A novel approach for genotyping of LCN-DNA recovered from highly degraded samples

Nowadays Short Tandem Repeats Polymorphisms are the most utilized genetic markers in forensic biology. A new kind of STRs profiling system is based on the amplification of shorter fragments compared to the conventional STR multiplexes; because of their length, these “Mini” STR amplicons could be obtained even from extremely degraded DNA and/or from few copies of template DNA. Mini STR kits for Human Identification have been already validated and placed on the market; moreover they are related to those loci which are commonly detected by traditional STRs kits, allowing comparison between data yielded with both methods. In this paper we report a homicide casework occurred in the South of Italy: a young guy was killed and then burnt. Nothing inside could be collected apart a burnt stub which was subjected to a comparative genotype analysis between STRs and MiniSTRs in order to verify efficiency and discrimination power of the latter ones. Our results show that MiniSTRs permit a reliable determination of 9 human allelic loci whereas traditional STRs typing protocols offer only a partial resulting genotyping profile. MiniSTRs turned out to be more robust and sensitive markers than the traditional ones. In the next future we aim to apply this method to several kinds of degraded samples in order to confirm the above mentioned observations.