EVIDENCE SUPPORTING THE MECHANISMS OF FEMALE PREDOMINANCE IN RHEUMATIC DISEASES, BY DISCUSSING THE ROLE OF REPRODUCTIVE HISTORY, SEX HORMONES AND ABNORMALITIES RELATED TO THEM, CLINICAL DIFFERENCES BETWEEN MALE AND FEMALE PATIENTS, AND EPIGENETIC CHANGES THAT HAVE BEEN EVALUATED THROUGH TWIN STUDIES ON GENETIC AND ENVIRONMENTAL CHANGES IN RHEUMATIC PATIENTS. EXPERT OPINION: THE INFLUENCE OF SEX HORMONES AND CHROMOSOMES ON THE FUNCTION OF THE INNATE AND ADAPTIVE IMMUNE SYSTEMS NEEDS TO BE CLARIFIED, TO BETTER UNDERSTAND THE RISK OF AUTOIMMUNE DISEASES, EARLY DIAGNOSTIC TOOLS, AND THERAPEUTIC RESPONSE. 2019 9 1028 52 CIRCULATING MIRNAS RELATED TO EPITHELIAL-MESENCHYMAL TRANSITIONS (EMT) AS THE NEW MOLECULAR MARKERS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC GYNECOLOGICAL DISEASE DEFINED BY THE PRESENCE OF ENDOMETRIAL-LIKE TISSUE FOUND OUTSIDE THE UTERUS, MOST COMMONLY IN THE PERITONEAL CAVITY. ENDOMETRIOSIS LESIONS ARE HETEROGENOUS BUT USUALLY CONTAIN ENDOMETRIAL STROMAL CELLS AND EPITHELIAL GLANDS, IMMUNE CELL INFILTRATES AND ARE VASCULARIZED AND INNERVATED BY NERVES. THE COMPLEX ETIOPATHOGENESIS AND HETEROGENITY OF THE CLINICAL SYMPTOMS, AS WELL AS THE LACK OF A SPECIFIC NON-INVASIVE DIAGNOSTIC BIOMARKERS, UNDERLINE THE NEED FOR MORE ADVANCED DIAGNOSTIC TOOLS. UNFORTUNATELY, THE CONTRIBUTION OF ENVIRONMENTAL, HORMONAL AND IMMUNOLOGICAL FACTORS IN THE DISEASE ETIOLOGY IS INSUFFICIENT, AND THE CONTRIBUTION OF GENETIC/EPIGENETIC FACTORS IS STILL FRAGMENTARY. THEREFORE, THERE IS A NEED FOR MORE FOCUSED STUDY ON THE MOLECULAR MECHANISMS OF ENDOMETRIOSIS AND NON-INVASIVE DIAGNOSTIC MONITORING SYSTEMS. MICRORNAS (MIRNAS) DEMONSTRATE HIGH STABILITY AND TISSUE SPECIFICITY AND PLAY A SIGNIFICANT ROLE IN MODULATING A RANGE OF MOLECULAR PATHWAYS, AND HENCE MAY BE SUITABLE DIAGNOSTIC BIOMARKERS FOR THE ORIGIN AND DEVELOPMENT OF ENDOMETRIOSIS. OF THESE, THE MOST FREQUENTLY STUDIED ARE THOSE RELATED TO ENDOMETRIOSIS, INCLUDING THOSE INVOLVED IN EPITHELIAL-MESENCHYMAL TRANSITION (EMT), WHOSE EXPRESSION IS ALTERED IN PLASMA OR ENDOMETRIOTIC LESION BIOPSIES; HOWEVER, THE RESULTS ARE AMBIGUOUS. SPECIFIC MIRNAS EXPRESSED IN ENDOMETRIOSIS MAY SERVE AS DIAGNOSTICS MARKERS WITH PROGNOSTIC VALUE, AND THEY HAVE BEEN PROPOSED AS MOLECULAR TARGETS FOR TREATMENT. THE AIM OF THIS REVIEW IS TO PRESENT SELECTED MIRNAS ASSOCIATED WITH EMT KNOWN TO HAVE EXPERIMENTALLY CONFIRMED SIGNIFICANCE, AND DISCUSS THEIR UTILITY AS BIOMARKERS IN ENDOMETRIOSIS. 