Polymorphism of five short tandem repeat systems in Chinese Han population in Chengdu / 法医学杂志

OBJECTIVE@#To obtain population genetic data of loci D11S4951, D11S4957, GATA193H05, D2S2951, and D6S2421 in Han population in Chengdu area and to validate the value of their forensic application.@*METHODS@#Blood samples were collected in EDTA tubes from unrelated individuals. DNAs were extracted with Chelex-100 and were analyzed by PCR and horizontal PAGE followed by silver staining.@*RESULTS@#Alleles 7, 10, 8, 6 and 8 were found in 5 STR loci, respectively. No deviations from Hardy-Weinberg balance were observed. The heterozygosities observed were 0.743, 0.772, 0.833, 0.650 and 0.800, respectively. The chances of exclusion were 0.497, 0.549, 0.662, 0.356 and 0.599, and the discrimination powers were 0.863, 0.912, 0.947, 0.829 and 0.931.@*CONCLUSION@#All of the five loci studied may be useful markers for individual identification and paternity testing.

Further study on heterogeneic basis of complement C8 beta deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>In Caucasian population, the most common molecular basis for C8 beta deficiency s a single C to T transition in exon 9 of C8 beta gene resulting in a stop codon. In previous family studies, two individuals were identified with C8 beta complete deficiency and were found to be only heterozygous for this mutation. This study was conducted by the present authors in search of other possible causes for these two C8 beta deficient individuals.</p><p><b>METHODS</b>Using direct DNA sequence analysis of all exon-specific PCR products of the C8 beta gene from these two C8 beta deficient patients and their descendants.</p><p><b>RESULTS</b>Two other C to T transitions at base 298 and 388 in exon 3 were detected, which could also create a termination codon. The descendants from one of the deficient patients were also analysed for the mutations, and it could be demonstrated that the two C to T mutations in exons 9 and 3 are segregating independently.</p><p><b>CONCLUSION</b>These two mutations, which create a termination codon, are sufficient to explain the complete C8 beta deficiency in both patients.</p>

Analysis of p53 gene mutation in esophageal exfoliative cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the feasibility of detecting p53 gene mutation in exfoliative esophageal cells, and compare gene mutation between precancerous lesions and normal esophageal exfoliative cells and correlate p53 gene mutation with esophageal carcinogenesis.</p><p><b>METHODS</b>Forty-eight samples (24 normal squamous epithelia and 24 severe squamous dysplasia) were obtained by balloon cytologic technique from a high incidence area, Yanting county, Sichuan Province, China in 1982. p53 gene mutations in exons 5 and 7 were analyzed by PCR-SSCP.</p><p><b>RESULTS</b>p53 genes were detected in all samples. Five samples with p53 mutation were detected in exon 7 and no mutation was detected in exon 5 in 24 severe dysplasia samples. Three of the 5 samples with mutation in exon 7 developed esophageal cancer in 1992, 1994 and 1996 respectively. No p53 gene mutation was detected in exon 5 and 7 in normal exfoliative samples.</p><p><b>CONCLUSION</b>p53 mutation may have occurred in the precancerous lesions which contributes in the initiation of human esophageal carcinogenesis.</p>

A study of genetic polymorphism of the STR locus D2S441 in Chinese Han population in Chengdu / 法医学杂志

Using PCR and PAG, followed by silver staining, the tetrameric STR D2S441 locus was studied in 260 unrelated Chinese individuals living in Chengdu. 9 alleles and 26 genotypes were observed. The range of fragment size was 131 bp to 155 bp. The genotype distribution of D2S441 locus in Han population was in accordance with Hardy-Weinberg equilibrium. Family survey confirmed Mendelian inheritance of alleles. The discriminating power (Dp), observed heterozygosity (H), polymorphism information content (PIC) and power of exclusion (PE) were 0.9084, 0.7885, 0.7390 and 0.5778 respectively. The results demonstrated that this locus was highly polymorphic and could be used for forensic identification and paternity testing.

Study on the construction of standard D1S549 allelic ladder via molecular cloning and its genetic polymorphism in Chinese three populations / 法医学杂志

OBJECTIVE@#To resolve the problem of the accuracy and standardization of STR-PCR typing in forensic practice, we have designed a new method to produce standard D1S549 allelic ladder.@*METHODS@#Eight different PCR amplified D1S549 allelic fragments were isolated from the gel, eluted into the distilled water and re-amplified by PCR. The purified allelic fragments were then blunt-end subcloned individually into the pUC plasmid vectors and transfected into competent E. coli DH5 alpha cells.@*RESULTS@#The sequencing results confirmed that the size and the construe of the inserts were correct. The recombinant plasmids DNA with 8 inserts were then used as templates for re-amplification to generate D1S549 standard ladder, with which the genetic polymorphisms of D1S549 locus in Chinese Han population in chengdu, Hui population in Gansu and Wei population in Xinjiang were studied.@*CONCLUSION@#The results showed that the standard ladder made via this method is excellent, and D1S549 locus is robust for genetic research and forensic application.