Background: This study aims to study MUT gene mutation spectrum in Chinese patients with isolated methylmalonic academia (MMA) and their clinical features for the potential genotype-phenotype correlation. Methods: For...Background: This study aims to study MUT gene mutation spectrum in Chinese patients with isolated methylmalonic academia (MMA) and their clinical features for the potential genotype-phenotype correlation. Methods: Forty-three patients were diagnosed with isolated MMA by elevated blood propionylcarnitine, propionylcarnitine to acetylcarnitine ratio, and urine methylmalonate without hyperhomocysteinemia. The MUT gene was amplifi ed by polymerase chain reaction and directly sequenced. Those patients with at least one variant allele were included. The novel missense mutations were assessed by bioinformatic analysis and screened against alleles sequenced from 50 control participants. Results: Among the 43 patients, 38 had typical clinical presentations, and the majority (30/38) experienced early-onset MMA. Eight patients died and seven were lost to follow-up. Twenty patients had poor outcomes and eight showed normal development. The 43 identified MUT gene mutations had at least one variant allele, whereas 35 had two mutant alleles. Of the 33 mutations reported before, eight recurrent mutations were identified in 32 patients, and c.729_730insTT (p.D244Lfs*39) was the most common (12/78) in the mutant alleles. Of the 10 novel mutations, six were missense mutations and four were premature termination codon mutations. The six novel missense mutations seemed to be pathogenic. Conclusions: A total of 10 novelMUT mutations were detected in the Chinese population. c.729_730insTT (p.D244Lfs*39) was the most frequent mutation. A genotype-phenotype correlation could not be found, but the genotypic characterization indicated the need of genetic counseling for MMA patients and early prenatal diagnoses for high-risk families.展开更多
Methylmalonic aciduria（MMA） is a common inherited autosomal recessive disorder resulting from defects in the enzyme methylmalonyl CoA mutase（MCM,mut complementation group） or in the synthesis of the MCM cofactor a...Methylmalonic aciduria（MMA） is a common inherited autosomal recessive disorder resulting from defects in the enzyme methylmalonyl CoA mutase（MCM,mut complementation group） or in the synthesis of the MCM cofactor adenosylcobalamin（cbl complementation groups）.The defects in the mut complementation group accounts for the largest number of patients with isolated MMA.At least 200 mutations in the MUT gene on chromosome 6p12 have been identified in MMA patients until now.This study aimed to investigate the clinical characteristics of MMA and genomic variations in the MUT gene of Chinese patients.Genomic DNA was extracted from 18 patients who were diagnosed as having isolated MMA by gas chromatography/mass spectrometry（GC-MS）,and from some of their parents as well.Amplification and direct sequencing of the MUT coding regions（exon 2-13） and their adjacent intronic consensus splice sites were performed in order to identify the disease causing mutations.In this group,six novel mutations in the MUT gene,c.424AG（p.T142A）,c.786TG（p.S262R）,c.808GC（p.G270R）,c.1323_1324insA,c.1445-1GA and c.1676＋77AC were identified.p.T142A and p.G270R were respectively detected at a heterozygous level in one patient.Two previously reported mutations,c.682CT（p.R228X） and c.323GA（p.R108H） were also found in this study.In addition,six previously described single nucleotide polymorphism（SNP）,c.636AG（p.K212K）,c.1495GA（p.A499T）,c.1595AG（p.H532R）,c.1992GA（p.A664A）,c.2011GA（p.V671I） and c.1677-53AG were identified.In this study,we updated the spectrum of MUT mutations and identified the main MMA-causing mutations in Chinese MMA patients.展开更多
