Here’s why identical twins aren’t 100% alike at least when you’re looking at their DNA.

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The difference between identical and fraternal twins.

American Academy of Pediatrics.https://www.healthychildren.org/English/family-life/family-dynamics/Pages/The-Difference-Between-Identical-and-Fraternal-Twins.aspxOpens a new window[Accessed February 2025]

Chen N et al.

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Risk factors associated with monozygotic twinning in offspring conceived by assisted reproductive technology.

Human Reproduction 4:035https://academic.oup.com/hropen/article/2023/4/hoad035/7273786Opens a new window[Accessed February 2025]

Jarry J.

Identical twins are not identical.

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Office for Science and Society.https://www.mcgill.ca/oss/article/general-science/identical-twins-are-not-identicalOpens a new window[Accessed February 2025]

Jonsson H et al.

Differences between germline genomes of monozygotic twins.

Nature Genetics 53: 27-34.https://www.nature.com/articles/s41588-020-00755-1Opens a new window[Accessed February 2025]

Kadam N et al.

mirror twins

Odds and predictors of monozygotic twinning in a multicentre cohort of 25,794 IVF cycles.

What is epigenetics?https://medlineplus.gov/genetics/understanding/howgeneswork/epigenome/Opens a new window[Accessed February 2025]

NIH.

Is the probability of having twins determined by genetics?

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National Institutes of Health, National Library of Medicine.

MedlinePlus.https://medlineplus.gov/genetics/understanding/traits/twins/Opens a new window[Accessed February 2025]

Roberts AD et al.

Incidence of monozygotic twins in blastocyst and cleavage stage assisted reproductive technology cycles.

Can triplet babies be identical?

Fertility and Sterility.https://www.vcrmed.com/wp-content/uploads/2013/06/MZT-paper-corrected-proofs.pdfOpens a new window[Accessed February 2025]

UCSF.

Differentiating between monozygotic twins in forensics through next generation mtGenome sequencing.

Reproductive and Placental Research Unit.https://medicine.yale.edu/obgyn/kliman/placenta/twins/Opens a new window[Accessed February 2025]

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Karen Miles