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Molecular eyewitness: Forensic prediction of phenotype and ancestry

NCJ Number
Forensic ScienceInternational: Genetics Supplement Series Volume: 3 Dated: 2011 Pages: 498-499
Date Published
2 pages

This article reports on a research project that used Single Base primer Extension (SBE) technology to develop panels that include 103 ancestry and phenotype markers selected from recent literature.


When an STR DNA profile obtained from crime scene evidence does not match identified suspects or profiles from available databases, further DNA analyses targeted at inferring the possible ancestral origin and phenotypic characteristics of the perpetrator (i.e. hair color, skin color and eye color) could yield valuable information. Single Nucleotide Polymorphisms (SNPs), the most common form of genetic polymorphisms, have alleles associated with specific populations and/or correlated to physical characteristics. In the current project, DNA samples, along with corresponding ancestry/phenotype survey information and spectrophotometric skin color data, were collected from 276 anonymous volunteers of varying ethnicity, gender, and age. These samples, and additional samples of known ancestry, have been screened with the SBE panels to assess the predictive value of the candidate SNPs, with the goal of identifying the optimal panel of SNPs to efficiently assess an unknown individual's characteristics. STRUCTURE software analysis showed that individuals are classified in the expected groups. Also, Principal Component Analysis was performed for pigmentation (eye, hair, and skin) and for biogeographic ancestry of individuals. Results show that the different categories in which individuals were classified for each trait could be graphically separated with a reduced number of selected SNPs. Several SNPs provide information for both pigmentation and ancestry; thus, the researchers anticipate that it will be possible to generate informative inferences with a panel of 30–35 SNPs. (publisher abstract modified)

Date Published: January 1, 2011