Identical twins carry a persistent epigenetic signature of early genome programming.
Jenny Van DongenScott D GordonAllan F McRaeVeronika V OdintsovaHamdi MbarekCharles E BreezeKaren SugdenSara LundgrenJuan E Castillo-FernandezEilis J HannonTerrie E MoffittFiona A HagenbeekCatharina E M van BeijsterveldtJouke- Jan HottengaPei-Chien Tsainull nullnull nullJosine L MinGibran HemaniErik A EhliFranziska PaulClaudio D SternBastiaan T HeijmansPieternella Eline SlagboomLucia DaxingerSilvère M van der MaarelEco J C N de GeusGonneke WillemsenGrant W MontgomeryBruno ReversadeMiina OllikainenJaakko A KaprioTimothy D SpectorJordana T BellJonathan S MillAvshalom CaspiNicholas G MartinDorret I BoomsmaPublished in: Nature communications (2021)
Monozygotic (MZ) twins and higher-order multiples arise when a zygote splits during pre-implantation stages of development. The mechanisms underpinning this event have remained a mystery. Because MZ twinning rarely runs in families, the leading hypothesis is that it occurs at random. Here, we show that MZ twinning is strongly associated with a stable DNA methylation signature in adult somatic tissues. This signature spans regions near telomeres and centromeres, Polycomb-repressed regions and heterochromatin, genes involved in cell-adhesion, WNT signaling, cell fate, and putative human metastable epialleles. Our study also demonstrates a never-anticipated corollary: because identical twins keep a lifelong molecular signature, we can retrospectively diagnose if a person was conceived as monozygotic twin.