苯丙酮尿症患儿苯丙氨酸羟化酶exon6基因、exon7基因突变的研究

目的 探讨山西省苯丙酮尿症(PKU)患儿的苯丙氨酸羟化酶(PAH)exon6 基因、exon7 基因的突变特征.方法 通过测序及序列比对的方法对56 例PKU 患儿和112 例健康儿童的336 个PAH exon6 基因、exon7 基因进行序列分析,以确定其突变位点、性质和频率.结果 通过序列分析,发现在PKU 患儿和健康儿童中均高频率的出现Q232Q(CAA→CAG)、V245V(GTG→GTA)两种同义突变,其中cDNA 696 位点的频率高达96.2%,cDNA 735 位点的频率高达76.1%.健康儿童的其他序列与Genbank 完全相同.而PKU 患儿的基因序列中还发现了9 种共计37 个突变基因,占全部PAH 突变基因的33.04%.exon 6 仅发现一种突变基因Y204C,突变频率达9.8%;exon 7 中R243Q 的突变率最高,占10.7%,其次为Ivs7 +2 T ＞A,占5.4%,其余的G247V、R252Q、L255S、R261Q、T278I 和E280K 分别占0.9%、0.9%、0.9%、0.9%、2.7%和0.9%.9 种突变都在之前文献中有过报道,其中有7 种错义突变和2 种剪接位点突变.结论 明确了PAH exon6 基因、exon7 基因的突变种类和分布等特征,表明exon6 基因、exon7 基因中Y204C 和R243Q属于山西人群中PAH 基因突变的热点.     

FⅨ基因全外显子测序技术在血友病B基因携带者检测及产前基因诊断中的应用

目的 探索应用FⅨ基因全外显子测序技术进行血友病B(HB)基因携带者检测和产前基因诊断.方法 在取得5个无血缘关系的汉族HB家系成员知情同意后,采集相关家系成员标本.3个产前诊断标本中,2例为胎儿脐血标本,1例为羊水标本.从标本中提取基因组DNA,通过PCR扩增FⅨ基因所有外显子及其侧翼序列,将产物进行全外显子直接测序.结果 5个家系的HB患者以及FⅨ基因携带者共检出5种突变:c.484 C＞T (p.R162X)、c.1022G＞A(p.R341Q)、c.1135C＞T(p.R379X)、c.799C＞T(p.H267Y)和c.1232G＞T(p.S411I).在产前诊断中,发现1例c.484 C＞T(p.R162X)突变,另2例未检出FⅨ基因突变的胎儿出生后血浆FⅨ促凝活性分别为52.7％和76.2％.结论 首次报道中国汉族HB家系FⅨ基因c.1022G＞A(p.R341Q)、c.1135C＞T(p.R379X)、c.799C ＞T (p.H267Y)和c.1232G＞T(p.S411I)突变;在严格的质量控制下,FⅨ基因全外显子直接测序是一种快速准确的诊断HB基因携带者及产前基因诊断的方法.     

新疆少数民族苯丙酮尿症患者的突变基因分析

目的 探讨新疆少数民族苯丙酮尿症(PKU)患者的基因突变特征,为有针对性的防治策略提供科学依据.方法 采用单链构象多态性分析技术和PCR产物直接测序方法 ,检测12例少数民族PKU患者的苯丙氨酸羟化酶(PAH)基因突变.结果 从12例维吾尔族、回族和哈萨克族PKU患者(24个PAH等位基因)中,检出13种基因突变,包括错义突变8种、无义突变1种、剪切位点突变3种,其中突变频率最高的是EX6-96A＞G和P281L,EX6-96A＞G常见于国内和亚洲地区,P281L多见于欧洲各地.突变频率较高的R243Q、R111X、R176X和F161S 4种突变中,其中R243Q是我国北方地区居首位的突变,R111X处于第3位.而R176X和F161S在世界范围内都极为少见,尤其F161S是具有中国特色的基因突变,是第2次在中国人中发现.结论 新疆少数民族中的PAH突变基因不仅与亚洲黄种人和欧洲及拉美人种表现出密切的联系,而且也存在着明显的差异,形成了自身独立的遗传规律和特点,是我国一个十分特殊的PAH突变基因分布区域.     

