Profiling the repertoire of T-cell receptor beta-chain variable genes in peripheral blood lymphocytes from subjects who have recovered from acute hepatitis B virus infection

The profile of T-cell receptor beta-chain variable （TRBV） genes usually skews in subjects with virus infection or cancer. The gene melting spectral pattern （GMSP） can be used to determine the profile of the TRBV gene family. To explore the portrait of the TRBV family in peripheral blood lymphocytes from subjects who have recovered from acute hepatitis B virus infection （AHI）, peripheral blood mononuclear cells （PBMCs） were separated and further sorted into CD4^＋ and CD8^＋ T-cell subsets. The molecular features of the TRBV complementary determining region 3 （CDR3） motifs were determined using GMSP analysis. When a GMSP profile showed a single peak, the monoclonally expanded TRBV gene was cloned and sequenced. Skewed expansions of multiple TRBV genes were observed among the CD4^＋ and CD8^＋ T-cell subsets and the PBMCs. The frequency of monoclonally expanded TRBV genes in the CD8^＋ T-cell subset was significantly higher than that of the CD4^＋ T-cell subset and the PBMCs. Compared to other members of the TRBV gene family, TRBV11, BV15 and BV20 were predominantly expressed in the repertoire of peripheral blood lymphocytes in recovered AHI subjects. The relatively conserved amino acid motifs of TRBV5.1 and BV20 CDR3 were also detected in the CD4^＋ and CD8^＋ T-cell subsets. These results demonstrate the presence of multiple biased TRBV families in recovered AHI subjects. TRBV11, BV15 and BV20, especially from the CD8＋ T-cell subset, may be relevant to the pathogenesis of subjects with AHh The preferentially selected TRBV5.1 and BV20 with the relatively conserved CDR3 motif may be potential targets for personalized treatments of chronic HBV infection.     

Analysis of clinical phenotype and ACAT1 gene mutation in a family affected with β-ketothiolase deficiency北大核心CSCD

Objective: To investigate the clinical phenotype and ACATI gene mutation in a family affected with β-ketothiolase deficiency (BKTD). Methods: Clinical features and laboratory test data were collected. The probands were monozygotic twin brothers. Genomic DNA was isolated from peripheral blood leukocytes obtained from the probands and their family members. Molecular genetic testing of the ACAT1 gene was carried out. Results: The probands have presented with fever, vomiting and severe ketoacidosis. By arterial blood gas testing, pH was determined to be 7. 164, bicarbonate was 4. 0 mmol/L, and urine ketone was + + + +. Urinary organic acid gas chromatography-mass spectrometry analysis showed excessive excretion of 3-hydroxybutyric acid, 2-methyl-3-hydroxybutyric acid and tiglylglycine. Increased 3-hydroxybutyrylcarnitine (C4-OH), tiglylcarnitine (C5:1) and 3-hydroxyisovalerylcarnitine (C5-0H) levels. The clinical phenotype of proband's parents were both normal, but an elder sister turned out to be an affected patient. Genetic analysis has identified two heterozygous mutations [c. 622C>T(p. R208X) and c. 653C>T(p. S218F)] in the proband, which were respectively detected in the mother and father. The c. 653C>T(p. S218F) mutation was not found among the 100 healthy controls and has not been included in the Human Gene Mutation Database (HGMD). Conclusion: The primary clinical manifestations of BKTD is ketoacidosis. Urine organic acid and blood acylcarnitine analyses play an important role in the diagnosis of the disease. The compound heterozygous of ACAT1 gene mutations probably underlie the BKTD in our patient. © 2016, West China University of Medical Sciences. All rights reserved.     

