Abstract: Objective Determination strategies for half sibling sharing a same mother were investigated through the detection of autosomal and X-chromosomal STR（X-STR） loci and polymorphisms on hypervariable（HV） region of mitochondrial DNA（mtDNA）. Methods Genomic DNA were extracted from blood stain samples of the 3 full siblings and one dubious half sibling sharing the same mother with them. Fifteen autosomal STR loci were genotyped by SinofilerTM kit, and 19 X-STR loci were genotyped by Mentype Argus X-8 kit and 16 plex in-house system. Polymorphisms of mtDNA HV-Ⅰ and HV-Ⅱ were also detected with sequencing technology. Results Full sibling relationship between the dubious half sibling and each of the 3 full siblings were excluded based on the results of autosomal STR genotyping and calculation of full sibling index（FSI） and half sibling index（HIS）. Results of sequencing for mtDNA HV-Ⅰ and HV-Ⅱ showed that all of the 4 samples came from a same maternal line. X-STR genotyping results determined that the dubious half sibling shared a same mother with the 3 full siblings. Conclusion It is reliable to combine three different genotyping technologies including autosomal STR, X-STR and sequencing of mtDNA HV-Ⅰ and HV-Ⅱ for determination of half sibling sharing a same mother.

Key words: forensic genetics, genetic markers, DNA, mitochondrial, X-STR, half sibling