FANCJ基因在成人急性髓系白血病中的突变图谱

目的:检测分析急性髓系白血病(acute myeloid leukemia, AML)患者FANCJ基因突变情况,为研究FANCJ突变类型的AML疾病致病机理奠定基础,同时为其疾病防治提供指导。方法:在FANCJ基因蛋白编码区设计引物,采用PCR扩增及sanger测序法检测222例初诊AML患者骨髓细胞中FANCJ基因编码区突变情况,同时检测AML患者黏膜上皮组织FANCJ基因突变情况;采用NCBI Blast在线生物信息学软件分析FANCJ基因突变在不同物种中的进化保守性。结果:测序分析显示,FANCJ基因在蛋白编码区的11个位点出现突变,分别为exon5:c.G430A:p.A144T,exon6:c.A587G:p.N196S,exon9:c.C1255T:p.R419W,exon10:c.G1442A:p.G481D,exon11:c.C1609G:p.L537V,exon16:c.C2360T:p.P787L,exon17:c.C2440T:p.R814C,exon19:c.C2608T:p.H870Y,exon19:c.A2686G:p.I896V,exon19:c.C2830G:p.Q944E,exon20:c.G3412A:p.D1138N,其中A144T、N196S、R814C、I896V及Q944E突变存在复现性;另外,A144、R419、G381、L537、P787、H870、Q944及D1138位点在不同物种中高度保守。结论:在222例AML患者中发现26名患者中存在FANCJ突变,并且突变位点在不同物种中相对保守,功能重要,这为接下来研究FANCJ突变类型的AML疾病致病机理奠定基础,同时为疾病防治提供指导。     

赤道几内亚比奥科岛G6PD缺乏症分子流行病学研究

目的 探讨非州西部赤道几内亚比奥科岛(Bioko Island)人群的葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症的发生率及基因型. 方法 在2012年1月至5月期间,用荧光斑点法对2 187名比奥科岛当地居民进行G6PD缺乏症筛查.采用高分辨熔解曲线(High-resolution melting,HRM)分析G6PD缺乏的标本的c.202 G＞A与c.376 A＞G.对HRM筛选不出突变的G6PD酶学缺乏的样本,针对非洲的其他突变类型:c.542 A＞T(rs5030872)、c.680 G＞A(rs137852328)、c.968 T＞C(rs76723693)进行PCR-DNA测序. 结果 赤道几内亚比奥科岛人群的G6PD缺乏症总发生率为8.64％ (189/2 187),其中男性84例(9.04％,84/929),女性105例(8.34％,105/1 258),男女检出率比为1.08:1.在189例G6PD缺乏标本中共检出两种基因类型,其中包括G6PD A变异体(c.376 A＞G/c.202 G＞A)186例(98.41％,186/189G6PD Betica(c.376 A＞G/c.968T＞ C)3例(1.59％3/189). 结论 赤道几内亚比奥科岛是G6PD缺乏症高发区,基因型比较单一.HRM技术可用于非洲地区G6PD缺乏症的临床诊断和流行病学研究.     

新疆地区汉族苯丙酮尿症患儿苯丙氨酸羟化酶基因突变分析

目的分析新疆地区汉族苯丙酮尿症(PKU)患儿苯丙氨酸羟化酶(PAH)基因的突变规律和特点。方法用PCR产物直接测序法、基因芯片捕获和二代高通量测序技术对71例汉族PKU患儿及其父母的PAH基因启动子、第1~13外显子及其旁侧内含子等区域进行PAH基因突变分析,并与西北4省及日本、欧洲等进行比较。结果在新疆地区71例汉族PKU患儿142条PAH等位基因中检测出37种突变基因,总检出率为90.1%(128/142),且以错义突变(64.9%)、剪接位点突变(13.5%)、无义突变(13.5%)为主,大部分突变主要分布在第7、6、3、12、2、11外显子和第4内含子中,最常见的错义突变是R243Q(21.8%)、R53H(7.7%);最常见的剪接位点突变为EX6-96AG(6.3%)、IVS4-1GA(4.9%)和V399V(4.2%),最常见的无义突变为R111X(4.9%)、Y356X(4.9%)。新疆地区汉族PKU患儿R53H突变的检出率(7.7%)高于西北其他4省,且发现一PAH基因新突变P225S(c.673CT)。结论新疆地区汉族PKU患儿PAH基因突变构成接近于西北其他4省,而与欧洲、日本等完全不同,具有其独特保守的地域特征。     

内蒙古地区苯丙酮尿症苯丙氨酸羟化酶基因突变的检测

目的　了解内蒙古地区苯丙酮尿症 (PKU)病人苯丙氨酸羟化酶 (PAH)基因突变类型和频率。方法　采用聚合酶链反应 (PCR)扩增 ,单链构象多态性分析 (SSCP)、DNA直接测序的方法 ,对内蒙古地区 2 2个PKU家系PAH基因外显子 3、5、6、7、1 0、1 1、1 2 ,进行检测分析。结果　检出 1 0种苯丙氨酸羟化酶基因的点突变。R2 4 3Q (8/44 )、R2 5 2Q (1 /44 )、R2 6 1Q (1 /44 )、G2 39D (1 /44 )、IVS7nt(2 ) (1 /44 )、Y2 0 4C(5 /44 )、Y35 6X(6 /44 )、R4 1 3P(1 /44 )、R1 1 1X(1 /44 )、Y1 6 1S(1 /44 ) ,经检索国际PAH基因突变数据统计库 ,确认G2 39D(G→A)为首次发现的新突变。结论　R2 4 3Q、Y35 6X、Y2 0 4C是内蒙地区人群中PAH基因的主要突变位点。以Y35 6X的突变率明显高于、R4 1 3P低于北方人群为特征。     

连云港地区苯丙酮尿症患儿苯丙氨酸羟化酶基因突变谱的构建及其应用

目的分析连云港地区苯丙酮尿症(PKU)患儿苯丙氨酸羟化酶(PAH)基因突变特点,构建PAH基因突变谱,探讨PKU患儿基因型与表型的关系。方法用二代测序技术分析29例PKU患儿及其父母PAH基因第1~13外显子及两侧内含子序列,用AV值评分法进行基因型-生化表型的预测。结果 29例PKU患儿的58个等位基因中共检测出50个突变,检出率为86.2%,常见突变依次为R243Q(11/50,22.0%),R241C(4/50,8.0%)和V399V(4/50,8.0%);R169S和P292L为新发突变;通过基因型预测的生化表型与患儿实际生化表型的一致率为80.0%,其中经典型PKU的预测一致率为83.3%,患儿治疗前血苯丙氨酸水平与AV值评分呈显著负相关(r=-0.71,P0.05)。结论连云港地区PKU患儿PAH基因突变谱与其他地区有差别,基因型与表型之间具有相关性,对临床治疗具有重要指导意义。     

海口地区新生儿G6PD基因突变分析

目的 了解海口地区新生儿葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症的发生率及基因突变特点. 方法 用荧光斑点法对2016年1月1日至2016年2月24日出生于海口的5 295例新生儿进行G6PD活性筛查,对173例初筛阳性的标本用多色探针荧光PCR熔解曲线法(MMCA)进行基因分型.结果 本次筛查发现海口地区新生儿群体的G6PD缺乏症发生率为3.87％ (205/5 295),其中男女发生率分别为4.99％(142/2 848)和2.57％ (63/2 447).173例初筛阳性标本中检出142例(82.08％)有基因突变,基因携带率为3.18％(142/5 295/84.39％).共检出6种基因突变类型,含74例(52.11％) c.1376 G＞T,33例(23.24％)c.1388 G＞A,13例(9.15％)c.95 A＞G,8例(5.63％)c.1024 C＞T,4例(2.82％) c.871 G＞A,5例(3.52％) c.392 G＞T,并检出3例(2.11％)c.1376 G＞T复合c.1388 G＞A突变、1例(0.71％) c.392 G＞T复合c.517 T＞C突变、1例(0.71％)c.95 A＞G复合c.1388 G＞A突变. 结论 海口地区是G6PD缺乏症高发地区,c.1376G＞T、c.1388G＞A和c.95 A＞G是主要的3种基因突变型.     