2021 10 4957 46 PATHOGENESIS OF ENDOMETRIOSIS: THE GENETIC/EPIGENETIC THEORY. OBJECTIVE: TO STUDY THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS. DESIGN: OVERVIEW OF OBSERVATIONS ON ENDOMETRIOSIS. SETTING: NOT APPLICABLE. PATIENT(S): NONE. INTERVENTIONS(S): NONE. MAIN OUTCOME MEASURE(S): THE HYPOTHESIS IS COMPATIBLE WITH ALL OBSERVATIONS. RESULT(S): ENDOMETRIOSIS, ENDOMETRIUM-LIKE TISSUE OUTSIDE THE UTERUS, HAS A VARIABLE MACROSCOPIC APPEARANCE AND A POORLY UNDERSTOOD NATURAL HISTORY. IT IS A HEREDITARY AND HETEROGENEOUS DISEASE WITH MANY BIOCHEMICAL CHANGES IN THE LESIONS, WHICH ARE CLONAL IN ORIGIN. IT IS ASSOCIATED WITH PAIN, INFERTILITY, ADENOMYOSIS, AND CHANGES IN THE JUNCTIONAL ZONE, PLACENTATION, IMMUNOLOGY, PLASMA, PERITONEAL FLUID, AND CHRONIC INFLAMMATION OF THE PERITONEAL CAVITY. THE SAMPSON HYPOTHESIS OF IMPLANTED ENDOMETRIAL CELLS FOLLOWING RETROGRADE MENSTRUATION, ANGIOGENIC SPREAD, LYMPHOGENIC SPREAD, OR THE METAPLASIA THEORY CANNOT EXPLAIN ALL OBSERVATIONS IF METAPLASIA IS DEFINED AS CELLS WITH REVERSIBLE CHANGES AND AN ABNORMAL BEHAVIOR/MORPHOLOGY DUE TO THE ABNORMAL ENVIRONMENT. WE PROPOSE A POLYGENETIC/POLYEPIGENETIC MECHANISM. THE SET OF GENETIC AND EPIGENETIC INCIDENTS TRANSMITTED AT BIRTH COULD EXPLAIN THE HEREDITARY ASPECTS, THE PREDISPOSITION, AND THE ENDOMETRIOSIS-ASSOCIATED CHANGES IN THE ENDOMETRIUM, IMMUNOLOGY, AND PLACENTATION. TO DEVELOP TYPICAL, CYSTIC OVARIAN OR DEEP ENDOMETRIOSIS LESIONS, A VARIABLE SERIES OF ADDITIONAL TRANSMISSIBLE GENETIC AND EPIGENETIC INCIDENTS ARE REQUIRED TO OCCUR IN A CELL WHICH MAY VARY FROM ENDOMETRIAL TO STEM CELLS. SUBTLE LESIONS ARE VIEWED AS ENDOMETRIUM IN A DIFFERENT ENVIRONMENT UNTIL ADDITIONAL INCIDENTS OCCUR. TYPICAL CYSTIC OVARIAN OR DEEP ENDOMETRIOSIS LESIONS ARE HETEROGENEOUS AND REPRESENT THREE DIFFERENT DISEASES. CONCLUSION(S): THE GENETIC EPIGENETIC THEORY IS COMPATIBLE WITH ALL OBSERVATIONS ON ENDOMETRIOSIS. IMPLICATIONS FOR TREATMENT AND PREVENTION ARE DISCUSSED. 2019 11 506 45 ASSOCIATION OF ENDOMETRIOSIS WITH CARDIOVASCULAR DISEASE: GENETIC ASPECTS (REVIEW). CARDIOVASCULAR DISEASE (CVD) COMPRISES A BROAD SPECTRUM OF PATHOLOGICAL CONDITIONS THAT AFFECT THE HEART OR BLOOD VESSELS, INCLUDING SEQUELAE THAT ARISE FROM DAMAGED VASCULATURE IN OTHER ORGANS OF THE BODY, SUCH AS THE BRAIN, KIDNEYS OR EYES. ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY DISEASE OF THE ARTERIAL INTIMA AND IS THE PRIMARY CAUSE OF CORONARY ARTERY DISEASE, PERIPHERAL VASCULAR DISEASE, HEART ATTACK, STROKE AND RENAL PATHOLOGY. IT REPRESENTS A LEADING CAUSE OF MORTALITY WORLDWIDE AND THE LOSS OF HUMAN PRODUCTIVITY THAT IS MARKED BY AN ALTERED IMMUNE RESPONSE. ENDOMETRIOSIS IS A HERITABLE, HETEROGENEOUS, COMMON GYNECOLOGICAL CONDITION INFLUENCED BY MULTIPLE GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS, AFFECTING UP TO 10% OF THE FEMALE POPULATION OF CHILDBEARING AGE, CAUSING PAIN AND INFERTILITY; IT IS CHARACTERIZED BY THE ECTOPIC GROWTH OF ENDOMETRIAL TISSUE OUTSIDE THE UTERINE CAVITY. OF NOTE, EPIDEMIOLOGICAL DATA OBTAINED THUS FAR HAVE SUGGESTED A LINK BETWEEN ENDOMETRIOSIS AND THE RISK OF DEVELOPING CVD. THE SIMILARITIES OBSERVED IN SPECIFIC MOLECULAR AND CELLULAR PATHWAYS OF ENDOMETRIOSIS AND CVD MAY BE PARTIALLY EXPLAINED BY A SHARED GENETIC BACKGROUND. THE PRESENT REVIEW PRESENTS AND DISCUSSES THE SHARED GENETIC FACTORS WHICH HAVE BEEN REPORTED TO BE ASSOCIATED WITH THE DEVELOPMENT OF BOTH DISORDERS. 2023 12 3003 63 GENETIC, EPIGENETIC AND STEM CELL ALTERATIONS IN ENDOMETRIOSIS: NEW INSIGHTS AND POTENTIAL THERAPEUTIC PERSPECTIVES. HUMAN ENDOMETRIUM IS A HIGHLY DYNAMIC TISSUE, UNDERGOING PERIODIC GROWTH AND REGRESSION AT EACH MENSTRUAL CYCLE. ENDOMETRIOSIS IS A FREQUENT CHRONIC PATHOLOGICAL STATUS CHARACTERIZED BY ENDOMETRIAL TISSUE WITH AN ECTOPIC LOCALIZATION, CAUSING PELVIC PAIN AND INFERTILITY AND A VARIABLE CLINICAL PRESENTATION. IN ADDITION, THERE IS WELL-ESTABLISHED EVIDENCE THAT, ALTHOUGH ENDOMETRIOSIS IS CONSIDERED BENIGN, IT IS ASSOCIATED WITH AN INCREASED RISK OF MALIGNANT TRANSFORMATION IN APPROXIMATELY 1.0% OF AFFECTED WOMEN, WITH THE INVOLVEMENT OF MULTIPLE PATHWAYS OF DEVELOPMENT. INCREASING EVIDENCE SUPPORTS A KEY CONTRIBUTION OF DIFFERENT STEM/PROGENITOR CELL POPULATIONS NOT ONLY IN THE CYCLIC REGENERATION OF EUTOPIC ENDOMETRIUM, BUT ALSO IN THE PATHOGENESIS OF AT LEAST SOME TYPES OF ENDOMETRIOSIS. EVIDENCE HAS ARISEN FROM EXPERIMENTS IN ANIMAL MODELS OF DISEASE THROUGH DIFFERENT KINDS OF ASSAYS (INCLUDING CLONOGENICITY, THE LABEL-RETAINING CELL APPROACH, THE ANALYSIS OF UNDIFFERENTIATION MARKERS), AS WELL AS FROM DESCRIPTIVE STUDIES ON ECTOPIC AND EUTOPIC TISSUE SAMPLES HARVESTED FROM AFFECTED WOMEN. CHANGES IN STEM CELL POPULATIONS IN ENDOMETRIOTIC LESIONS ARE ASSOCIATED WITH GENETIC AND EPIGENETIC ALTERATIONS, INCLUDING IMBALANCE OF MIRNA EXPRESSION, HISTONE AND DNA MODIFICATIONS AND CHROMOSOMAL ABERRATIONS. THE PRESENT SHORT REVIEW MAINLY SUMMARIZES THE LATEST OBSERVATIONS CONTRIBUTING TO THE CURRENT KNOWLEDGE REGARDING THE PRESENCE AND THE POTENTIAL CONTRIBUTION OF STEM/PROGENITOR CELLS IN EUTOPIC ENDOMETRIUM AND THE AETIOLOGY OF ENDOMETRIOSIS, TOGETHER WITH A REPORT OF THE MOST RECENTLY IDENTIFIED GENETIC AND EPIGENETIC ALTERATIONS IN ENDOMETRIOSIS. WE ALSO DESCRIBE THE POTENTIAL ADVANTAGES OF SINGLE CELL MOLECULAR PROFILING IN ENDOMETRIUM AND IN ENDOMETRIOTIC LESIONS. ALL THESE DATA CAN HAVE CLINICAL IMPLICATIONS AND PROVIDE A BASIS FOR NEW POTENTIAL THERAPEUTIC APPLICATIONS. 