Rapid Identification of Pathogenic Bacteria by means of Two Conservative Gene Loci＇ Specific PCR-CE-RFLP

To establish a rapid identification method for common pathogenic bacteria on the basis of molecular biology and to construct a preliminary Polymerase Chain Reaction-Capillary Electrophoresis-Restriction Fragment Length Polymorphism (PCR-CE-RFLP) database of bacteria isolated from clinical specimens frequently, 183 strains collected from clinical samples belonging to 12 genera and 19 species whose biochemical characterizations corresponded to the typical ones were examined.The genomic DNAs were amplified by two pairs of fluorescence labeled primers aiming at 16S rRNA gene and 16S-23S rRNA spacer region gene respectively at the same time. PCR products were then digested by restriction endonuclease Hae Ⅲ in-completely before taking capillary electrophoresis. The results with the PCR-CE-RFLP patterns of 16S rRNA genes were just alike within some genera, but when it comes to 16S-23S rRNA spacer region genes, each bacterium showed a unique pattern, which can be distinguished from each other easily. It seems that PCR-CE-RFLP patterns of 16S rRNA gene could only be used to classify the bacteria into family level, whereas the data of 16S-23S rRNA spacer region gene could be utilized to identify the whole microorganisms as precisely as the species level. In spite of the data of the spacer region gene alone can be sufficiently to verify the whole bacteria, we insist that the 16S rRNA gene could be of some assistant in case that there should be lots of families of bacteria, in which some similar ones, with the same RFLP data of 16S-23S rRNA spacer region gene, may coexist. This study proves that the utility of PCR-CE-RFLP is a convenient, rapid method to identify pathogenic bacteria, and is also a quick diagnosis measure for application to clinical use.     

中国Rett综合征患儿突变基因的亲源分析

Objective To identify the parental origin of methyl-CpG-binding protein 2 (MECP2)gene mutations in Chinese patients with Rett syndrome. Methods Single nucleotide polymorphisms (SNPs) in intron 3 of the MECP2 gene were analyzed by PCR and sequencing in 115 patients with Rett syndrome.Then sequencing of the SNP region was performed for the fathers of the patients who had at least one SNP,to determine which allele was from the father. Then allele-specific PCR was performed and the products were sequenced to see whether the allele from father or mother harbored the mutation. Results Seventy-six of the 115 patients had at least one SNP. Three hot SNPs were found in these patients. They were: IVS3+22C＞G, IVS3+266C＞T and IVS3+683C＞T. Among the 76 cases, 73 had a paternal origin of MECP2 mutations, and the other 3 had a maternal origin. There were multiple types of MECP2 mutation of the paternal origin, including 4 frame shift, 2 deletion and 67 point (56 C＞T, 6 C＞G, 2 A＞G, 2 G＞T and 1 A＞T) mutations. The mutation types of the 3 ptients with maternal origin included 2 frame shift and 1 point (C＞T) mutation. Conclusion In Chinese RTT patients, the MECP2 mutations are mostly of paternal origin.     

中国Rett综合征患儿突变基因的亲源分析

Objective To identify the parental origin of methyl-CpG-binding protein 2 (MECP2)gene mutations in Chinese patients with Rett syndrome. Methods Single nucleotide polymorphisms (SNPs) in intron 3 of the MECP2 gene were analyzed by PCR and sequencing in 115 patients with Rett syndrome.Then sequencing of the SNP region was performed for the fathers of the patients who had at least one SNP,to determine which allele was from the father. Then allele-specific PCR was performed and the products were sequenced to see whether the allele from father or mother harbored the mutation. Results Seventy-six of the 115 patients had at least one SNP. Three hot SNPs were found in these patients. They were: IVS3+22C＞G, IVS3+266C＞T and IVS3+683C＞T. Among the 76 cases, 73 had a paternal origin of MECP2 mutations, and the other 3 had a maternal origin. There were multiple types of MECP2 mutation of the paternal origin, including 4 frame shift, 2 deletion and 67 point (56 C＞T, 6 C＞G, 2 A＞G, 2 G＞T and 1 A＞T) mutations. The mutation types of the 3 ptients with maternal origin included 2 frame shift and 1 point (C＞T) mutation. Conclusion In Chinese RTT patients, the MECP2 mutations are mostly of paternal origin.     

两个新RUNX2基因突变引起家族性锁骨颅骨发育不全

Objective To identify the RUNX2 gene mutation in two unrelated Chinese families with cleidocranial dysplasia (CCD), and to assess the feasibility of gene diagnosis for patients with CCD. Methods Genomic DNA was isolated from peripheral blood samples of 4 patients and 4 healthy members in the two pedigrees as well as 102 unrelated healthy controls. All 7 coding exons and their flanking intronic sequences of the RUNX2 gene were amplified by PCR, then the PCR products were sequenced bi-directionally. The sequencing results were compared with normal sequences in GenBank to identify the mutation. The mutation was confirmed by RFLP with restriction endonuclease. Results In one family, a novel heterozygous missense mutation c. 346T＞A (W116R) in exon 1 of the RUNX2 gene was detected in the two affected individuals, and the mutation was further confirmed with Bsr Ⅰ restriction endonuclease digestion. In the other family, a novel nonsense mutation c. 610A＞T (K204X) was identified in the two patients. No above sequence change was found in the 102 healthy controls. Conclusion Two novel RUNX2 mutations were found in two unrelated Chinese families with cleidoeranial dysplasia. The identification of these mutations further extended the mutation spectrum of RUNX2 gene and will facilitate prenatal diagnosis and gene diagnosis of CCD.     

Analysis of TGFBI gene mutation in a Chinese family with atypical Reis-Bückler corneal dystrophy

Objective To identify the TGFBI gene mutation and the relationship between genotype and phenotype of a Chinese family with atypical Reis-Bückler corneal dystrophy (RBCD). Methods Four patients, two non-carrier relatives of the family were enrolled in the present study. In addition to ophthalmologic examinations, PCR amplification and DNA sequencing of exons 4, 11, 12, and 14 of the TGFBI gene were carried out. Exon 14 was also sequenced in 100 healthy controls. Results A G to A transition at eodon 623 in all affected members was identified. This mutation resulted in a substitution of glyeine (GGC) to aspartic acid (GAC) at the protein level. None of the healthy family members, or any of the 100 control subjects carried this mutation. Conclusion The G623D mutation of the TGFBI gene caused an atypical Reis-Buckler corneal dystrophy in this family. This mutation is reported in Chinese for the first time.     

Analysis of TGFBI gene mutation in a Chinese family with atypical Reis-Bückler corneal dystrophy

Objective To identify the TGFBI gene mutation and the relationship between genotype and phenotype of a Chinese family with atypical Reis-Bückler corneal dystrophy (RBCD). Methods Four patients, two non-carrier relatives of the family were enrolled in the present study. In addition to ophthalmologic examinations, PCR amplification and DNA sequencing of exons 4, 11, 12, and 14 of the TGFBI gene were carried out. Exon 14 was also sequenced in 100 healthy controls. Results A G to A transition at eodon 623 in all affected members was identified. This mutation resulted in a substitution of glyeine (GGC) to aspartic acid (GAC) at the protein level. None of the healthy family members, or any of the 100 control subjects carried this mutation. Conclusion The G623D mutation of the TGFBI gene caused an atypical Reis-Buckler corneal dystrophy in this family. This mutation is reported in Chinese for the first time.     

Analysis of TGFBI gene mutation in a Chinese family with atypical Reis-Bückler corneal dystrophy

Objective To identify the TGFBI gene mutation and the relationship between genotype and phenotype of a Chinese family with atypical Reis-Bückler corneal dystrophy (RBCD). Methods Four patients, two non-carrier relatives of the family were enrolled in the present study. In addition to ophthalmologic examinations, PCR amplification and DNA sequencing of exons 4, 11, 12, and 14 of the TGFBI gene were carried out. Exon 14 was also sequenced in 100 healthy controls. Results A G to A transition at eodon 623 in all affected members was identified. This mutation resulted in a substitution of glyeine (GGC) to aspartic acid (GAC) at the protein level. None of the healthy family members, or any of the 100 control subjects carried this mutation. Conclusion The G623D mutation of the TGFBI gene caused an atypical Reis-Buckler corneal dystrophy in this family. This mutation is reported in Chinese for the first time.