新疆地区230例苯丙氨酸羟化酶缺乏症患儿基因突变分析

目的 探讨新疆地区苯丙氨酸羟化酶(PAH)缺乏症患儿基因变异频率和分布特征。方法 将2015年1月1日至2023年2月28日在乌鲁木齐市妇幼保健院确诊的230例PAH缺乏症患儿纳入研究,分析PAH基因变异情况以及比较不同表型患儿的PAH基因变异位点。结果 新疆地区230例PAH缺乏症患儿共检出441个PAH基因变异位点,总检出率为95.87%。其中,227例患儿检测到2个变异位点,2例患儿仅检测到1个变异位点,1例患儿检测到3个变异位点;复合杂合变异217例,纯合变异10例。高频变异位点为c.158G>A[23.39%(102/441)]、c.728G>A[11.70%(51/441)]、c.688G>A[5.05%(22/441)]、c.721C>T[3.90%(17/441)]、c.611A>G[3.67%(16/441)]、c.1238G>C[3.21%(14/441)]。经典型PKU的高频变异位点为c.728G>A、c.331C>T和c.782G>A;轻度PKU的高频变异位点为c.721C>T、c.1068C>A...     

Mutation analysis of phenylketonuria patients from Morocco: High prevalence of mutation G352fsdelG and detection of a novel mutation p.K85X

Objective:The knowledge of the molecular basis of the Phenylketonuria (PKU, MIM# 261600) in different countries provides relevant information for undertaking specific and rational mutation detection strategies in each population and for the implementation of adequate dietary and cofactor treatment. There are no data available in Moroccan population.Design and methods:In this work we describe the genetic analysis by mutation scanning using denaturing gradient gel electrophoresis (DGGE) and subsequent direct sequencing of 20 different PKU families from Morocco. We have also included the study of 7 Moroccan PKU patients living in Spain detected by the Spanish newborn screening program.Results:The mutational spectrum in the first sample included eight different changes, one of them, p.K85X, was novel. The most common mutation was the frame shift change p.G352fsdelG identified in 62.5% of the mutant chromosomes studied. Other changes (p.R176X, IVS10nt-11 g > a, p.W120X, p.A165T, p.R243X and p.R243Q) were identified, respectively, in 2 or 3 mutant alleles. All detected mutations were severe according to the classical phenotype of the patients. In the 7 patients living in Spain we have detected 4 severe mutations (p.G352fs, p.R176X, Y198fs and Exon3del) and also milder changes such as p.A403V, p.S196T, p.D145V and p.R408Q detected in 3 mild hyperphenylalaninemia (MHP) patients and a novel p.L258P found in a mild PKU patient.Conclusion:The results provide important information on the distribution of PKU mutations in this Mediterranean area gaining insight into the genetic epidemiology of the disease.     

Structural and functional analyses of mutations of the human phenylalanine hydroxylase gene

BACKGROUND: Phenylketonuria (PKU) is an inborn error of metabolism that results from a deficiency of phenylalanine hydroxylase (PAH). We demonstrated PAH mutational spectrum from patients with PKU, including 10 novel and 3 tetrahydrobiopterin (BH(4))-responsive mutations. In this study, 11 PAH missense mutations, including 6 novel mutations (P69S, G103S, L293M, G332V, S391I, A447P) found in our previous study, 2 mutations common in east Asian patients with PKU (R243Q, R413P), and 3 tetrahydrobiopterin (BH(4))-responsive mutations (R53H, R241C, R408Q) have been functionally and structurally analyzed. METHODS: A transient protein overexpression system and an in vitro BH(4)-responsiveness study were used. The effects of PAH missense mutations on the PAH protein structure were also analyzed. To determine the conservation of 12 mutated residues, PAH was aligned using BLAST against full genomic sequences of 221 different species. Model structures of PAH protein and the composite tetramer were constructed using the software program, SHEBA. RESULTS: No PAH activity was detected for some mutants. However, the residual activities associated with other mutants ranged over a wide spectrum. The missense mutations responsive to BH(4) were not highly conserved throughout the 43 species in the multiple sequence alignment that encode PAH. The composite model structure of PAH revealed that dimer stability was reduced in the BH(4)-responsive mutants, whereas tetramer stability remained normal. CONCLUSION: This expression study analyzed PAH mutations and model structures of mutant PAH proteins are proposed. Correlation between the proposed mutant PAH structures and functions are suggested.     