2014 13 2651 50 EPIGENOMICS AND TRANSCRIPTOMICS IN THE PREDICTION AND DIAGNOSIS OF CHILDHOOD ASTHMA: ARE WE THERE YET? ASTHMA IS THE MOST COMMON NON-COMMUNICABLE CHRONIC DISEASE OF CHILDHOOD. DESPITE ITS HIGH PREVALENCE, TO DATE WE LACK METHODS THAT ARE BOTH EFFICIENT AND ACCURATE IN DIAGNOSING ASTHMA. MOST TRADITIONAL APPROACHES HAVE BEEN BASED ON GARNERING CLINICAL EVIDENCE, SUCH AS RISK FACTORS AND EXPOSURES. GIVEN THE HIGH HERITABILITY OF ASTHMA, MORE RECENT APPROACHES HAVE LOOKED AT GENETIC POLYMORPHISMS AS POTENTIAL "RISK FACTORS." HOWEVER, GENETIC VARIANTS EXPLAIN ONLY A SMALL PROPORTION OF ASTHMA RISK, AND HAVE BEEN LESS THAN OPTIMAL AT PREDICTING RISK FOR INDIVIDUAL SUBJECTS. EPIGENOMIC STUDIES OFFER SIGNIFICANT ADVANTAGES OVER PREVIOUS APPROACHES. EPIGENETIC REGULATION IS HIGHLY TISSUE-SPECIFIC, AND CAN INDUCE BOTH SHORT- AND LONG-TERM CHANGES IN GENE EXPRESSION. SUCH CHANGES CAN START IN UTERO, CAN VARY THROUGHOUT THE LIFE SPAN, AND IN SOME INSTANCES CAN BE PASSED ON FROM ONE GENERATION TO ANOTHER. MOST IMPORTANTLY, THE EPIGENOME CAN BE MODIFIED BY ENVIRONMENTAL FACTORS AND EXPOSURES, AND THUS EPIGENETIC AND TRANSCRIPTOMIC PROFILING MAY YIELD THE MOST ACCURATE RISK ESTIMATES FOR A GIVEN PATIENT BY INCORPORATING ENVIRONMENTAL (AND TREATMENT) EFFECTS THROUGHOUT THE LIFESPAN. HERE WE WILL REVIEW THE MOST RECENT ADVANCES IN THE USE OF EPIGENETIC AND TRANSCRIPTOMIC ANALYSIS FOR THE EARLY DIAGNOSIS OF ASTHMA AND ATOPY, AS WELL AS CHALLENGES AND FUTURE DIRECTIONS IN THE FIELD AS IT MOVES FORWARD. WE WILL PARTICULARLY FOCUS ON DNA METHYLATION, THE MOST STUDIED MECHANISM OF EPIGENETIC REGULATION. 2019 14 1202 48 COULD DNA HYDROXYMETHYLATION BE CRUCIAL IN INFLUENCING STEROID HORMONE SIGNALING IN ENDOMETRIAL BIOLOGY AND ENDOMETRIOSIS? ENDOMETRIOSIS AFFECTS 10% OF REPRODUCTIVE-AGED WOMEN. IT IS CHARACTERIZED BY THE GROWTH OF THE ENDOMETRIUM, OUTSIDE THE UTERUS AND IS ASSOCIATED WITH INFERTILITY AND CHRONIC ABDOMINAL PAIN. LACK OF NONINVASIVE DIAGNOSTIC TOOLS AND EARLY SCREENING TESTS RESULTS IN DELAYED TREATMENT AND SUBSEQUENTLY INCREASED DISEASE SEVERITY. ENDOMETRIOSIS IS A DISEASE ASSOCIATED WITH A DEREGULATED HORMONAL RESPONSE, THEREFORE, UNDERSTANDING THE MOLECULAR MECHANISMS THAT GOVERN THIS HORMONAL INTERPLAY IS OF PARAMOUNT IMPORTANCE. DNA METHYLATION IS AN EPIGENETIC MARK THAT REGULATES GENE EXPRESSION AND IS OFTEN ASSOCIATED WITH GENES THAT CODE FOR STEROID RECEPTORS AND ENZYMES ASSOCIATED WITH ESTROGEN SYNTHESIS AND METABOLISM IN ENDOMETRIOSIS. DNA HYDROXYMETHYLATION, WHICH