Mutation screening of the F Ⅷ gene in 10 hemophilia A families

Objective To identify the F Ⅷ gene mutations of patients and suspected female carriers in 10 Hemophilia A (HA) families, and to guide the prenatal diagnosis. Methods PCR, denaturing high performance liquid chromatogramphy(DHPLC) and DNA sequencing technologies were applied to screen the FⅧ gene of 8 HA patients and 12 suspected female carriers in the 10 families. Linkage analysis was performed by using St 14 (DXS 52), intron 13 (CA)n and EX18/Bcl Ⅰ of the FⅧ gene in the HA families.In prenatal diagnosis, we screened the same mutation found in the patients. PCR-restriction fragment length polymorphism was applied to detect the new missense mutations of F Ⅷ gene in 100 unrelated healthy individuals to exclude the possibility of polymorphism. Results (1) Five missense mutations, 3 frameshift mutations, 2 nonsense mutations and 2 single nucleotide polymorphism(SNP) were identified in 10 the HA families. Among them, c. 878A＞G, c. 1015A＞G, c. 6870G＞T, c. 1282delA, c. 3072_3073insT, c. 4880_4881insA and c. 5000G＞A were novel mutations or polymorphism. No missense mutations c. 878A＞G, c.1015A＞G and c. 6870G＞T, were found in the 100 healthy unrelated controls. (2) Nine suspected female carriers were confirmed at the gene level. (3) X risk chromosome could be determined in 4 HA families by genetic linkage analysis. (4) Among the four fetuses for prenatal diagnosis, 2 were normal, 1 was carrier and the remaining 1 was a patient. Conclusion Six novel mutations, i. e. , c. 878A＞G, c. 1015A＞G, c.6870G＞T, c. 1282delA, c. 3072_3073insT and c. 4880_4881insA, were identified in this study. PCR,DHPLC and DNA sequencing could be used to screen the gene mutations of HA patients, to carry out carrier detection and prenatal diagnosis of HA families efficiently, by combining with restriction endonuclease analysis and genetic linkage analysis.     

10个甲型血友病家系FⅧ基因突变分析

目的 分析10个家系中甲型血友病(hemophilia A,HA)患者及女性疑似携带者FⅧ基因突变,并指导产前诊断.方法 应用聚合酶链反应(polymerase chin reaction,PCR)、变性高效液相色谱技术(denaturing high performance liquid chromatogramphy,DHPLC)和DNA测序技术对10个家系中8例HA患者、12名女性疑似携带者的FⅧ基因进行突变检测,并应用St14(DXS 52)、13(CA)n、EX18/BclⅠ3个遗传标记位点对HA家系进行连锁分析.产前诊断检测已知突变位点.针对未见报道的新突变,用限制性内切酶进行分析,同时与100名表型正常的无关个体进行比较,排除多态性.结果 (1)在10个家系中发现5例错义突变、3例移码突变、2例无义突变和2个单核苷酸多态性(single nucleotide polymorphism,SNP)位点.错义突变c.878A＞G、c.1015A＞G和c.6870G＞T,移码突变c.1282delA、c3072_3073insT和c.4880_4881insA以及SNP位点c.5000 G＞A均为国际血友病网站和人类突变数据库未记载的突变或多态.在100名正常人中未检测到错义突变c.878A＞G、c.1015A＞G和c.6870G＞T.(2)在12名女性疑似携带者中,基困水平确诊9例为HA携带者,3名为正常人.(3)遗传连锁分析为4个家系提供了X风险染色体的有效信息.(4)产前诊断结果显示2例胎儿正常、1例HA携带者和1例HA患者.结论 发现c.878 A＞G、c.1015A＞G、c.6870G＞T、c.1282delA、c.3072 3073insT及c.4880_4881insA共6种能引起甲型血友病的新突变;PCR、DHPLC和DNA测序技术可有效检测甲型血友病患者基因突变,而联合限制性内切酶分析和遗传连锁分析能快速筛查HA携带者,进行有效的产前诊断.

