DNA Assay Development and Validation for Pigment-Related Features to Assist in the Identification of Missing Persons and Human Remains

• NCJ Number: 242774
• Author(s): Elisa Wurmbach, Ph.D.
• Date Published: June 2013
• Length: 53 pages
• Grant Number(s): 2010-DN-BX-K181
• Agencies: NIJ-Sponsored
• Publication Type: Report (Study/Research); Report (Grant Sponsored)

Annotation

This project designed and validated an assay that predicts eye and skin color based on DNA, which can assist in the identification of missing persons and human remains.

Abstract

The study succeeded in identifying seven single nucleotide polymorphisms (SNPs) located in or nearby pigmentation genes that can be used to describe the eye and skin color based solely on DNA. Five of the seven SNPs are potentially causative; three cause missense mutations and two SNPs are directly located in predicted transcription factor binding sites. The other two SNPs are located in introns, and it is still unclear whether they are causative. Six of the seven SNPs are used to predict the eye color, which distinguishes among brown, green, not blue (green or brown) and not brown (green or blue). All seven SNPs can be used to predict skin coloration of individuals, distinguishing between not-white (light brown or dark) and not dark (light brown or white). Both tests can be applied to various populations, including African-American, East Asian, South Asian, European, and mixed populations. The error rates for both predictors are low: 3 percent for the eye color predictor and 1 percent for the skin color predictor. Recently, the seven-plex system was improved by adding one SNP (rs12896399), which is located in the 5'-region of SLC24A4, and by changing the instructions. More precise predictions were achieved by including blue to the eye colors and light to the skin colors. The number of positive descriptions was also significantly increased while keeping the error rates low (approximately 5 percent). These eight SNPs were integrated into a forensic kit that is easy, fast, and inexpensive. It is possible to apply this assay on degraded DNA that is typically found in decomposed human remains. 6 figures, 1 table, and 62 references