Summary of this article

Is it possible to use DNA analysis to determine if a sibling with identical twins is the father? This section details the genetic similarities and limitations of the test.

If identical twin brothers are potential fathers, it is very difficult or impossible to determine the father in a prenatal paternity test. This is due to the following reasons

DNA characteristics of identical twins.

Identical DNA: identical twins arise from the division of identical fertilized eggs and therefore have almost identical DNA sequences. Therefore, STR markers and other genetic analysis methods used in standard DNA identification cannot distinguish between two people.

Issues in prenatal paternity testing.

Identity: if there are identical twin prospective fathers, the fetal DNA obtained from the prenatal paternity test cannot distinguish which twin it was inherited from .As both twins are equally likely to be the father, the results of the test will not help to identify the father.

Possible solutions.

Additional evidence or information: in order to identify the father, additional evidence or information other than DNA evidence (e.g. duration of the relationship or other circumstantial evidence ) may be required. However, this too may not be scientific evidence, but only a legal determination.
Epigenetic markers and mutations: recent studies have attempted to differentiate twins using epigenetic differences and a small number of novel mutations that occur between identical twins, but these methods are very limited and are not yet widely used for general appraisal.

Summary

When identical twins are potential fathers, it is very difficult to identify which one is the father in a prenatal paternity test and cannot be distinguished by normal DNA testing. At present, it is understood that it is difficult to identify the father, as it is only possible to rely on non-DNA evidence and very sophisticated genetic analysis methods.

医師監修監修日：2024年8月28日

岡博史（おかひろし）

医師・医学博士／ヒロクリニック統括院長

YouTubeチャンネルなどを通じて、遺伝子やNIPT（新型出生前診断）についてわかりやすく発信しています。

略歴

1996年慶應義塾大学医学部卒業
2004年慶應義塾大学医学博士号取得
2005年慶應義塾大学皮膚科学教室助手
2008年ヒロ皮フ形成クリニック開業
2009年医療法人社団福美会理事長
2015年医療法人社団福美会理事

資格・所属

CAPラボディレクター
日本皮膚科学会皮膚科専門医
日本医師会産業医
東京衛生検査所指導監督医

発信・関連リンク

この記事は、ヒロクリニックNIPPTの編集・監修体制にもとづき、資格を持つ医師が内容を確認しています。

医師監修監修日：2024年8月28日

堤修一（つつみしゅういち）

医師・医学博士／ヒロクリニック博多駅前院院長

略歴

1993年東京大学医学部医学科卒業
2016〜2019年東京大学先端科学技術研究センター准教授

発信・関連リンク

プロフィール詳細

この記事は、ヒロクリニックNIPPTの編集・監修体制にもとづき、資格を持つ医師が内容を確認しています。

参考文献

Weber-Lehmann J, Schilling E, Gradl G, Richter D, Wiehler J, Rolf B. Finding the needle in the haystack: Differentiating "identical" twins in paternity testing by ultra-deep next generation sequencing. Forensic Sci Int Genet. 2014 Mar;9:42-6.
Jonsson H, Magnusdottir E, Eggertsson HP, Halldorsson BV, Helgason H, Kehr B, et al. Differences between germline genomes of monozygotic twins. Nat Genet. 2021 Jan;53(1):27-34.