Identification and Characterization of Variant Alleles at CODIS STR Loci

    Volume 50, Issue 5 (September 2005)

    ISSN: 0022-1198


    Published Online: 17 August 2005

    Page Count: 6

    Allor, C

    Einum, DD
    Orchid Biosciences, Inc., East Lansing, MI

    Scarpetta, M
    Orchid Biosciences, Inc., East Lansing, MI

    (Received 22 January 2005; accepted 7 May 2005)


    Short tandem repeat (STR) profiles from 32,671 individuals generated by the ABI Profiler Plus and Cofiler systems were screened for variant alleles not represented within manufacturer-provided allelic ladders. A total of 85 distinct variants were identified at 12 of the 13 CODIS loci, most of which involve a truncated tetranucleotide repeat unit. Twelve novel alleles, identified at D3S1358, FGA, D18S51, D5S818, D7S820 and TPOX, were confirmed by nucleotide sequence analysis and include both insertions and deletions involving the repeat units themselves as well as DNA flanking the repeat regions. Population genetic data were collected for all variants and frequencies range from 0.0003 (many single observations) to 0.0042 (D7S820 ‘10.3’ in North American Hispanics). In total, the variant alleles identified in this study are carried by 1.6% of the estimated 1 million individuals tested annually in the U.S. for the purposes of parentage resolution. A paternity case involving a recombination event of paternal origin is presented and demonstrates how variant alleles can significantly strengthen the genetic evidence in troublesome cases. In such instances, increased costs and turnaround time associated with additional testing may be eliminated.

    Paper ID: JFS2005024

    DOI: 10.1520/JFS2005024

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    Title Identification and Characterization of Variant Alleles at CODIS STR Loci
    Symposium , 0000-00-00
    Committee E30