FGA Locus DNA Sequence Testing as Personal Identification

Short tandem repeat (STR) DNA, one of which is the FGA locus, can be used as a profiling tool for personal identification analysis in the forensic field because it has many allelic combinations based on the complex repetitive pattern of DNA sequences. The FGA locus was reported to have the highest discrimination power in the Indonesian population. The aim of this study was to understand the ability of personal discrimination from the FGA locus sequences in a DNA forensics testing scenario of Indonesian subjects. The specimens were used towels (T), toothbrushes (TB), and hair ties (HT) from certain people and buccal swabs (BS) from the same people and two others as controls whose identities were analyzed. DNA extraction using the Phenol CIAA ( chloroform isoamyl-alcohol ) method followed amplification of the DNA of FGA loci that targeted repetitive sequences, agarose gel electrophoresis, and Sanger sequencing of FGA loci. The amplification showed the DNA bands from the FGA loci were around 350 bp. The sequencing results showed that the number of repetitions of the FGA allele from samples T, TB, and HT was identical to BS1, which was 19 repetitions, while BS2 and BS3 were 22 and 21 repetitions, respectively. Thus, the sample items T, TB, and HT are owned by individual BS1. The FGA gene sequenced by the Sanger method can be used in a limited way, only detecting repetitive sequences on the longest allele as a differentiator between one individual and another.