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Monozygotic Twins and Epigenetics

Epigenetic Regulation and Epigenomics

  1. Jean-Sébastien Doucet1,
  2. Albert H. C. Wong2

Published Online: 15 MAY 2012

DOI: 10.1002/3527600906.mcb.201100030

Reviews in Cell Biology and Molecular Medicine

Reviews in Cell Biology and Molecular Medicine

How to Cite

Doucet, J.-S. and Wong, A. H. C. 2012. Monozygotic Twins and Epigenetics. Reviews in Cell Biology and Molecular Medicine. .

Author Information

  1. 1

    University of Toronto, Centre for Addiction and Mental Health, Department of Pharmacology, Toronto, Ontario, Canada

  2. 2

    University of Toronto, Centre for Addiction and Mental Health, Departments of Psychiatry and Pharmacology, Faculty of Medicine, Toronto, Ontario, Canada

Publication History

  1. Published Online: 15 MAY 2012


Twins have been the subject of both art and scientific investigation for millennia. Twins allow the exploration of the impact of genes and the environment on phenotypic traits, and are important for studying the etiology of disease. Whilst traditional genetic studies have relied on twins as a particularly informative type of family structure, twins have more recently become crucial for exploring epigenetics – the potentially reversible DNA and chromatin modifications (e.g., methylation and acetylation) that regulate gene expression and other genomic functions. Such modifications may ultimately affect the amount, timing, and location of protein expression, which may have an equally major impact on phenotype as do protein-coding structural mutations. Monozygotic twins have near-identical DNA sequences, and offer unique opportunities to study epigenetic effects on phenotype, and the way in which epigenetic information is modified and maintained. The epigenetic code may also be transmitted across generations although, unlike the DNA code, epigenetic modifications may be modified by environmental inputs. Consequently, monozygotic twins become even more important for investigating the dynamic regulation and function of the epigenetic code.


  • Monozygotic twins;
  • Dizygotic twins;
  • Epigenetic;
  • Epigenome;
  • Phenotype