New DNA sequencing technologies have been used to identify the historical remains of individuals from the Washington family buried in an unmarked cemetery in West Virginia in the mid-1800s. The researchers plan to apply these techniques to identify the remains of service members lost in past conflicts. This case allowed them to test methods for extended kinship prediction and improve methodologies for identifying degraded DNA samples. The Department of Defense’s human remains DNA laboratory, AFMES-AFDIL, is leading these efforts to identify service members from past conflicts going back to World War II.
The researchers performed a range of DNA tests on the recovered remains, along with analyses of the DNA from a living descendant, in order to confirm the identities of the individuals. They used Y chromosome DNA analysis to assess paternal relationships, mitochondrial DNA sequencing to assess maternal relationships, and a novel method to analyze next-generation sequencing data to predict more distant ancestry. Pairwise kinship comparisons between the living descendant and the buried individuals revealed relationships closer than anticipated, which was attributed to cross-cousin marriages in the Washington family tree.
The team was able to confirm the identities of the three sets of remains and determine which male was the direct ancestor of the living descendant. The newly developed methods for DNA analysis open up new possibilities for making positive identifications in cases involving heavily degraded DNA, such as remains preserved with embalming techniques involving formaldehyde. These methods will allow for expanded use of family reference samples from 3rd and 4th degree relatives, increasing the number of DNA-assisted identifications, especially for service members lost in past conflicts like World War II, Korea, the Cold War, and Vietnam.
The most common method used for DNA profiling in forensics, short tandem repeat (STR) analysis, is often ineffective for heavily degraded remains. The newly developed SNP methods allow for positive identification from nuclear DNA and the expansion of the pool of viable family reference sample donors. This will enable more DNA-assisted identifications, particularly for remains from past conflicts that have undergone significant degradation over time. The research was published in the journal iScience on March 28, highlighting the importance of using new DNA sequencing technologies to identify historical remains and advance forensic identification efforts.
