RESUMO
Pairs of individuals tested at the 13 CODIS core STR loci to determine sibship were used as a source of familial data that was seeded into a larger data set of 12,000 plus DNA profiles simulating a CODIS-like offender database. To determine whether known sibs could be found in the larger database two methods were used: degree of allele sharing and a kinship matching approach. The allele sharing method detected 62 of 109 of the known sib pairs (57%) while kinship matching detected 90 of the sib pairs (83%). Although kinship matching was the more efficient method of the two, the number of false positives generated prior to finding a true match was inversely related to the likelihood of sibship suggesting that many true siblings would not be easily found in a large forensic database via familial searching techniques.
Assuntos
DNA/genética , Bases de Dados de Ácidos Nucleicos/normas , Família , Genética Forense/métodos , Irmãos , DNA/química , DNA/isolamento & purificação , Impressões Digitais de DNA/legislação & jurisprudência , Impressões Digitais de DNA/métodos , Genética Forense/normas , Humanos , Repetições de Microssatélites/genéticaRESUMO
Fifty known siblings and fifty unrelated pairs were genotyped using the ABI Identifiler STR system and sibship indices computed for each pair. Combined sibship indices (CSIs) for the known siblings ranged from less than 10 to greater than 1 billion. CSIs for the unrelated pairs ranged from 4.5 x 10(-8) to 0.12. In the known sibling group the percentage of loci where both alleles matched was approximately 40%, while the percentage of loci where neither matched was approximately 10%. In the non-sibling group, the percentage of loci where both alleles matched was approximately 6%, while the percentage of loci where neither matched was approximately 45%. Interestingly, the percentage of loci where a single allele matched was the same in both the known siblings and unrelated pairs, approximately 50%.
