When I first started my education in forensic science, I wrote a paper about craniofacial reconstruction, which is the process of giving a face to unidentified skulls. I thought maybe I could do this because I also love to draw. My specialty is the human form, and specifically the face because that's what people pay for. However, forensic artists can't determine the color of the skin, hair, or eyes based on features of the skull so the final product will be a black and white sketch or a beige and bald clay sculpture. Then I read about a rapidly developing field of research called DNA phenotyping and it has been one of my favorite topics since.
DNA phenotyping uses single nucleotide polymorphisms (SNPs) found within or around genes linked to externally visible characteristics (EVCs). One gene that is commonly used as an EVC is amelogenin for sex determination of biological evidence. One of the coolest labs I got to do during graduate school was verify our own eye color via genotyping using IrisPlex, a DNA-based eye color prediction assay. IrisPlex uses six informative SNPs: MC1R, OCA2, SLC24A5, MATP (SLC45A2), ASIP, and TYR. Then you imput the allele into a table and it gives you a predicted phenotype for blue, intermediate, and brown eye color. We were able to accurately predict everybody's eye color that did the lab so I was impressed. Now, there is a company that does DNA phenotyping, ancestry and kinship analysis. The Snapshot Forensic DNA Phenotyping System by Parabon can generate a likely profile using DNA genotyping. This tool can be used for investigative leads when a DNA profile from an unknown sample (hopefully being from the suspect) generates no hits from the convicted offender database, as well as for missing persons, disaster victim identification, and repatriating war remains.
I strongly urge you guys to go look at the following websites. It's pretty neat!
References:
I strongly urge you guys to go look at the following websites. It's pretty neat!
References:
- http://hirisplex.erasmusmc.nl/
- https://snapshot.parabon-nanolabs.com/
- Dembinski G M, Picard C J. Evaluation of the IrisPlex DNA-based eye color prediction assay in a United States population. Forensic Science International: Genetics 9 (2014) 111-117.
Amy-
ReplyDeleteThis is a fascinating topic! I feel as if this type of DNA analysis would also be useful for law enforcement. Many times, eyewitnesses are used to compile visual information about a suspect in order to generate a sketch. But, as we know, eyewitness misidentification is one of the miscarriages of justice. If perpetrator DNA is recovered from a crime scene, DNA phenotyping could be used to assist in the composite sketch of an individual. In addition, if eyewitness testimony is used, phenotyping could be used to validate or refute the statements made by that witness. On another note, I am jealous of your eye color lab! I think it is really cool to be able to see how modern science works rather than just reading about it.
This is so cool! With DNA phenotyping, more detailed sketches can be produced, as Kaitlyn mentioned. This could really minimize the amount of time it takes to track down suspects because investigators and the public would have a more specific picture to go by. Additionally, it could be the deciding factor in finding the suspect before he or she commits another crime.
ReplyDeleteCombine it with methylation determination of age, and...there goes my hope of being a successful criminal in my retirement. I guess I'll take up golf,
ReplyDelete