Abstract：

Objective To identify the F Ⅷ gene mutations of patients and suspected female carriers in 10 Hemophilia A (HA) families, and to guide the prenatal diagnosis. Methods PCR, denaturing high performance liquid chromatogramphy(DHPLC) and DNA sequencing technologies were applied to screen the FⅧ gene of 8 HA patients and 12 suspected female carriers in the 10 families. Linkage analysis was performed by using St 14 (DXS 52), intron 13 (CA)n and EX18/Bcl Ⅰ of the FⅧ gene in the HA families.In prenatal diagnosis, we screened the same mutation found in the patients. PCR-restriction fragment length polymorphism was applied to detect the new missense mutations of F Ⅷ gene in 100 unrelated healthy individuals to exclude the possibility of polymorphism. Results (1) Five missense mutations, 3 frameshift mutations, 2 nonsense mutations and 2 single nucleotide polymorphism(SNP) were identified in 10 the HA families. Among them, c. 878A＞G, c. 1015A＞G, c. 6870G＞T, c. 1282delA, c. 3072_3073insT, c. 4880_4881insA and c. 5000G＞A were novel mutations or polymorphism. No missense mutations c. 878A＞G, c.1015A＞G and c. 6870G＞T, were found in the 100 healthy unrelated controls. (2) Nine suspected female carriers were confirmed at the gene level. (3) X risk chromosome could be determined in 4 HA families by genetic linkage analysis. (4) Among the four fetuses for prenatal diagnosis, 2 were normal, 1 was carrier and the remaining 1 was a patient. Conclusion Six novel mutations, i. e. , c. 878A＞G, c. 1015A＞G, c.6870G＞T, c. 1282delA, c. 3072_3073insT and c. 4880_4881insA, were identified in this study. PCR,DHPLC and DNA sequencing could be used to screen the gene mutations of HA patients, to carry out carrier detection and prenatal diagnosis of HA families efficiently, by combining with restriction endonuclease analysis and genetic linkage analysis.     

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.     

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.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

Detection of factor Ⅷ intron 1 inversion in severe haemophilia A

Objective Screening the intron 1 inversion of factor Ⅷ (FⅧ) in the population of severe haemophilia A(HA) in China and performing carrier detection and prenatal diagnosis. Methods Using LD-PCR to detect intron 22 inversions and multiple-PCR within two tubes to intron 1 inversions in sereve HA patients. Carrier detection and prenatal diagnosis were performed in affected families. Linkage analysis and DNA sequencing were used to verify these tests. Results One hundred and eighteen patients were seven diagnosed as intron 22 inversions and 7 were intron 1 inversions out of 247 severe HA patients. The prevalence of the intron 1 inversion in Chinese severe haemophilia A patients was 2. 8% (7/247). Six women from family A and 2 from family B were diagnosed as carriers. One fetus from family A was affected fetus. Conclusion Intron 1 inversion could be detected directly by multiple-PCR within two tubes. This method made the strategy more perfective in carrier and prenatal diagnosis of haemophilia A.     

河南地区苯丙酮尿症患者苯丙氨酸羟化酶基因突变研究

Objective To study the characteristics of the phenylalanine hydroxylase gene (PAH)mutations in patients with phenylketonuria (PKU) in Henan province, in order to provide basic information for genetic counseling and prenatal diagnosis. Methods Mutations of the PAH gene were detected in exons 1-13 with flanking introns of PAH gene by PCR and DNA sequencing in 47 families with PKU. Results A total of 25 different mutations were detected in 83 out of 94 PAH alleles (88. 3%). Among them,E79fX13, H271R and D415Y have not been reported previously. It was the first time that IVS10-14C＞Gmutation was reported in Chinese PKU population. The mutations p. R243Q, EX6-96A＞G, p. Y356X,IVS4-1G＞A, p. R111X, p. V399V and p. R413P, were the prevalent mutations with relative frequencies of 20. 5 %, 12.0%, 9.6%, 9. 6%, 8. 4%, 8. 4% and 7.2% respectively. Conclusion The mutations of the PAH gene in patients with classical phenylketonuria in Henan province were similar to that in other areas of China. Prenatal gene diagnosis for PKU by PAH gene sequencing is efficient for most PKU families.     

