河南地区苯丙酮尿症患者苯丙氨酸羟化酶基因突变研究

目的 了解河南地区苯丙酮尿症(phenylketonuria,PKU)患者苯丙氨酸羟化酶(phenylalanine hydroxylase,PAH)基因突变情况,以便为苯丙酮尿症产前诊断和遗传咨询提供理论依据.方法 应用PCR产物直接测序对47例PKU患者及其父母PAH基因第1～13外显子及其两侧内含子进行序列分析.结果 在94条染色体中共检测到了83个PAH基因突变位点,检出率为88.3%(83/94),共发现了25种突变,其中突变E79fX13、H271R和D415Y国内外未见报道,突变VS10-14C＞G为国内首次报道.河南地区PKU患者的PAH基因突变集中在第6、7和11外显子,常见的7种突变是p.R243Q(20.5%)、EX6-96A＞G(12.0%)、p.Y356X(9.6%)、VS4-1G＞A(9.6%)、p.R111X(8.4%)、p.V399V(8.4%)、p.R413P(7.2%).结论 河南地区PKU患者PAH基因突变与中国其他地区相似,通过PAH基因直接测序可对大部分的PKU家系进行产前诊断.

Abstract：

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.     

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.     

河南省苯丙酮尿症患者苯丙氨酸羟化酶基因突变的构成

目的 了解河南省苯丙酮尿症(phenylketonuria,PKU)患者苯丙氨酸羟化酶(phenylalanine hydroxylase,PAH)基因突变的特点,为临床遗传咨询、基因诊断及产前诊断提供科学依据.方法 应用聚合酶链反应和DNA正反测序技术对34例经典型PKU患者的PAH基因全部13个外显子及两侧部分内含子进行鉴定分析.结果 34例患者共68个PAH等位基因中共检出23种致病突变(包括错义突变12种、无义突变4种、剪接突变4种和缺失3种)和9种其它基因变异.致病基因突变的总检出率为92.65%(63/68).第7外显子的基因突变种类最多,其次是第5外显于和第11外显子.检索PAH基因突变数据库和查阅相关文献,确定有2种突变[A156P和P69_S70delinsP(delCTT)]国际上未见报道,4种突变(IVS2+5G＞C、G332E、IVS10-14C＞G、L367＞Wfs)国内未见报道.结论 河南省PKU患者PAH基因的突变构成及频率与中国其它地区人群稍有不同.     

甘肃地区苯丙酮尿症患者苯丙氨酸羟化酶基因突变分析

.2%),IVS4-1G>A(5.2%),较常见的突变有Y356X(3.4%),R111X(3.4%),INS7+2T>A(3.4%).结论 甘肃地区PAH基因突变与中国其他地区相似,但部分突变基因比例存在明显的差异.     

经典型苯丙酮尿症基因全长外显子的突变检测和分析

目的探讨中国PKU患者PAH基因突变特征。方法运用PCR-SSCP及PCR-DNA直接测序检测40例经典型PKU患者和30例正常对照的PAH基因。结果在PAH基因上8个外显子共发现11种突变和3种多态,其中R243Q和Y204C为两个高频突变位点,突变率分别为27.5%和10%,280 insT、M276K、M276R、IVS10nt+32T→A、IVS4nt+46C→T、H290R是首次发现的新突变。结论中国PKU患者基因外显子突变是以两个突变热点和罕见突变并存为特征。     

经典型苯丙酮尿症的治疗分析

作者选用经济,易得的普通低本丙氨酸食物,经过合理调配对1例经典型苯丙酮尿症患者进行了饮食治疗,评价近一年来踊跃随访和定期监测的结果,认为治疗效果满意。本文采用的这种治疗方案与其他治疗方法相比,更适合于普通家庭的经济承受能力,具有一定的推广和应用价值。     

高分辨率熔解曲线分析技术检测苯丙酮尿症患者的苯丙氨酸羟化酶基因突变

目的 应用高分辨率熔解曲线（HRM）分析技术检测苯丙酮尿症患者苯丙氨酸羟化酶基因突变.方法 利用PCR扩增13例苯丙酮尿症（PKU）患者的苯丙氨酸羟化酶（PAH）基因第6、7、11及12外显子,然后对PCR产物进行HRM分析,通过DNA测序对HRM结果进行验证.结果 在13例PKU患者的26个PAH等位基因中共检测出5种不同突变基因,总检出率为38.5％.常见的突变类型是R243Q和A434D.检测出两种多态性位点为Q232Q和V245V.HRM分析结果与测序结果完全一致.结论 HRM技术具有简单、快速、易操作、准确等优点,可用于PKU患者PAH基因突变筛查.     