AIM： To establish and validate the mutation testing for identification and characterization of hereditary non-polyposis colorectal cancer （HNPCC） in suspected Chinese patients. METHODS： Five independent Chinese ki...AIM： To establish and validate the mutation testing for identification and characterization of hereditary non-polyposis colorectal cancer （HNPCC） in suspected Chinese patients. METHODS： Five independent Chinese kindreds with HNPCC fulfilling the classical Amsterdam criteria were collected. Genomic DNA was extracted after informed consent was obtained. The coding region of hMSH2 and hMLH1 genes was detected by polymerase chain reaction （PCR） and denaturing high-performance liquid chromatography （DHPLC）. Mutations identified in the proband by DHPLC were directly sequenced using a 377 DNA sequencer, analyzed with a basic local alignment tool （BLAST）, and tested in the corresponding family members by direct DNA sequencing. RESULTS： Mutations were identified in two Chinese HNPCC kindreds. One was the missense mutation of hMSH2 c.1808A→G resulting in Asp 603 Gly identified in the proband of the fifth HNPCC （HNPCCS） kindred. In the HNP5 kindred, three family members were found to have this mutation and two of them had colorectal cancer. The other mutation of hMLH1 c.1882A→G was identified in the HNP2 kindred＇s proband, which might be the nonsense mutation analyzed by BLAST. CONCLUSION： Pedigree investigation and mutation testing of hMSH2 and hMLH1 are the practical methods to identify high-risk HNPCC patients in China.展开更多
蝎毒镇痛活性肽Bm K Ang M1是从东亚钳蝎(Buthus martensii Karsch)蝎毒中分离得到的一种新型长链蝎毒素,其镇痛活性强且毒性低,有望开发成镇痛新药。本文将Bm K Ang M1基因转入毕赤酵母(Pichia pastoris)GS115,筛选得到甲醇利用缓慢型(...蝎毒镇痛活性肽Bm K Ang M1是从东亚钳蝎(Buthus martensii Karsch)蝎毒中分离得到的一种新型长链蝎毒素,其镇痛活性强且毒性低,有望开发成镇痛新药。本文将Bm K Ang M1基因转入毕赤酵母(Pichia pastoris)GS115,筛选得到甲醇利用缓慢型(Muts)和快速型(Mut+)的重组子;采用实时荧光定量PCR方法,检测了Mut+重组子中Bm K Ang M1基因的拷贝数,筛选出含单拷贝Bm K Ang M1基因的Mut+重组子;在相同培养条件下,比较了含单拷贝Bm K Ang M1基因的Muts和Mut+重组子表达Bm K Ang M1的水平。结果表明,Muts重组子中Bm K Ang M1基因转录水平是Mut+重组子的2.7倍,Muts重组子中Bm K Ang M1蛋白表达量是Mut+重组子的1.5倍。因此,Muts重组子比Mut+重组子具有更强的Bm K Ang M1表达能力。展开更多
目的分析淋巴结转移性结直肠癌中DNA错配修复基因(mismatch repair,MMR)系统MLH1(Mut L homolog1)和MSH2(Mut S homolog 2)基因的表达水平及临床意义。方法选取2015年6月至2017年4月收治的120例淋巴结转移性结直肠癌患者为研究对象,同...目的分析淋巴结转移性结直肠癌中DNA错配修复基因(mismatch repair,MMR)系统MLH1(Mut L homolog1)和MSH2(Mut S homolog 2)基因的表达水平及临床意义。方法选取2015年6月至2017年4月收治的120例淋巴结转移性结直肠癌患者为研究对象,同期选取120例无淋巴结转移的结直肠癌患者为对照;通过免疫组化法、实时荧光定量PCR法(q RT-PCR)、Western blot法,分别检测两组正常癌旁组织及病灶组织中MLH1、MSH2蛋白阳性表达缺失率,MLH1、MSH2 m RNA及蛋白表达水平。结果两组患者病灶组织MLH1、MSH2蛋白阳性表达缺失率均高于癌旁组织,而MLH1、MSH2 m RNA及蛋白相对表达水平均低于癌旁组织,差异均有统计学意义(P均<0.05);淋巴结转移性结直肠癌组病灶组织MLH1、MSH2蛋白阳性表达缺失率均高于无淋巴结转移组,MLH1、MSH2 m RNA及蛋白相对表达水平均低于无淋巴结转移组,差异均有统计学意义(P均<0.05);两组癌旁组织MLH1、MSH2蛋白阳性表达缺失率、MLH1、MSH2 m RNA及蛋白相对表达水平比较差异均无统计学意义(P均>0.05);MLH1、MSH阳性表达缺失率与淋巴结转移性结直肠癌患者的肿瘤直径、浸润深度、分化程度及淋巴结转移数有密切关系(P均<0.01),而与年龄无关(P>0.05)。结论淋巴结转移性结直肠癌中MLH1、MSH2表达水平显著降低,推测其在结直肠癌由无淋巴结转移进展为发生淋巴结转移中具有重要作用。展开更多
基金supported by grants from the National Key Technology R&D Program(2012BAI09B04)the Special Basic Work of Science and Technology(2014FY110700).