IS STRUCTURALLY SIMILAR TO METHYLATION BUT FUNCTIONALLY DIFFERENT, IS A BIOLOGICALLY CRITICAL MECHANISM THAT IS ALSO KNOWN TO REGULATE GENE EXPRESSION. TEN ELEVEN TRANSLOCATION (TET) PROTEINS MEDIATE HYDROXYMETHYLATION. HOWEVER, THE ROLE OF DNA HYDROXYMETHYLATION OR TETS IN THE ENDOMETRIUM REMAINS RELATIVELY UNEXPLORED. CURRENTLY, THE "GOLD STANDARD" TECHNIQUE USED TO STUDY METHYLATION PATTERNS IS BISULFITE GENOMIC SEQUENCING. THIS TECHNIQUE ALSO DETECTS HYDROXYMETHYLATION BUT FAILS TO DISTINGUISH BETWEEN THE TWO, THEREBY LIMITING OUR UNDERSTANDING OF THESE TWO PROCESSES. THE PRESENCE OF TETS IN THE MALE AND FEMALE REPRODUCTIVE TRACT AND ITS CONTRIBUTION TO ENDOMETRIAL CANCER MAKES IT AN IMPORTANT FACTOR TO STUDY IN ENDOMETRIOSIS. THIS REVIEW SUMMARIZES THE ROLE OF DNA METHYLATION IN ABERRANT STEROID HORMONE SIGNALING AND HYPOTHESIZES THAT HYDROXYMETHYLATION COULD BE A FACTOR INFLUENCING HORMONAL INSTABILITY SEEN IN ENDOMETRIOSIS. 2020 15 2107 45 EPIGENETIC FACTORS IN SCHIZOPHRENIA: MECHANISMS AND EXPERIMENTAL APPROACHES. SCHIZOPHRENIA IS A CHRONIC MENTAL DISORDER THAT IS STILL POORLY UNDERSTOOD DESPITE DECADES OF STUDY. MANY FACTORS HAVE BEEN FOUND TO CONTRIBUTE TO THE PATHOGENESIS, INCLUDING NEURODEVELOPMENTAL DISTURBANCE, GENETIC RISK, AND ENVIRONMENTAL INSULT, BUT NO SINGLE ROOT CAUSE HAS EMERGED. WHILE EVIDENCE FROM TWIN STUDIES SUGGESTS A STRONG HERITABLE COMPONENT, FEW INDIVIDUAL LOCI HAVE BEEN IDENTIFIED IN GENOMEWIDE SCREENS, SUGGESTING A ROLE FOR EPIGENETIC EFFECTS. RATHER, LARGE NUMBERS OF WEAKLY ACTING LOCI MAY CUMULATIVELY INCREASE DISEASE RISK, INCLUDING SEVERAL MAPPING TO EPIGENETIC PATHWAYS. IN THIS REVIEW, WE DISCUSS MECHANISMS OF EPIGENETIC REGULATION AND EVIDENCE FOR AN EPIGENETIC CONTRIBUTION TO DISEASE PHENOTYPE. WE FURTHER DESCRIBE THE RANGE OF EXPERIMENTAL TOOLS CURRENTLY AVAILABLE TO STUDY EPIGENETIC EFFECTS ASSOCIATED WITH THE DISEASE. 2019 16 1844 53 EFFECTS OF THE LIFESTYLE HABITS IN BREAST CANCER TRANSCRIPTIONAL REGULATION. THROUGH RESEARCH CARRIED OUT IN THE LAST 25 YEARS ABOUT THE BREAST CANCER ETIOLOGY, IT HAS BEEN POSSIBLE TO ESTIMATE THAT LESS THAN 10 % OF PATIENTS WHO ARE DIAGNOSED WITH THE CONDITION ARE CARRIERS OF SOME GERMLINE OR SOMATIC MUTATION. THE CLINICAL REPORTS OF BREAST CANCER PATIENTS WITH HEALTHY TWINS AND THE DEVELOPMENT OF DISEASE IN WOMEN WITHOUT HIGH PENETRANCE MUTATIONS DETECTED, WARN THE PARTICIPATION MORE FACTORS IN THE TRANSFORMATION PROCESS. THE HIGH INCIDENCE OF MAMMARY ADENOCARCINOMA IN THE MODERN WOMAN AND THE URGENT NEED FOR NEW METHODS OF PREVENTION AND EARLY DETECTION HAVE DEMANDED MORE INFORMATION ABOUT