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Potential Highly Polymorphic Short Tandem Repeat Markers for Enhanced Forensic Identity Testing

NCJ Number
Forensic Science International: Genetics Volume: 37 Dated: November 2018 Pages: 162-171
Date Published
November 2018
10 pages
This study explored STRs in public datasets that displayed sequence variation and may have limited allele length spread.

Due to their polymorphic nature, short tandem repeats (STRs) are well-studied and routinely used genetic markers for forensic DNA typing; however, even the largest STR multiplexes are limited in their ability to parse out individuals in a DNA mixture sample, due to alleles shared by size detected by capillary electrophoresis and challenges in resolving minor alleles from stutter, and inherent heterozygote imbalance. The current study first selected STRs using fundamental criteria of high heterozygosity, tetra-, penta-, or hexanucleotide repeat length, and overall relative narrow allele spread (based on length). All candidates were further scrutinized for chemistry compatibility. The resulting STRs were multiplexed and sequenced by massively parallel sequencing in a limited sample population set. Each candidate STR was evaluated for analytical performance and desired biological properties. The findings presented describe a refined set of 53 potential highly polymorphic STR markers (high sequence diversity and heterozygosity; reduced allele spread) that may be suitable to supplement the current core marker set(s) for possible enhanced characterization of complex DNA profiles. (publisher abstract modified)

Date Published: November 1, 2018