As 2018 comes to a close, we reflect back on the substantial advancements made this year to bring massively parallel sequencing (MPS) into mainstream forensic use. Here is a sampling of some of the major milestones this year:
MPS Data Uploaded to a National Database
France became the first country to upload MPS generated profile data to its national DNA database. The INPS (Institut National de Police Scientifique) laboratory in Lyon, which started using the MiSeq FGx® Forensic Genomics System for casework in 2017, uploaded their first MPS DNA profiles in February of 2018. They had recovered additional autosomal STR data for two low level minor male contributors in a 2011 homicide cold-case. These data could not be conclusively obtained with previous CE-based analysis, further validating the utility of MPS as a more effective method of typing biological evidence samples.
Although no database "hit" (match) has yet occurred for that case, the INPS Lyon laboratory is ramping up MPS casework in 2019 and plans to start uploading a higher volume of MiSeq FGx-generated profiles in the near future. Therefore, it is only a matter of time until the first database hit from MPS-generated data occurs.
Sequence-based STR Allele Frequencies Published by NIST
The U.S. National Institute of Standards and Technology (NIST) published sequence-based autosomal STR allele frequencies for the "NIST 1036" population sample set using the ForenSeq® DNA Signature Prep Kit and the MiSeq FGx instrument platform. This allows statistical weight (i.e. match statistics) to be calculated for the many additional alleles revealed by sequencing, using the same sample set which is already the basis for population statistics in many U.S. forensic laboratories.
The paper, published in Forensic Science International: Genetics, reported sequence-based allele frequencies for 1036 samples across the 27 autosomal STR loci included in the ForenSeq Kit. The 1036 samples were the same as those used in previous NIST studies characterizing length-based allele frequencies in four U.S. populations: African American, Asian, Caucasian, and Hispanic.
As expected, NIST detected a substantial increase in unique alleles by sequence as compared to length alone. This increase demonstrates the prevalence of alleles that share the same length but not the same sequence, also called isometric heterozygotes. One of the major advantages of MPS over CE length-based typing is the ability to see these subtle, but impactful, differences between samples and contributors within mixtures.
SWGDAM Interpretation Guidelines
Earlier this year, the NDIS procedures board chair requested that the Scientific Working Group on DNA Analysis Methods (SWGDAM) generate interpretation guidelines specifically for autosomal STR and mitochondrial MPS typing. Those interpretation guidelines were drafted by the SWGDAM NGS Working Group and are expected to be published in early 2019.
FBI NDIS approval is expected to follow shortly for the MiSeq FGx Forensic Genomics System, enabling it to be used by laboratories generating DNA profiles for upload to the U.S. National DNA Index System (NDIS). This will remove yet another barrier for U.S.-based forensic labs to adopt MPS into their casework operations, and allow them to utilize federal funding from the National Institute of Justice for implementation.
Verogen Goes Global
Verogen, the first DNA sequencing company solely focused on forensic applications, went live globally, launched several user-requested products, and forged partnerships with established robotics companies such as Aurora Biomed and Hamilton Robotics to automate library preparation. The formation of a global independent company entirely focused on this application is the best way to fully address the unique needs of forensic laboratories and unlock the true potential of forensic genomics.
With that aim in mind, Verogen hosted the 4th annual DNA Evidence to Investigative Insights Conference in Barcelona in October. This event brought together forensic scientists from 37 institutes and 19 countries to share their experiences in all aspects of MPS and its implementation into routine forensic operations. The conference showcased the many different ways – from STR and mtDNA casework, through RNA profiling and metagenomics, to wildlife forensics and molecular autopsy – that MPS can be leveraged for forensic investigations.
2018 has been a busy and productive time for massively parallel sequencing. Next year will bring even more exciting progress and we look forward to sharing it.
Are you or your lab making progress with MPS? Tell us about it and we can highlight your efforts here!