河南地区苯丙酮尿症患者苯丙氨酸羟化酶基因突变研究

Objective To study the characteristics of the phenylalanine hydroxylase gene (PAH)mutations in patients with phenylketonuria (PKU) in Henan province, in order to provide basic information for genetic counseling and prenatal diagnosis. Methods Mutations of the PAH gene were detected in exons 1-13 with flanking introns of PAH gene by PCR and DNA sequencing in 47 families with PKU. Results A total of 25 different mutations were detected in 83 out of 94 PAH alleles (88. 3%). Among them,E79fX13, H271R and D415Y have not been reported previously. It was the first time that IVS10-14C＞Gmutation was reported in Chinese PKU population. The mutations p. R243Q, EX6-96A＞G, p. Y356X,IVS4-1G＞A, p. R111X, p. V399V and p. R413P, were the prevalent mutations with relative frequencies of 20. 5 %, 12.0%, 9.6%, 9. 6%, 8. 4%, 8. 4% and 7.2% respectively. Conclusion The mutations of the PAH gene in patients with classical phenylketonuria in Henan province were similar to that in other areas of China. Prenatal gene diagnosis for PKU by PAH gene sequencing is efficient for most PKU families.     

Mutation analysis of 11 Chinese patients with attenuated mucopolysaccharidosis type Ⅰ

Objective Mucopolysaccharidosis type Ⅰ (MPS Ⅰ ) is an autosomal recessive diseaseresulting from the deficiency in the lysosomal enzyme α-L-iduronidase (IDUA). The present study was conducted to identify IDUA gene mutations in attenuated (MPS Ⅰ H/S and MPS Ⅰ S) patients with MPS Ⅰin northern China. Methods Fourteen exons with adjacent intronic sequences of the IDUA gene in 11 MPS Ⅰ patients were amplified by polymerase chain reaction (PCR), and the PCR products were sequenced directly and origin analysis was conducted. Results Seven mutations were detected in the 11 MPS Ⅰ patients, i.e., c. 236 C＞T(p. A79V), c. 266 G＞A(p. R89Q), c. 265 C＞T(p. R89W), c. 532G＞A(p.E178K), c. 589G＞A(p. G197S), c. 1037T＞G(p. L346R), and c. 1877 G＞A(p. W626X). All of them were known mutations. Six patients were homozygotes and 1 was heterozygote with nonsense mutation. In addition, 9 reported single nucleotide polymorphism (SNP) were detected, i. e., p. A8, p. A20, p. H33Q,p. R105Q, p. A314, p. A361T, p. T388, p. T410 and p. V454I. Conclusion The mutation spectrum of the IDUA gene in attenuated MPS Ⅰ Chinese patients may be different from that in patients from other countries.     

Mutation analysis of 11 Chinese patients with attenuated mucopolysaccharidosis type Ⅰ

Objective Mucopolysaccharidosis type Ⅰ (MPS Ⅰ ) is an autosomal recessive diseaseresulting from the deficiency in the lysosomal enzyme α-L-iduronidase (IDUA). The present study was conducted to identify IDUA gene mutations in attenuated (MPS Ⅰ H/S and MPS Ⅰ S) patients with MPS Ⅰin northern China. Methods Fourteen exons with adjacent intronic sequences of the IDUA gene in 11 MPS Ⅰ patients were amplified by polymerase chain reaction (PCR), and the PCR products were sequenced directly and origin analysis was conducted. Results Seven mutations were detected in the 11 MPS Ⅰ patients, i.e., c. 236 C＞T(p. A79V), c. 266 G＞A(p. R89Q), c. 265 C＞T(p. R89W), c. 532G＞A(p.E178K), c. 589G＞A(p. G197S), c. 1037T＞G(p. L346R), and c. 1877 G＞A(p. W626X). All of them were known mutations. Six patients were homozygotes and 1 was heterozygote with nonsense mutation. In addition, 9 reported single nucleotide polymorphism (SNP) were detected, i. e., p. A8, p. A20, p. H33Q,p. R105Q, p. A314, p. A361T, p. T388, p. T410 and p. V454I. Conclusion The mutation spectrum of the IDUA gene in attenuated MPS Ⅰ Chinese patients may be different from that in patients from other countries.