Mutation analysis of autosomal and X chromosomal STR in gynecologic and breast cancer / 中国法医学杂志

Objective To explore the mutation types and disciplines of STR commonly used in forensic in gynecologic and breast cancerand investigate the application of microdissection in forensic practice involving tumor tissue. Methods DNA of tumor tissues, adjacent normal tissues and peripheral blood from 62 patients with breast cancer, 62 patients with gynecologic cancer and 10 patients with benign gynecologic tumor were amplified by PowerPlex 21 System kit and Argus X-12 kit. Capillary electrophoresis of PCR products was carried out on an ABI 3130 Genetic Analyzer to obtain genotypes. Some tumor tissues with STR variation were microdissected. Results The genotype of peripheral blood in cancer patient was consistent with that of corresponding normal tissue. 4 types of STR variations were found in 46.77% gynecologic cancer tissues, compared with that in benign tumor tissues and breast cancer, the difference of STR variation was significant(P<0.01,P=0.009). The genotype of stromal cells separated by microdissection was consistent with that of corresponding adjacent normal tissue. Conclusion The STR loci detected in the study with poor stability are not suitable for forensic cases involving gynecologic cancer tissues. The genotype of stromal cells separated accurately from tumor tissues by microdissection could represent the normal DNA genotype of the individual with cancer. Microdissection is an effective solution in forensic cases with tumor tissues.

Exclusion of 15 Short Tandem Repeat Markers in Duo Paternity Testing / 中国法医学杂志

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.

Non-amplification of an Allele of D8S1179 Locus Due to Point Mutation in Flanking Region / 대한법의학회지

AmpFlSTR Profiler PlusTM PCR amplification system is highly efficient commercial DNA profiling system that are used by many institute for forensic individual identification. During the population study of 128 true Korean families (626 persons) with 9 loci of AmpFlSTR Profiler PlusTM PCR amplification system, we found unusual homozygous genotype at the D8S1179 locus in 4 families that is hard to explain with the Mendel's hereditary principles. The genotyping results suggest possibility of presence of non-amplified alleles due to deletion of one allele or polymorphism of primer-binding site. So we designed a new pair of primers of D8S1179 locus from GenBank data (GenBank Accession No. G08710). The newly designed primers amplified alleles that are not amplified with AmpFlSTR Profiler PlusTM PCR amplification system and all homozygous genotypes are typed to heterozygous genotype. We sequenced alleles of family members who have non-amplified alleles and we found G to A transition at the position of 147th base of GenBank sequence.