Scattered Episode 18: Predictive Modelling with DNA – Interview with Dr. Ellen Greytak

Dr. Ellen McRae Greytak is Director of Bioinformatics at Parabon NanoLabs, Inc.
“Parabon NanoLabs, Inc. (Parabon) is a vertically integrated DNA technology company that develops next-generation therapeutic and forensic products by leveraging the enormous power of DNA.” (from

The Globe and Mail, Alberta edition from August 27, 2022.

Parabon came to my attention when I read a newspaper article about how Calgary Police detectives used Parabon’s services to crack two sexual assault cases decades cold.

I reached out to Parabon to learn more and I’m very glad I did. This interview was incredibly enlightening because I’d never heard of the technique they are using.

In this episode we talk about:

  • how Parabon originated and the services it provides
  • the research Parabon did to develop a predictive model to estimate a person’s appearance based on their DNA
  • how clinical DNA is different from forensic DNA and how that difference impacts predictions based on forensic DNA
  • the difference between genotype (genetic code) and phenotype (what a person looks like), and that the existence of a genetic allele in a person’s genetic code doesn’t determine the expression of a certain physical attribute in a person
  • the difference between the commonly known DNA processes of identifying an unknown individual and Parabon’s technique
  • developing and using a predictive model to estimate a person’s appearance from their DNA, including what the person won’t look like
  • that mixed or degraded forensic DNA samples may impact the prediction of the unknown perpetrator’s appearance
  • how DNA is merely one of many tools detectives use to identify unknown individuals
  • the Snapshot Study and how it combines a volunteer’s DNA with photos to help increase the accuracy of Parabon’s predictive models for estimating the appearance of an unknown subject
  • JusticeDrive crowdfunding to allow the work to continue on cases

Dr. Greytak wishes to note “…[T]he information Parabon provides is a lead, and the final identity confirmation is done through traditional forensic DNA analysis using STRs. However, there are occasions in unidentified remains cases where there is no known DNA available from the decedent. In those cases, we have had medical examiners find a close relative, and then we perform kinship analysis using SNPs, which they can use to close the case.”

Correction: when I said there are “thousands” of unidentified remain in Canada, I was thinking of the number of missing. The Government of Canada reports that, as of 2021, there were 31,240 adults missing in Canada. As of March 23, 2023, there are 228 reported unidentified remains in Canada. You can review them here and here.

You can learn more about the Snapshot Study here: (US only)

You can learn more about the JusticeDrive here: (international welcome)

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