Accurate STR allele designations at the FGA and vWA loci despite primer site polymorphisms.
J Forensic Sci
; 49(2): 250-4, 2004 Mar.
Article
em En
| MEDLINE
| ID: mdl-15027538
ABSTRACT
Polymerase chain reaction (PCR)-based STR DNA typing systems are used extensively in the field of human identification. Under optimal PCR conditions, the amplicon yield from both alleles of an STR locus is expected to be approximately equivalent. However, it is reasonable to expect that rare genomic sequence polymorphisms will co-localize with well-designed primer sets and induce allele imbalance or "dropouts". Two samples were identified in the course of genotyping thousands of individuals with AmpF/STR Profiler Plus that showed strong disparity in amplitude peak height of heterozygous peaks at the loci vWA and FGA. These samples were reamplified at reduced annealing temperature in an attempt to balance the peak heights. Nucleotide sequencing documented polymorphisms at the PCR primer binding sites of the affected alleles. The results indicate that reducing the annealing temperature to improve primer-binding efficiency at the mismatch and employing an alternative multiplex enhanced the data from both samples. Reducing annealing temperatures could provide a simple general solution to improving data quality for samples where polymorphisms are suspected to cause allele imbalance. Finally, we report on additional polymorphisms surrounding the vWA locus in a genetically diverse population.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sequências de Repetição em Tandem
/
Polimorfismo de Nucleotídeo Único
/
Desequilíbrio Alélico
Limite:
Humans
Idioma:
En
Revista:
J Forensic Sci
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos