AIM: To determine whether HBV with the same characteristics causes dissimilar mutations in different hosts. METHODS: Full-length HBV genome was amplified and linked with pMD T18 vector. Positive clones were selected b...AIM: To determine whether HBV with the same characteristics causes dissimilar mutations in different hosts. METHODS: Full-length HBV genome was amplified and linked with pMD T18 vector. Positive clones were selected by double-restriction endonuclease digestion (EcoRⅠ and HindⅢ) and PCR. Twenty seven clones were randomly selected from an asymptomatic mother [at two time points: 602 (1 d) and 6022 (6 mo)] and her son [602 (S)], and the phylogenetic and mutational analysis was performed using BioEditor, Clustal X and MEGA software. Potential immune epitopes were determined by the Stabilized Matrix Method (SMM), SMM-Align Method and Emini Surface Accessibility Prediction. RESULTS: All of the 27 sequences were genotype C, the divergence between the mother and son was 0%-0.8%. Compared with another 50 complete sequences of genotype C, the mother and her son each had 13 specific nucleotides that differed from the other genotype C isolates. AA 1-11 deletion in preS1 was the dominant mutation in the mother (14/18). The 1762T/1764A double mutation existed in all clones of the mother, 3 of them were also coupled with G1896A mutation, but none were found in the son.17 bp deletion starting at nucleotide 2330 was the major mutation (5/9) in the son, which caused seven potential HLA class Ⅰ epitopes and one B cell epitope deletion, and produced a presumptive new start codon, downstream from the original one of the P gene. CONCLUSION: The HBV strain in the son came from his mother, and discrepant mutation occurred in the mother and her son during infection.展开更多
AIM： To investigate the genetic relationship between Hirschsprung＇s disease （HD） and intestinal neuronal dysplasia （IND） in Chinese population.METHODS： Peripheral blood samples were obtained from 30 HD patients...AIM： To investigate the genetic relationship between Hirschsprung＇s disease （HD） and intestinal neuronal dysplasia （IND） in Chinese population.METHODS： Peripheral blood samples were obtained from 30 HD patients, 20 IND patients, 18 HD/IND combined patients and 20 normal individuals as control. Genomic DNA was extracted according to standard procedure. Exons 11,13,15,i7 of RET proto-oncogene were amplified by polymerase chain reaction （PCR）. The mutations of RET proto-oncogene were analyzed by single strand conformational polymorphism （SSCP） and sequencing of the positive amplified products was performed.RESULTS： Eight germline sequence variants were detected. In HD patients, 2 missense mutations in exon 11 at nucleotide 15165 G→A （G667S）, 2 frameshifc mutations in exon 13 at nucleotide 18974 （18974insG）, 1 missense mutation in exon 13 at nucleotide 18919 A→G （K756E） and 1 silent mutation in exon 15 at nucleotide 20692 G→A（Q916Q） were detected. In HD/IND combined patients, 1 missense mutation in exon 11 at nucleotide 15165 G→A and 1 silent mutation in exon 13 at nucleotide 18888 T→G （L745L） were detected. No mutation was found in IND patients and controls.CONCLUSION： Mutation of RET proto-oncogene is involved in the etiopathogenesis of HD. The frequency of REr proto-oncogene mutation is quite different between IND and HD in Chinese population, IND is a distinct clinical entity genetically different from HD.展开更多
基金The Natural Science Foundation of Yunnan Province, No.200300172Hospital Science Foundation of The First People’s Hospital of Yunnan Province (2004)
文摘AIM: To determine whether HBV with the same characteristics causes dissimilar mutations in different hosts. METHODS: Full-length HBV genome was amplified and linked with pMD T18 vector. Positive clones were selected by double-restriction endonuclease digestion (EcoRⅠ and HindⅢ) and PCR. Twenty seven clones were randomly selected from an asymptomatic mother [at two time points: 602 (1 d) and 6022 (6 mo)] and her son [602 (S)], and the phylogenetic and mutational analysis was performed using BioEditor, Clustal X and MEGA software. Potential immune epitopes were determined by the Stabilized Matrix Method (SMM), SMM-Align Method and Emini Surface Accessibility Prediction. RESULTS: All of the 27 sequences were genotype C, the divergence between the mother and son was 0%-0.8%. Compared with another 50 complete sequences of genotype C, the mother and her son each had 13 specific nucleotides that differed from the other genotype C isolates. AA 1-11 deletion in preS1 was the dominant mutation in the mother (14/18). The 1762T/1764A double mutation existed in all clones of the mother, 3 of them were also coupled with G1896A mutation, but none were found in the son.17 bp deletion starting at nucleotide 2330 was the major mutation (5/9) in the son, which caused seven potential HLA class Ⅰ epitopes and one B cell epitope deletion, and produced a presumptive new start codon, downstream from the original one of the P gene. CONCLUSION: The HBV strain in the son came from his mother, and discrepant mutation occurred in the mother and her son during infection.
文摘AIM： To investigate the genetic relationship between Hirschsprung＇s disease （HD） and intestinal neuronal dysplasia （IND） in Chinese population.METHODS： Peripheral blood samples were obtained from 30 HD patients, 20 IND patients, 18 HD/IND combined patients and 20 normal individuals as control. Genomic DNA was extracted according to standard procedure. Exons 11,13,15,i7 of RET proto-oncogene were amplified by polymerase chain reaction （PCR）. The mutations of RET proto-oncogene were analyzed by single strand conformational polymorphism （SSCP） and sequencing of the positive amplified products was performed.RESULTS： Eight germline sequence variants were detected. In HD patients, 2 missense mutations in exon 11 at nucleotide 15165 G→A （G667S）, 2 frameshifc mutations in exon 13 at nucleotide 18974 （18974insG）, 1 missense mutation in exon 13 at nucleotide 18919 A→G （K756E） and 1 silent mutation in exon 15 at nucleotide 20692 G→A（Q916Q） were detected. In HD/IND combined patients, 1 missense mutation in exon 11 at nucleotide 15165 G→A and 1 silent mutation in exon 13 at nucleotide 18888 T→G （L745L） were detected. No mutation was found in IND patients and controls.CONCLUSION： Mutation of RET proto-oncogene is involved in the etiopathogenesis of HD. The frequency of REr proto-oncogene mutation is quite different between IND and HD in Chinese population, IND is a distinct clinical entity genetically different from HD.
