Catalonian population study of the tetranucleotide repeat loci D3S1358, D8S1179, D18S51 and D19S253

Identification of more sequence variations in the D8S1179 locus

Routine STR-typing of 10,293 buccal swabs using different multiplex kits presented discordant D8S1179 profiles in four cases. Sequencing analysis identified a G-to-A transition upstream to the repeat, and an A-to-T transversion and a G-to-A transition downstream to the repeat. In the fourth case a four-base pair deletion downstream resulted in altered genotypes using different primer pairs. Current searching algorithms of the German DNA database are not capable of matching profiles that are divergent in only one STR-locus. Thus, to accommodate matching requirements and to avoid errors in individual genetic characterization for D8S1179, as described here, it is suggested that alternative primer pairs be used for routine genotyping as a matter of course.

Co-amplification of ENFSI-loci D3S1358, D8S1179 and D18S51: validation of new primer sequences and allelic distribution among 2874 individuals

The present communication presents a new triplex PCR co-amplifying three loci (D3S1358, D8S1179 and D18S51) recommended for STR typing by the European Network of Forensic Science Institutes (ENFSI). Twenty-two different primers were tested to optimise the PCR. Four of the six primer sequences finally chosen were self selected, the fifth was a published one and the sixth derived from a commercially available multiplex kit. Using this PCR-setup, even minimum amounts of genomic DNA are sufficient to analyse the STR loci D3S1358, D8S1179 and D18S51 in parallel. Especially in forensic casework, where DNA is mostly limited and often contaminated with enzyme inhibitors, this new PCR proved to be very advantageous. To demonstrate the reliability, buccal swabs from 2874 persons were typed not only with the new triplex PCR but also with a commercially available multiplex kit.