Investigation of the risk of false paternity result in determining paternity without mother in close consanguineous marriage

Due to various reasons such as economic concerns, the desire to reach results easily, fast, and cheaply along with the inability to reach the mother, paternity results have been given using the STR DNA profiles of the father and the child, without the STR DNA profile of the mother. It has been suggested that giving paternity results with only the STR DNA profiles of the father and the child, without the maternal STR DNA profile, with the kits with loci 17 and lower may cause false father detection. This study was planned with the hypothesis that the risk of giving false father acceptance result may pose a threat in cases of close consanguineous marriages, that are quite common in our society, and in incest cases that can be encountered in every society and are mostly kept secret. Intraoral swab samples (Power Plex Fusion 6C kit (23 autosomal STRs) were taken from a total of 89 volunteers from 15 families who had close consanguineous marriages (such as uncle, aunt, first cousins) and 101 male volunteers in the control group who had no consanguinity with these families). 3 Y-STR and Amelogenin) PCR and CE procedures were performed on these samples with the 27-site kit, and electropherograms were obtained. Comparisons were made by entering the data into an excel-based computer program. Paternity index and percentage of paternal acceptance were calculated without maternal DNA profile using the father and child Bayes theorem. The same procedure was performed also in the presence of maternal DNA profile. The DNA profile of each child was compared with the DNA profiles of the closely related father (uncle, grandfather and brother) candidates without the mother's DNA profile. The same procedure was also performed in the presence of maternal DNA profile. All these procedures (Power Plex Fusion 6C kit (including 23 autosomal STR, 3 Y-STR and Amelogenin)) were repeated by marking the loci of the ESS, ID Plus kits and CODIS system existing in the 27-site kit. All results were analyzed as full agreement, 1 locus mismatch, 2 loci mismatch, and 3 loci mismatch. The results revealed that the risk in marriages between close relatives, without the mother's DNA profile, poses a serious threat. It is necessary to take precautions in societies where close consanguineous marriages are common or in societies that migrate from such regions.