ABSTRACT
Objective To observe and analyze the mutation characteristics of 17 STR loci among the paternity test cases in Guangxi area .Methods Among 1 786 cases of non—exclusion parentage ,1 430 cases were parental triplet and 356 cases were uniparental diad ,1 001 persons were Han people ,2 102 persons were Zhuang people and 113 persons were other ethnic group in the parents .The genome DNA was extracted by Chelex-100 method .17 short tandem repeat (STR) loci were detected by Power Plex ? 18D System Kit .The paternity testing containing mutant STR loci were screened out from 1786 cases .The locus-specific ,specificity of paternal and maternal ,and allele-specific mutation rates were observed and analyzed ,respectively .The characteristics of the muta-tions were studied .Results In total ,75 mutations events were observed at 16 of the 17 loci .Among them ,73 (97 .34% ) times were one step mutation ,onece(1 .33% ) was two—step mutation ,and once(1 .33% ) was three—step mutation ,no mutation was found at the TPOX locus .The mutation rates ranged 0 .031 1% —0 .404 2% ,and the mean mutation rate was 0 .145 8% .The proportion of the paternal mutations and the maternal mutations was 5 .4:1 .0 ,the difference had statistical significance(P0 .05) .Conclusion STR loci mutation is common phenomenon in paternity test .The data of STR loci mutations should be constantly accumulated for selecting the genetic characteristics in line with the Guangxi population and the genetic markers of STR loci with high identification ability to ensure ac-curate and reliable identification results .
ABSTRACT
Objective Estimate the paternity exclusion probability for 15 short tandem repeats (CODIS set plus Penta D and Penta E) in duo paternity tests. Methods 644 random individuals were paired to con-struct 207046 fictitious duo families. Cases of non-exclusion or with only one exclusionarylocus were count-ed. Results 27 cases could not be excluded by the 15 STR loci. The combined probability of exclusion was 0.999869. Number of cases showing only one exclusionary locus was 384 (0.185%). Conclusion To con-firm relationship in duo cases with only 15 STRs should be careful. Extensive genetic markers is needed to discriminate one locus exclusion or mutation.
ABSTRACT
Objective To comparatively analyze the DNA extracted from sweat latent fingerprints on the adhesive side of tapes by three kinds of methods. Methods DNA was extracted from sweat latent fingerprint on the adhesive side of tapes using silicon bead test,QIA micro Kit and combined silicon bead-QIA micro Kit. STR loci were detected by multiplex PCR procedures. The PCR product was electrophoresed on an ABI 3100 Genetic Analyzer. Results 36%of the sweat latent fingerprints on the adhesive side of tapes was successfully genotyped using combined silicon bead-QIA micro Kit, and 21% using QIA micro Kit. Conclusion DNA genotyping of the sweat latent fingerprints on the adhesive side of tapes reveals higher possibility using combined silicon bead-QIA micro Kit than using QIA micro Kit and is less time-consuming.
ABSTRACT
Objective To investigate the extraction of DNA from urine and urine stains and typing.Methods DNA was extracted from urine and urine stains with Chelex-100 extraction method and QIAamp Mini Kit.STR loci were typed after amplification by PCR procedures with Profiler Plus Kit.Results STR loci could be well typed in DNA extracted from the urine,which was fresh or preserved properly for less than 12 hours.Satisfactory DNA typing could be made in 50% of the urine preserved for two days.No typing results were obtained in the samples kept for seven days or much longer time,and typing was rarely available using urine stains.Conclusion DNA extracted from the fresh urine can be typed,which may be used in forensic identification.