文摘Background: This study aims to study MUT gene mutation spectrum in Chinese patients with isolated methylmalonic academia (MMA) and their clinical features for the potential genotype-phenotype correlation. Methods: Forty-three patients were diagnosed with isolated MMA by elevated blood propionylcarnitine, propionylcarnitine to acetylcarnitine ratio, and urine methylmalonate without hyperhomocysteinemia. The MUT gene was amplifi ed by polymerase chain reaction and directly sequenced. Those patients with at least one variant allele were included. The novel missense mutations were assessed by bioinformatic analysis and screened against alleles sequenced from 50 control participants. Results: Among the 43 patients, 38 had typical clinical presentations, and the majority (30/38) experienced early-onset MMA. Eight patients died and seven were lost to follow-up. Twenty patients had poor outcomes and eight showed normal development. The 43 identified MUT gene mutations had at least one variant allele, whereas 35 had two mutant alleles. Of the 33 mutations reported before, eight recurrent mutations were identified in 32 patients, and c.729_730insTT (p.D244Lfs*39) was the most common (12/78) in the mutant alleles. Of the 10 novel mutations, six were missense mutations and four were premature termination codon mutations. The six novel missense mutations seemed to be pathogenic. Conclusions: A total of 10 novelMUT mutations were detected in the Chinese population. c.729_730insTT (p.D244Lfs*39) was the most frequent mutation. A genotype-phenotype correlation could not be found, but the genotypic characterization indicated the need of genetic counseling for MMA patients and early prenatal diagnoses for high-risk families.
基金supported by grants from the National Basic Research Program of China(2005CB522507)the 11th Five-year Plan of National Science & Technology(2006BAI05A07)
文摘Methylmalonic aciduria（MMA） is a common inherited autosomal recessive disorder resulting from defects in the enzyme methylmalonyl CoA mutase（MCM,mut complementation group） or in the synthesis of the MCM cofactor adenosylcobalamin（cbl complementation groups）.The defects in the mut complementation group accounts for the largest number of patients with isolated MMA.At least 200 mutations in the MUT gene on chromosome 6p12 have been identified in MMA patients until now.This study aimed to investigate the clinical characteristics of MMA and genomic variations in the MUT gene of Chinese patients.Genomic DNA was extracted from 18 patients who were diagnosed as having isolated MMA by gas chromatography/mass spectrometry（GC-MS）,and from some of their parents as well.Amplification and direct sequencing of the MUT coding regions（exon 2-13） and their adjacent intronic consensus splice sites were performed in order to identify the disease causing mutations.In this group,six novel mutations in the MUT gene,c.424AG（p.T142A）,c.786TG（p.S262R）,c.808GC（p.G270R）,c.1323_1324insA,c.1445-1GA and c.1676＋77AC were identified.p.T142A and p.G270R were respectively detected at a heterozygous level in one patient.Two previously reported mutations,c.682CT（p.R228X） and c.323GA（p.R108H） were also found in this study.In addition,six previously described single nucleotide polymorphism（SNP）,c.636AG（p.K212K）,c.1495GA（p.A499T）,c.1595AG（p.H532R）,c.1992GA（p.A664A）,c.2011GA（p.V671I） and c.1677-53AG were identified.In this study,we updated the spectrum of MUT mutations and identified the main MMA-causing mutations in Chinese MMA patients.
