ELA ZAIMI, MERITA XHETANI, ELIDION RUSTO
Abstract
DNA forensic investigations can sometimes produce unexpected results, even in seemingly straightforward cases. One such case involved a paternity test where an alleged father sought confirmation of his biological relationship with a young girl. After two prior examinations produced contradictory results, the test was repeated at the DNA Laboratory of the Institute of Scientific Police in Tirana. Samples included three buccal swabs from the alleged father, one from the mother, and one from the child. Sixteen autosomal STR loci and AMELO were analyzed using PCR, followed by capillary electrophoresis on a Genetic Analyzer 3500 HID. The alleged father’s samples revealed a mixed DNA profile: three loci with three alleles, three loci with four alleles, and ten loci with two alleles. His medical history disclosed a prior bone marrow transplant, which explained the chimeric DNA pattern. This represents the first documented case of chimerism affecting DNA-based paternity testing in Albania. The case highlights how chimerism can lead to false exclusions in parentage testing and complicate genetic investigations. Awareness of medical history and expert consultation are essential to reduce misinterpretation and ensure reliable conclusions in such cases.
Key words: forensic genetics, chimera, DNA paternity testing, STR profile.