Single nucleotide polymorphism-short tandem repeat analysis system for Japanese people

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K10515
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 58040:Forensics medicine-related
• Research Institution: Tohoku University
• Principal Investigator: Ohuchi Tsukasa 東北大学, 医学系研究科, 技術専門職員 (90712266)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 個人識別 / SNP-STR / Compound marker

Outline of Final Research Achievements

In forensic practice, DNA typing is mainly performed targeting highly polymorphic short tandem repeats (STRs). However, it is expected that the discrimination ability can be improved by adding information on single nucleotide polymorphisms (SNPs) adjacent to STRs.
In this study, we targeted nine STR loci and their adjacent SNPs based on DNA polymorphism information of Japanese and attempted to construct a reaction system using the widely used capillary electrophoresis (CE) method. As a result, correct typing was possible at eight loci. It was suggested that this method could contribute to improving the accuracy of DNA typing.

Free Research Field

法医学

Academic Significance and Societal Importance of the Research Achievements

従来のCE法によるSTR検査はSTRの反復数（長さ）のみが対象で、STRの塩基配列そのもの並びにSTRに隣接するSNPを識別できない点で改善の余地が残されている。近年開発された超並列シーケンシング（Massively Parallel Sequencing；MPS）法は同問題を一挙に解決可能だが、コスト面から各鑑定機関で運用することは現実的でない。
本研究では各鑑定機関で実施可能なCE法を利用して精度向上を図るため、STRの反復数に加えSNPを同時に識別する反応系の構築を試みた。結果としてSNP情報を追加した検査が可能となり、実務レベルでより詳細なDNA型鑑定が可能となると期待された。