Genetic variation at 5 new autosomal short tandem repeat markers (D10S1248, D22S1045, D2S441, D1S1656, D12S391) in a population-based sample from Maghreb region

Aim

To investigate allele distribution and genetic parameters of a population-based sample from Maghreb region.

Methods

Allele frequencies for 5 new autosomal short tandem repeat (STR) markers (D10S1248, D22S1045, D2S441, D1S1656, and D12S391) and several forensic parameters were determined for 95 unrelated individuals.

Results

The combined power of discrimination and power of exclusion for the 5 loci were high (0.9999991 and 0.9954757, respectively). Allele frequencies were compared with previously published population data. Significant differences were found between Maghreb population and all other populations at the locus D2S441. Also, significant differences were found between the Maghreb and the African American population at the D22S1045, D1S1656, and D12S391 loci, between Maghreb and Caucasian population at the D1S1656 locus, and between Maghreb and Hispanic population at the D22S1045 locus.

Conclusions

Typing of the 5 new STR loci may provide a useful addition to the previously established sets of autosomal STRs.Short tandem repeats (STR) are widely used for forensic testing. Ordinary paternity cases are solved by commercially available multiplexes kits, however, for more difficult cases, such as complex kinship analysis, additional STRs are needed to obtain better results. Besides, as many national DNA databases are growing and a large number of comparisons are being made within and between databases, concern for possible false-positive results may arise. This increases the need to introduce additional loci. The first European Standard Set (ESS) of loci included only 7 STRs loci, but the European Network of Forensic Science Institutes and the European DNA Profiling recommended to extend the ESS loci by adopting additional 3 miniSTRs loci (D10S1248, D22S1045, D2S441) and 2 additional polymorphic loci in 2006 (D1S1656, D12S391) (1,2).These new 5 loci improve the discriminatory power of forensic analysis and, by amplifying fragments well below current average amplicon sizes, can enhance genotyping success when analyzing highly degraded DNA (3,4).In order to verify and allow their use in forensics, the usefulness of ESS STR loci, it is necessary to obtain sufficient data from different populations.