Report on the Use of Autosomal STR Markers in Resolving a Kinship Case

Genetic identification is now a standard and efficient method for identifying individuals and investigating claimed kinship cases. The aim of this study was to investigate the relationship between Y-STR and autosomal STR markers.

This case report is according to a claimed kinship that was done with available sampling of 7 relatives referred to forensic medicine in 2020. These members were 2 men and 2 women without identity cards and 3 men with identity cards claiming the uncle-nephew and aunt-nephew relationships. After authentication and obtaining the complete biographies of the nominees, the genealogy was drawn. Blood samples were analyzed using autosomal STR and Y-STR markers by Yfiler ™ Plus and GlobalFiler ™ Express kits and were electrophoresed with ABI 3500 genetic analyzer. Since to prove the claimed relative relationship, the common father of the grandfatherchr('39')s child must be common, so the allelic inheritance between them was examined.

The results of the Y-STR indicated that the alleged uncle-nephew relationship was not ruled out. However, the results of autosomal STR markers indicated the status of Amelogenin Y-null in the profiles of all males in the pedigree. Comparison of the obtained genetic profiles showed that there was no inheritance of the obligatory paternal allele in the 4 loci D8S1179, D2S441, THO1 and D10S1248 between A and H, which definitely negated the existence of a father-son relationship between the two individuals; Hence, the alleged uncle-nephew and aunt-nephew relationship was rejected.

Autosomal STR markers should be used to examine complex relative relationships, and the use of Y-STR markers should be limited to genetic testing of male specimens in rape evidence, crime scenes, and non-paternity cases.