基金The Special Funds of China Education Ministry for Returnees, No. 2003-14
文摘AIM： To establish and validate the mutation testing for identification and characterization of hereditary non-polyposis colorectal cancer （HNPCC） in suspected Chinese patients. METHODS： Five independent Chinese kindreds with HNPCC fulfilling the classical Amsterdam criteria were collected. Genomic DNA was extracted after informed consent was obtained. The coding region of hMSH2 and hMLH1 genes was detected by polymerase chain reaction （PCR） and denaturing high-performance liquid chromatography （DHPLC）. Mutations identified in the proband by DHPLC were directly sequenced using a 377 DNA sequencer, analyzed with a basic local alignment tool （BLAST）, and tested in the corresponding family members by direct DNA sequencing. RESULTS： Mutations were identified in two Chinese HNPCC kindreds. One was the missense mutation of hMSH2 c.1808A→G resulting in Asp 603 Gly identified in the proband of the fifth HNPCC （HNPCCS） kindred. In the HNP5 kindred, three family members were found to have this mutation and two of them had colorectal cancer. The other mutation of hMLH1 c.1882A→G was identified in the HNP2 kindred＇s proband, which might be the nonsense mutation analyzed by BLAST. CONCLUSION： Pedigree investigation and mutation testing of hMSH2 and hMLH1 are the practical methods to identify high-risk HNPCC patients in China.
文摘蝎毒镇痛活性肽Bm K Ang M1是从东亚钳蝎(Buthus martensii Karsch)蝎毒中分离得到的一种新型长链蝎毒素,其镇痛活性强且毒性低,有望开发成镇痛新药。本文将Bm K Ang M1基因转入毕赤酵母(Pichia pastoris)GS115,筛选得到甲醇利用缓慢型(Muts)和快速型(Mut+)的重组子;采用实时荧光定量PCR方法,检测了Mut+重组子中Bm K Ang M1基因的拷贝数,筛选出含单拷贝Bm K Ang M1基因的Mut+重组子;在相同培养条件下,比较了含单拷贝Bm K Ang M1基因的Muts和Mut+重组子表达Bm K Ang M1的水平。结果表明,Muts重组子中Bm K Ang M1基因转录水平是Mut+重组子的2.7倍,Muts重组子中Bm K Ang M1蛋白表达量是Mut+重组子的1.5倍。因此,Muts重组子比Mut+重组子具有更强的Bm K Ang M1表达能力。
文摘目的分析淋巴结转移性结直肠癌中DNA错配修复基因(mismatch repair,MMR)系统MLH1(Mut L homolog1)和MSH2(Mut S homolog 2)基因的表达水平及临床意义。方法选取2015年6月至2017年4月收治的120例淋巴结转移性结直肠癌患者为研究对象,同期选取120例无淋巴结转移的结直肠癌患者为对照;通过免疫组化法、实时荧光定量PCR法(q RT-PCR)、Western blot法,分别检测两组正常癌旁组织及病灶组织中MLH1、MSH2蛋白阳性表达缺失率,MLH1、MSH2 m RNA及蛋白表达水平。结果两组患者病灶组织MLH1、MSH2蛋白阳性表达缺失率均高于癌旁组织,而MLH1、MSH2 m RNA及蛋白相对表达水平均低于癌旁组织,差异均有统计学意义(P均<0.05);淋巴结转移性结直肠癌组病灶组织MLH1、MSH2蛋白阳性表达缺失率均高于无淋巴结转移组,MLH1、MSH2 m RNA及蛋白相对表达水平均低于无淋巴结转移组,差异均有统计学意义(P均<0.05);两组癌旁组织MLH1、MSH2蛋白阳性表达缺失率、MLH1、MSH2 m RNA及蛋白相对表达水平比较差异均无统计学意义(P均>0.05);MLH1、MSH阳性表达缺失率与淋巴结转移性结直肠癌患者的肿瘤直径、浸润深度、分化程度及淋巴结转移数有密切关系(P均<0.01),而与年龄无关(P>0.05)。结论淋巴结转移性结直肠癌中MLH1、MSH2表达水平显著降低,推测其在结直肠癌由无淋巴结转移进展为发生淋巴结转移中具有重要作用。