新疆地区苯丙氨酸羟化酶基因的突变研究

目的 了解新疆地区苯丙氨酸羟化酶(phenylalanine hydroxylase,PAH)基因的突变规律及特点.方法 应用聚合酶链反应一单链构象多态性分析及基因测序列方法 ,检测46例苯丙酮尿症患者PAH基因第3、5、6、7、11和12外显子及其两侧内含子序列.结果 在92个PAH等位基因中共检出20种不同的突变基因,总检出率为73.9%(68/92).其中常见基因突变R243Q、EX6-96A＞G、R111X、Y356X和V399V与我国北方地区基本类似.较常见基因突变F161S、L255S、P281L和R413P与国内其他地区相比差异较大.E280G和A434D为在国际上第2次检出;L255S、P281L、R261Q和165T为在国内第2次检出.新疆少数民族也发现了13种PAH基因突变,均系在本民族中首次报道,其突变基因的类型表现出鲜明的民族特色.结论 从对新疆地区PAH突变基因的研究结果 来看,该地的遗传基因不仅具有独立、保守的特性,而且还存在着相互交叉、相互融合的特征.     

苯丙氨酸羟化酶基因的六种新型突变

目的　检测中国苯丙酮尿症 ( phenylketonuria ,PKU )患者苯丙氨酸羟化酶 (phenylalaninehy droxylase ,PAH)基因新的突变位点。 方法　应用聚合酶链反应 单链构象多态性及DNA直接测序检测 40例经典型PKU患者和 3 0名正常对照的PAH基因。结果　在PAH基因上共发现 11种突变和 3种多态 ,3 0名正常对照者PAH基因未发现异常。结论　经与国际PAH基因突变数据库比较 ,确认M 2 76K、M 2 76R、2 80insT、IVS10nt 3 2T→A、IVS4nt 4 7C→T是国际上首次发现的突变 ,H 2 90R是中国PKU患者基因上首次发现的新型突变。     

Eight new mutations of the phenylalanine hydroxylase gene in Italian patients with hyperphenylalaninemia

This report identifies eight new mutations of the phenylalanine hydroxylase gene detected in Italian patients with hyperphenylalaninemia. The trivial name of the mutations, predicted phenotypic effect, and population of origin (Italian region) are as follows: F55L (nonconservative change: classic, moderate, mild PKU ?; Sicily), IVS2nt-13 (splicing defect, classic PKU; Tuscany), I65N (nonconservative change classic, moderate, mild PKU ?; Sicily), H201Y (non-PKU HPA; Sicily), I269L (non-PKU HPA, or polymorphism; Sicily), IVS7nt3 (splicing defect or polymorphism; Sicily), I283N (classic PKU; Sicily), IVS12nt2 (splicing defect, classic PKU; Sicily and Apulia). In Sicily, the relative frequency of mutations F55L, I65N, H201Y, I269L, IVS7nt3, I283N, IVS12nt2 is < 1%. The seven new mutations identified in the Sicilian population increase the remarkable genetic heterogeneity typical of this population with an estimated homozygosity value at the PAH locus of 0.041. Hum Mutat 11:240–243, 1998. © 1998 Wiley-Liss, Inc.     

天津及周边地区苯丙氨酸羟化酶基因突变谱和新突变分析

目的 分析天津地区人苯丙氨酸羟化酶(phenylalanine hydroxylase gene,PAH)基因突变谱,明确本地区该基因突变类型和特点,为遗传咨询和产前基因诊断提供科学依据.方法 用聚合酶链反应-单链构象多态、变性高效液相色谱法和DNA测序法对天津及河北等地99例已确诊各种类型苯丙酮尿症患儿基因组DNA进行PAH全基因13个外显子分析.结果 全基因共检出41种突变,含错义突变22种、无义突变7种、剪接位点突变9种和缺失突变3种.其中新突变6种(IVS3nt+1g→a、A165D、Q301X、G344D、P362L和R413G).198个PAH等位基因突变总检出率为93.94%.结论 天津及周边地区PAH基因突变谱广、遗传异质性高,一些常见突变的发生频率与以往报道的地域分布略不同.     

