Characterization of the variant allele 9.2 of penta D locus

Abstract

DNA profiles of forensic cases of Córdoba Province, Argentina, typed by PowerPlex® 16 kit (Promega), have shown in the Penta D locus few samples with a variant allele migrating as an off ladder between alleles 9 and 10. In order to determine the molecular basis of the new variant allele, three samples were subject to polymerase chain reaction amplification of the Penta D locus by monoplex, and were further purified and sequenced. The sequence analysis revealed that the off ladder allele has ten repeats motifs AAAGA as allele 10, with three nucleotides (TAA) deletion in the 3′ flanking region, 128 nucleotides after the last repeat. Therefore, the variant allele could be explained by a deletion of allele 10, and was designated 9.2. Mse I digestion assay allows to corroborate allele 9.2 without sequencing. A population study in Córdoba Province indicates that allele 9.2 of Penta D locus has a frequency of 0.0063. © 2007 American Academy of Forensic Sciences.