遗传性多发性骨软骨瘤的基因突变筛查及基因型与表型关系的研究

目的建立HME的基因突变筛查方法,并探讨其基因型与临床表型的关系.方法根据临床诊断将15例HME先证者分为轻度(M)和重度(Ⅰ S、ⅡS、ⅢS)4型,运用PCR扩增产物直接测序法对先证者及其家系成员进行EXT1和EXT2基因序列分析,筛查其EXT1和EX72基因突变,并分析基因型与临床表型之间的关系.结果 15例HME先证者中有9例为EXT1基因突变,6例为EXT2基因突变,其中EXT1基因I8+2T＞G、c.1182deIG、c.1108G＞T(p.E370X)、c.335de1A、c.361C＞T(p.Q121X)和c.1879_1881delCAC为国际上新发现的基因突变位点.EXT1基因突变患者临床表型分别为M型2例(22.2%,2/9)、Ⅰ S型2例、ⅡS型4例和ⅢS型1例,而EXT2基因突变患者M型有5例(83.3%,5/6),另1例为ⅡS型.结论本研究建立了HME准确、简便的EXT1和EXT2基因突变筛查方法,6个EXT1基因突变I8+2T＞G、c.1182delG、c.1108G＞T(p.E370X)、c.335delA、c.361C＞T(p.Q121X)和c.1879_1881delCAC为国际首次报道,EXT1基因突变患者相比EXT2基因突变患者临床表型要更严重.     

Molecular advances in thyroglobulin disorders

Synthesis of tri-iodothyronine (T(3)) and thyroxine (T(4)) follows a metabolic pathway that depends on the integrity of the thyroglobulin structure. This large glycoprotein is a homodimer of 660 kDa synthesized and secreted by the thyroid cells into the lumen of thyroid follicle. In humans it is coded by a single copy gene, 270 kb long, that maps on chromosome 8q24 and contains an 8.5 kb coding sequence divided into 48 exons. The preprotein monomer is composed of a 19-amino acid signal peptide followed by a 2749-amino acid polypeptide. In the last decade, several mutations in the thyroglobulin gene were reported. In animals, four of them have been observed in Afrikander cattle (p.R697X), Dutch goats (p.Y296X), cog/cog mouse (p.L2263P) and rdw rats (p.G2300R). Mutations in the human thyroglobulin gene are associated with congenital goiter or endemic and nonendemic simple goiter. Thirty-five inactivating mutations have been identified and characterized in the human thyroglobulin gene: 20 missense mutations (p.C175G, p.Q310P, p.Q851H, p.S971I, p.R989C, p.P993L, p.C1058R, p.C1245R, p.S1447N, p.C1588F, p.C1878Y, p.I1912V, p.C1977S, p.C1987Y, p.C2135Y, p.R2223H, p.G2300D, p.R2317Q, p.G2355V, p.G2356R), 8 splice site mutations (g.IVS3-3C>G, g.IVS5+1G>A, g.IVS10-1G>A, g.IVS24+1G>C, g.IVS30+1G>T, g.IVS30+1G>A, g.IVS34-1G>C, g.IVS45+2T>A) 5 nonsense mutations (p.R277X, p.Q692X, p.W1418X, p.R1511X, p.Q2638X) and 2 single nucleotide deletions (p.G362fsX382, p.D1494fsX1547). The thyroglobulin gene has been also identified as the major susceptibility gene for familial autoimmune thyroid diseases (AITD) by linkage analysis using highly informative polymorphic markers. In conclusion the identification of mutations in the thyrogobulin gene has provided important insights into structure-function relationships.     

