Application of ITO Method in Determination of Special Half-Sibling Relationship / 法医学杂志

OBJECTIVES@#To identify whether the relationship between Zhang A, Zhang B, Zhang C and Zhang X is the half-sibling relationship whose mother is sister (hereinafter referred to as the special half-sibling relationship) or the common first cousin relationship and discuss the application of ITO method in discriminating the special kinship.@*METHODS@#DNA was extracted from blood stain of four identified individuals, PowerPlex® 21 System and AGCU 21+1 STR kit were used to detect autosomal STR genetic markers. Investigator® Argus X-12 QS kit was used to detect the X chromosome STR genetic markers, the special half-sibling index (SHSI) and first cousin index (FCI) and their likelihood ratio (LR) were calculated by ITO method.@*RESULTS@#The LR results of SHSI to FCI, which were calculated based on autosomal STR genotyping and the analysis of X-STR genotyping results suggested that the relationship between Zhang A, Zhang B, Zhang C and Zhang X was inclined to be a special half-sibling relationship.@*CONCLUSIONS@#For the identification of special kinship, it is necessary to comprehensively apply various genetic markers according to the case. After the conclusion that shared alleles cannot be excluded from the analysis, ITO method can be further used to establish discriminant assumptions according to the specific case to obtain objective and reliable identification opinions.

Analysis and Countermeasure for Complex Cases in Adoption Paternity Testing / 中山大学学报(医学科学版)

[Objective] To explore how to deal with the paternity test of complex adoption cases. [Method] Samples from 13 families, in which adoptive parents were suspected related to biological parents, were genotyped using "Identifder + Sinofder + Powerplex 16" combined system (D8S1179, D21S11, D7S820, CSFIPO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818, FGA, D6S1043, D12S391, PentaD, PentaE) followed by further statistical analysis. [Result] Among all 13 cases, 2 were completely accordance with the Mendel law, PI > 10 000. There found more than 3 inconsistent loci in 8 cases. And found 1～2 inconsistent loci in 3 cases, needed to test more STR loci until PI≥10 000. The half sibling index (HSI) was also calculated with ITO method. The adoptive parents of 2 cases were not excluded from a full sibling with biological parents. In addition, Y-STR loci were tested for 4 cases (father/son). Two adoptive fathers of them were not excluded from the paternal relationship with biological fathers. [Conclusion] The most (76.9%) of all (13) complex adoptive cases of paternity test could be drawn a definite conclusion with combined system of "Identifder + Sinefiler + Powerplexl6". Minority (23.1%) of them was not definite yet and needed testing more STIR loci. Meanwhile, we suggested adding Y-STR tests and providing HSI for reference.