FORENSIC SCIENCE INTERNATIONAL: GENETICS SUPPLEMENT SERIES
Abstract
NGS has the potential to be a promising technology for recovering genetic information from challenging
specimens in forensic genetics. In order to understand the role of DNA damage on the outcome of NGS, we
investigated the performance of ForenSeqTM DNA Signature kit, Illumina (in its pre-commercial version)
on a set of in vitro degraded trial DNA samples. After DNA quantification by qPCR, duplicate analyses of
the samples were carried out. The resulting molecular products were then sequenced by using MiSeq1
system (Illumina) and analyzed using ForenSeqTM Universal Analysis Software (Illumina). The coverage
and error rate of the NGS data obtained from the degraded samples were compared to the ones gathered
from the unmodified DNA. The NGS data showed that the ability of recovering genotypes and the
frequency of analytical artifacts are strongly influenced by the degree of damage of the template. NGS was
able to call 46–17% of the STR loci and 68–26% of the SNPs in the degraded samples. In addition, when the
genotypes from the degraded samples were compared to the ones recovered from the unmodified control
DNA, correct typing was achieved from 39 to 4% of the STRs and from 55 to 13% of the SNPs.
These data show that NGS is a powerful method for gathering genetic data from samples which failed
the conventional approaches, even if in this experiment the risk of mistyping seems not to be negligible
(up to 2%).
