Evaluation of the Utility of Mitochondrial DNA Testing in Personal Identification Work in the Great East Japan Earthquake of 2011.

Although the Great East Japan Earthquake occurred on March 11, 2011, identification of victims is still ongoing. Typically, mitochondrial DNA (mtDNA) is performed when it is difficult to identify an individual using nuclear DNA. In Japan, samples from criminal investigations are subjected to nuclear DNA testing at the Scientific Research Institute belonging to each prefectural police headquarters, while all mtDNA tests were originally conducted at the National Research Institute of Police Science. However, the appraisal work using mtDNA became more time-consuming as the number of target samples increased. Because our department is capable of performing mtDNA testing, the Miyagi Prefectural Police requested that our department perform mtDNA testing. Specifically, we focused on 16 individuals as putative candidates for 11 unidentified human remains; efforts to identify these remains were performed using samples from 20 relatives. These efforts positively identified six victims. This included confirmation that one corpse had originally been identified incorrectly. Although disasters of a similar scale can strike Japan again, there are limited facilities that can consistently perform mtDNA testing. Expensive sequencing machines and properly trained operators are essential for mtDNA testing, but they cannot be established at the forensic departments of all medical schools. There is thus an urgent need to establish core facilities at appropriate sites, such as Tohoku University in the Tohoku Region, to build a mtDNA testing system suitable for the aftermath of any disaster.