FH clinical phenotype in Greek patients with LDL-R defective vs. negative mutations

BACKGROUND: Familial hypercholesterolaemia (FH) is caused by mutations in the low-density lipoprotein receptor gene and the gene encoding apolipoprotein B-100, affecting one in 500 individuals. METHODS: One hundred and eighty-three Greek FH patients were screened for mutations on the LDLR and ApoB genes. RESULTS: We identified mutations in 67 probands and 11 relatives. Sixteen mutations located in eight different exons and the promoter of the LDLR were discovered. Among them 10 were missense mutations (C6W, S265R, A370T, Q363P, D365E, V408M, A410T, A517T, G528D, G571E), two were nonsense mutations (Q363X and C660X), three were splice defects (2140 + 5G-->A and 2140 + 9C-->T, 1706 - 10G-->A), and one was a nucleotide substitution (- 45delT) on the promoter. None of the subjects carried any apoB mutation. The detection rate of mutations in this study was 43%. From the above mutations, A410T, A519T and the splice site defects 2140 + 9C-->T were detected for the first time in the Greek population. Among them V408M, G528D, C6W and S265R account for 73% of heterozygous FH probands. V408M mutation is more common in Central West, while C6W is more common in Central East. Separating the patients into two groups (receptor defective and receptor negative) we found that the receptor negative group had higher levels of total cholesterol, low-density lipoprotein cholesterol and higher prevalence of tendon xanthomas compared with the receptor-defective group. DISCUSSION: The homogenous molecular basis of familial hypercholesterolaemia in Greece facilitates the application of a DNA diagnostic strategy based on the origin of the patient. The early mutation analysis would add valuable information on the severity of the disease.     

1例植物固醇血症的家系调查及致病基因突变研究

目的探讨1例植物固醇血症家系及其致病基因突变。方法对1例诊断为植物固醇血症的患者及其家系成员进行家系调查;通过PCR扩增先证者及其家系成员基因组DNA中ABCG5及ABCG8基因的所有外显子及其侧翼序列,采用Sanger测序法对PCR产物进行基因测序;采用Polyphen2及Mutation Taster生物信息学软件预测突变的致病性。结果 Sanger测序法发现先症者及家系成员中存在多个基因突变,其中ABCG5基因发现3个突变,分别为外显子1 c.64CT(p.Q22X)杂合无义突变、外显子10 c.1336CT(p.R446X)杂合无义突变、外显子13 c.1810CG(p.Q604E)杂合错义突变;ABCG8基因发现4个突变,分别为(ATG前)-19TG纯合突变、外显子2 c.161AG(p.Y54C)纯合错义突变、外显子13 c.1895TC(p.V632A)纯合错义突变、外显子4和5间的内含子g.12902TC纯合突变。Polyphen2及Mutation Taster软件预测ABCG5基因中c.64CT及c.1336CT为致病突变,其他基因突变均为非致病性的多态性位点。结论 ABCG5基因c.64CT及c.1336CT复杂杂合突变是该植物固醇血症家系的基因发病机制。     

Mutational spectrum of the phenylalanine hydroxylase gene in patients with phenylketonuria in the central region of China

Phenylketonuria (PKU, OMIM 261600) caused by phenylalanine hydroxylase (PAH) deficiency is an autosomal recessive disease that is characterized by abnormalities of phenylalanine metabolism. In this study, a total of 77 patients, originating from the central region of China and who were diagnosed with PAH deficiency at the third affiliated hospital of Zhengzhou University, were enrolled in this study. The 13 exons and 12 flanking introns of the PAH gene were analyzed by Sanger sequencing and next generation sequencing. The sequencing data were aligned to the hg19, PAHvdb and HGMD databases to characterize the genotypes of PKU patients, and genotype–phenotype correlations and BH4 responsiveness predictions were performed using BIOPKUdb. In total, 149 alleles were characterized among the 154 PKU alleles. These mutations were located in exons 2–13, and intron 12 of the PAH gene, with a relative frequency of ≥5%, for EX6-96A>G, p.R241C, p.R243Q, p.V399V and p.R53H. Additionally, a novel variant, p.D84G, was identified. The genotype correlated with clinical symptoms in 33.3–100% of the cases, depending on the disease severity, and BH4 responsiveness predictions show that only five patients with MHP-PKU and one patient with Mild-PKU were predicted to be BH4 responsive. In conclusion, we have characterized the mutational spectrum of PAH in the central region of China and have identified a novel mutation. The hotspot mutation information might be useful for screening, diagnosis and treatment of PKU.