THE ROLE THAT ENVIRONMENT AND LIFESTYLE HAVE ON THE TRANSFORMATION OF MAMMARY GLAND EPITHELIAL CELLS. OBESITY, ALCOHOLISM AND SMOKING ARE FACTORS THAT HAVE SHOWN A CLOSE CORRELATION WITH THE RISK OF DEVELOPING BREAST CANCER. AND ALTHOUGH THESE CONDITIONS AFFECT DIFFERENT CELL REGULATION LEVELS, THE STUDY OF ITS EFFECTS IN THE MECHANISMS OF TRANSCRIPTIONAL AND EPIGENETIC REGULATION IS CONSIDERED CRITICAL FOR A BETTER UNDERSTANDING OF THE LOSS OF IDENTITY OF EPITHELIAL CELLS DURING CARCINOGENESIS OF THIS TISSUE. THE MAIN OBJECTIVE OF THIS REVIEW WAS TO ESTABLISH THE IMPORTANCE OF CHANGES OCCURRING TO TRANSCRIPTIONAL LEVEL IN THE MAMMARY GLAND AS A CONSEQUENCE OF ACUTE OR CHRONIC EXPOSURE TO HARMFUL PRODUCTS SUCH AS OBESITY-CAUSING FOODS, ETHANOL AND CIGARETTE SMOKE COMPONENTS. AT ANALYZE THE MAIN STUDIES RELATED TO TOPIC, IT HAS CONCLUDED THAT THE UNDERSTANDING OF EFFECTS CAUSED BY THE LIFESTYLE FACTORS IN PERFORMANCE OF THE TRANSCRIPTIONAL MECHANISMS THAT DETERMINE GENE EXPRESSION OF THE MAMMARY GLAND EPITHELIAL CELLS, MAY HELP EXPLAIN THE DEVELOPMENT OF THIS DISEASE IN WOMEN WITHOUT GENETIC PROPENSITY AND DIFFERENT PHENOTYPIC MANIFESTATIONS OF THIS CANCER TYPE. 2016 17 527 49 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 18 396 38 AN UPDATE ON EPIGENETICS AND CHILDHOOD RESPIRATORY DISEASES. EPIGENETIC MECHANISMS, DEFINED AS CHANGES IN PHENOTYPE OR GENE EXPRESSION CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE, HAVE BEEN PROPOSED TO CONSTITUTE A LINK BETWEEN GENETIC AND ENVIRONMENTAL FACTORS THAT AFFECT COMPLEX DISEASES. RECENT STUDIES SHOW THAT DNA METHYLATION, ONE OF THE KEY EPIGENETIC MECHANISMS, IS ALTERED IN CHILDREN EXPOSED TO AIR POLLUTANTS AND ENVIRONMENTAL TOBACCO SMOKE EARLY IN LIFE. SEVERAL CANDIDATE GENE STUDIES ON EPIGENETICS HAVE BEEN PUBLISHED TO DATE, BUT IT IS ONLY RECENTLY THAT GLOBAL METHYLATION ANALYSES HAVE BEEN PERFORMED FOR RESPIRATORY DISORDERS SUCH AS ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. HOWEVER, LARGE-SCALE STUDIES WITH ADEQUATE POWER ARE YET TO BE PRESENTED IN CHILDREN, AND IMPLICATIONS FOR CLINICAL USE REMAIN TO BE EVALUATED. IN THIS REVIEW, WE SUMMARIZE THE RECENT ADVANCES IN EPIGENETICS AND RESPIRATORY DISORDERS IN CHILDREN, WITH A MAIN FOCUS ON METHODOLOGICAL CHALLENGES AND ANALYSES RELATED TO PHENOTYPE AND EXPOSURE USING GLOBAL METHYLATION APPROACHES. 