Importance of Autosomal and Y-STR Markers in Establishing Sibling Relationship by DNA Genotyping

The aim of the present study was the identification of an unknown person found in an advanced decomposed state using DNA samples provided by two alleged brothers as reference samples. To obtain an increased reliability of the test, we used autosomal and Y-STR markers.

Tissue fragments were obtained for the DNA isolation during the autopsy examination from the unidentified person. DNA was isolated from the reference samples obtained from buccal swabs of the two alleged brothers. The DNA was isolated from the biological samples using PureLink Genomic DNA (Invitrogen, USA). The quantification of the DNA samples was done on an ABI 7500 real-time PCR system with HID Analysis software v1.2 incorporated. For DNA amplification we used the multiplex PCR kit AmpFlSTR Identifiler Plus Kit for autosomal STR markers and AmpFlSTR Y-filer PCR Amplification Kit for the Y-STR markers. Further, we separated the DNA products on an ABI 3500 genetic analyzer. Gene Mapper ID-X version 1.4 software was used to visualize the DNA fragments. Data interpretation was done using the Kinship Examination of GenoProof-3 (qualitype, Dresden, Germany).

We obtained genetic profiles for the three alleged brothers on autosomal and Y-STR markers and, thus, could establish a full sibling relationship between them.

Since the introduction of DNA in human identification, it represents a useful tool in establishing sibling relationship from different biological samples.