127例PKU患者PAH基因第12外显子点突变及其频率研究

目的　了解中国人苯丙酮尿症 ( phenylketonuria,PKU)患者的苯丙氨酸羟化酶( phenylalanine hydroxylase,PAH)基因第 12外显子点突变种类和频率。方法　应用单链构象多态性( single strand conformation polymorphism,SSCP)、变性梯度凝胶电泳 ( denaturing gradient gelelectrophoresis,DGGE)、DNA测序分析了 12 7例 PKU患者的 PAH基因第 12外显子点突变种类及频率。结果　 DNA测序分析显示 10例患者存在 R4 13P、S4 11X、R4 0 8W、R4 0 8Q 4种杂合突变 ,其突变频率分别为 2 .76 %、0 .39%、0 .39%、0 .39% ,S4 11X突变为中国人中首次报道。 SSCP分析仅发现 2例 R4 13P杂合突变 ,DGGE分析显示 10例出现 3种类型的异常电泳带型。R4 13P突变在南北方人之间、在经典型 PKU和高苯丙氨酸血症之间的分布差异无显著性。结论　 DGGE对 PAH基因第 12外显子点突变检出率明显高于 SSCP。 DGGE结合 DNA测序是明确 PAH基因第 12外显子点突变种类和频率较好的方法。 R4 13P突变在南北方人中分布无明显差异     

中国北方地区苯丙氨酸羟化酶基因的突变构成

目的了解中国人苯丙氨酸羟化酶（phenylalanine hydroxylase,PAH）基因的突变构成。方法应用PCR单链构象多态结合序列分析检测230例苯丙酮尿症患儿PAH基因全部外显子及其两侧内含子。结果（1）在460个PAH等位基因中检测出75种不同的突变基因,总检测率达94.6%（435/460）,其中3种突变基因（S251-R252〉SfsX89、Y387D和A389G）尚未见到报道。常见的突变基因为：R243Q（21.7%）、EX6-96A〉G（10.2%）、R111X（8.3%）、R413P（6.5%）和Y356X（6.1%）。较常见的突变基因为：V399V（4.1%）、IVS4-1G〉A（3.5%）、IVS7＋2T〉A（2.2%）和R241C（2.2%）。大部分突变集中在第3、5、6、7、11和12外显子及其两侧内含子区域。（2）检测出10种多态性位点,突变率高的4个位点IVS3-22C〉T（56.7%）、IVS10＋97G〉A（75.9%）、Q232Q（89.0%）和V245V（81.9%）,提示PAH基因cDNA序列存在人种差异。结论中国人PAH基因的突变构成与欧洲人群完全不同,与亚洲其它人群有频率的差异。     

A comprehensive study of phenylalanine hydroxylase gene mutations in the Iranian phenylketonuria patients

Phenylketonuria (PKU) is a metabolic disorder caused by mutations in the phenylalanine hydroxylase (PAH) gene. After thalassemia, PKU is considered as the most common autosomal recessive diseases in the Iranian population. Therefore, an efficient diagnostic strategy is required to identify disease-causing mutations in this population. Following our first report in 2003, here we presented a comprehensive study on the mutation spectrum of the PAH gene in the Iranian population. This study was performed on 280 unrelated chromosomes from 140 Iranian patients with classic PKU. All 13 exons as well as exon-intron boundaries of the PAH gene were analyzed by direct DNA sequencing. Thirty four different mutations were identified by a mutation detection rate of 100%. IVS10-11G > A, p.P281L, R261Q, p.F39del and IVS11+1G > C were the most prevalent mutations with frequencies of 26.07%, 19.3%, 12.86%, 6.07 and 3.93%, respectively. All other mutations represented a relative frequency less than 3.5%. The data from this study provided a comprehensive spectrum of the PAH gene mutations which can facilitate carrier detection and prenatal diagnosis of PKU disease in the Iranian population.     

Comparative diagnostic value of phenyla-lanine challenge and phenylalanine hydroxylase activity in phenylketonuria

Serum phenylalanine (phe) concentrations during and following phe challenges and liver phenylalanine hydroxylase (PH) activity were compared in 13 phenylketonuric (PKU) patients. These patients were separated into two groups: eight patients with no detectable PH activity (PH°) and five patients with residual PH activity (PH^-) ranging from 9 to 24% of the activity obtained in 10 non-PKU subjects. The rise in serum phe concentration during 3 days of oral loading did not differentiate the two groups. However, the difference in serum phe concentration of the PH° and PH^- groups reached statistical significance at 24 h postloading (p<0.01). We concluded that combined results from multiple measurements during the oral challenge, namely serum phe concentration after termination of loading, serum phe clearance rate, post-loading phe tolerance index and urinary metabolite excretion, make a better indicator for predicting residual PH activity for the majority of PKU subjects than peak phe concentrations during phe challenge.