2014 19 738 34 CANCER SUSCEPTIBILITY: EPIGENETIC MANIFESTATION OF ENVIRONMENTAL EXPOSURES. CANCER IS A DISEASE THAT RESULTS FROM BOTH GENETIC AND EPIGENETIC CHANGES. DISCORDANT PHENOTYPES AND VARYING INCIDENCES OF COMPLEX DISEASES SUCH AS CANCER IN MONOZYGOTIC TWINS AS WELL AS GENETICALLY IDENTICAL LABORATORY ANIMALS HAVE LONG BEEN ATTRIBUTED TO DIFFERENCES IN ENVIRONMENTAL EXPOSURES. ACCUMULATING EVIDENCE INDICATES, HOWEVER, THAT DISPARITIES IN GENE EXPRESSION RESULTING FROM VARIABLE MODIFICATIONS IN DNA METHYLATION AND CHROMATIN STRUCTURE IN RESPONSE TO THE ENVIRONMENT ALSO PLAY A ROLE IN DIFFERENTIAL SUSCEPTIBILITY TO DISEASE. DESPITE A GROWING CONSENSUS ON THE IMPORTANCE OF EPIGENETICS IN THE ETIOLOGY OF CHRONIC HUMAN DISEASES, THE GENES MOST PRONE TO EPIGENETIC DYSREGULATION ARE INCOMPLETELY DEFINED. MOREOVER, NEITHER THE ENVIRONMENTAL AGENTS MOST STRONGLY AFFECTING THE EPIGENOME NOR THE CRITICAL WINDOWS OF VULNERABILITY TO ENVIRONMENTALLY INDUCED EPIGENETIC ALTERATIONS ARE ADEQUATELY CHARACTERIZED. THESE MAJOR DEFICITS IN KNOWLEDGE MARKEDLY IMPAIR OUR ABILITY TO UNDERSTAND FULLY THE ETIOLOGY OF CANCER AND THE IMPORTANCE OF THE EPIGENOME IN DIAGNOSING AND PREVENTING THIS DEVASTATING DISEASE. 2007 20 1045 37 CLINICAL CORRELATION AMONG MALE INFERTILITY AND OVERALL MALE HEALTH: A SYSTEMATIC REVIEW OF THE LITERATURE. PURPOSE: ONGOING EVIDENCE HAS SUGGESTED THE ROLE OF MALE FACTOR INFERTILITY AS A POTENTIAL PREDICTOR OF MORTALITY AND GENERAL HEALTH STATUS. THE AIM OF THE PRESENT REVIEW IS TO UPDATE THE CURRENT KNOWLEDGE BASE REGARDING THE ASSOCIATION BETWEEN MALE FACTOR INFERTILITY AND GENERAL HEALTH THROUGH A CRITICAL REVIEW OF THE LITERATURE. MATERIALS AND METHODS: A SYSTEMATIC REVIEW OF THE LITERATURE WAS CARRIED OUT FROM INCEPTION TO NOVEMBER 2019 IN ORDER TO EVALUATE SIGNIFICANT ASSOCIATIONS BETWEEN MALE INFERTILITY AND ADVERSE HEALTH OUTCOMES SUCH AS CARDIOVASCULAR, ONCOLOGIC, METABOLIC AND AUTOIMMUNE DISEASES AS WELL AS OVERALL MORTALITY. RESULTS: IN ALL, 27 STUDIES MET INCLUSION CRITERIA AND WERE CRITICALLY EXAMINED. FIVE STUDIES EXAMINED MALE INFERTILITY AND CARDIOVASCULAR DISEASE RISK, 11 EXAMINED ONCOLOGIC RISK (E.G., OVERALL CANCER RISK, TESTIS AND PROSTATE CANCER), 8 EXAMINED AGGREGATE CHRONIC MEDICAL DISEASES AND 5 INFERTILITY RELATED TO INCIDENCE OF MORTALITY, FOR A TOTAL OF 599,807 MEN DIAGNOSED WITH ANY MALE FACTOR INFERTILITY COVERING A PERIOD FROM 1916 TO 2016. CONCLUSIONS: A MAN'S FERTILITY AND OVERALL HEALTH APPEAR TO BE INTERCONNECTED. THEREFORE, A DIAGNOSIS OF MALE INFERTILITY MAY ALLOW A WINDOW INTO FUTURE COMORBIDITY AND/OR MORTALITY WHICH MAY HELP GUIDE CLINICAL DECISIONS AND COUNSELING. SEVERAL POSSIBLE ETIOLOGIES SUCH AS GENETIC, EPIGENETIC, DEVELOPMENTAL, AND LIFESTYLE-BASED FACTORS NEED TO BE FURTHER EVALUATED IN ORDER TO ESTABLISH THE UNDERLYING MECHANISMS BETWEEN MALE INFERTILITY AND HEALTH. 2020