Cited by 3,602Epigenetics and DNA MethylationGenetic Syndromes and ImprintingAssisted Reproductive Technology and Twin Pregnancy

Epigenetic differences arise during the lifetime of monozygotic twins

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Fraga, Mario F., Ballestar, Esteban, Paz, Maria F., Ropero, Santiago, Setien, Fernando, Ballestar, Maria L., Heine-Suñer, Damia, Cigudosa, Juan C. +13 more·2005·Proceedings of the National Academy of Sciences

Abstract

Monozygous twins share a common genotype. However, most monozygotic twin pairs are not identical; several types of phenotypic discordance may be observed, such as differences in susceptibilities to disease and a wide range of anthropomorphic features. There are several possible explanations for these observations, but one is the existence of epigenetic differences. To address this issue, we examined the global and locus-specific differences in DNA methylation and histone acetylation of a large cohort of monozygotic twins. We found that, although twins are epigenetically indistinguishable during the early years of life, older monozygous twins exhibited remarkable differences in their overall content and genomic distribution of 5-methylcytosine DNA and histone acetylation, affecting their gene-expression portrait. These findings indicate how an appreciation of epigenetics is missing from our understanding of how different phenotypes can be originated from the same genotype.

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Crossref · 10.1073/pnas.0500398102

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  • Genetics alone do not account for most of the risk of major depression.

    “genetics alone do not account for most of the risk of major depression.”

    From Epigenetic regulation in major depression and other stress-related disorders: molecular mechanisms, clinical relevance and therapeutic potential (2023) · cites this paper as [17]

    The introduction (page unavailable) says genetically identical twins can differ in psychiatric disease and names schizophrenia and bipolar disorder; the Discussion links twin differences to environmental and epigenetic factors. This supports the general point that genetics is not the only factor, but the paper does not address major depression or establish that genetics accounts for less than half its risk. (LLM, conf=0.82)

    Experimental — accuracy not yet measured
  • Environmental conditions clearly influence epigenetic profiles in human immune cells, and some studies have linked immune cell DNA methylation profiles to specific social environmental conditions such as low social status and early life stress exposure.

    “Environmental conditions clearly influence epigenetic profiles in human immune cells [37], and some studies have begun to link immune cell DNA methylation profiles to specific social environmental conditions such as low social status [7] and early life stress exposure [38]–[41].”

    From Human Social Genomics (2014) · cites this paper as [37]

  • Identical twin studies show a high discordance rate for major depressive disorder of 50%, indicating the importance of non-genetic factors.

    “Identical twin studies have shown a high discordance rate for MDD of 50%, indicating the importance of non-genetic factors.”
  • Studies with monozygotic twins suggest the accumulation of epigenetic changes as twins age (e.g., demethylation of 5-methylcytosines in DNA), thus affecting the transcriptome.

    “Studies with monozygotic twins suggest the accumulation of epigenetic changes as twins age (e.g., demethylation of 5-methylcytosines in DNA), thus affecting the transcriptome (Fraga et al., 2005).”

    From The Search for Antiaging Interventions: From Elixirs to Fasting Regimens (2014) · cites this paper as Fraga et al., 2005

  • Identical twins diverge over the life course in patterns of CpG methylation of their DNA reflecting the influence of non-shared experiences.

    “For example, identical twins diverge over the life course in patterns of CpG methylation of their DNA reflecting the influence of “non-shared” experiences.”

    From Neurobiological and Systemic Effects of Chronic Stress (2017) · cites this paper as [76]

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Research works printed but not linked: 1

  1. Hall, J. G. & Lopez-Rangel, E. (1966) in Twins and Twinning, eds. Emery, A. E. H. & Rimoin, D. L. (Churchill Livingstone, New York), pp. 395-404.

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Authors
Fraga, M. F., Ballestar, E., Paz, M. F., Ropero, S., Setien, F., Ballestar, M. L., Heine-Suñer, D., Cigudosa, J. C., Urioste, M., Benitez, J., Boix-Chornet, M., Sanchez-Aguilera, A., Ling, C., Carlsson, E., Poulsen, P., Vaag, A., Stephan, Z., Spector, T. D., Wu, Y.-Z., Plass, C., & Esteller, M.
Affiliations
  • Universitat de València (ES)
  • Epigenetics, Cytogenetics, and Genetic Laboratories, Spanish National Cancer Centre (CNIO), Melchor Fernandez Almagro 3, 28029 Madrid, Spain; Department of Behavioral Science, University of Valencia, 46010 Valencia, Spain; Molecular Genetics Laboratory, Genetics Department, Son Dureta Hospital, 07014 Palma de Mallorca, Spain; Department of Clinical Sciences, University Hospital Malmö, Lund University, S-205 02 Malmö, Sweden; Steno Diabetes Center, 2820 Gentofte, Denmark; Twin Research and Genetic...
Venue
Proceedings of the National Academy of Sciences
Published
2005-07-11
Volume
102
Issue
30
Pages
10604-10609
ISSN
  • 0027-8424 (ISSN-L)
  • 1091-6490
OpenAlex
W2134555277
Cited by
3,602
References
19
Citations by year
2026: 65 · 2025: 87 · 2024: 113 · 2023: 115 · 2022: 143 · 2021: 119 · 2020: 147 · 2019: 161 · 2018: 185 · 2017: 173 · 2016: 191 · 2015: 225 · 2014: 223 · 2013: 242 · 2012: 293
FWCI
51.76
Type
journal article
Language
en
Open access
Locations
  • Proceedings of the National Academy of Sciences (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Dipòsit Digital de la Universitat de Barcelona (Universitat de Barcelona) (submittedVersion, public-domain)
  • Hispana (submittedVersion)
  • Docusalut (Conselleria de Salut i Consum del Govern de les Illes Balears) (submittedVersion)
  • Research Portal (King's College London) (submittedVersion)
  • Lund University Publications (Lund University) (submittedVersion)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Epigenetics and DNA Methylation
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Genetic Syndromes and Imprinting
  • Health Sciences › Medicine › Pediatrics, Perinatology and Child Health › Assisted Reproductive Technology and Twin Pregnancy
Keywords
monozygotic twins, epigenetic variation, DNA methylation, histone acetylation, 5-methylcytosine, phenotypic discordance, gene expression, aging
MeSH terms
Acetylation, Adult, Analysis of Variance, Female, Histones, Humans, Male, Phenotype, Surveys and Questionnaires, Spain, Twins, Monozygotic, Restriction Mapping, Sequence Analysis, DNA, Gene Expression Regulation, Developmental, Electrophoresis, Capillary, DNA Methylation, Reverse Transcriptase Polymerase Chain Reaction, Oligonucleotide Array Sequence Analysis, Nucleic Acid Amplification Techniques, Epigenesis, Genetic, 5-Methylcytosine, X Chromosome Inactivation

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