遗传性皮肤病

20 0 4 2 130　 X性连锁少汗性外胚层发育不良家系 ED 1基因突变检测 /陈建军 (合肥医大皮研所 )… //中华皮肤科杂志 .- 2 0 0 3,36 (10 ) .- 553～ 555收集 2个 X性连锁少汗性外胚层发育不良家系外周血标本 ,采用聚合酶链反应结合 DNA直接双向测序的方法检测。结果显示 ,家系 1中 ED1基因的第 8个外显子下游与内含子 8交界处存在一个新的剪接点缺失突变 (IVS8 5del G) ,家系 2中第 9个外显子处存在一个错义突变 (A959G)。这些突变未在两个家系的正常人及 188例无关正常对照者中出现。图 7表 1参 6　(邓翠霞 )2 0 0 4 2 131　遗传性…     

X连锁无汗性外胚叶发育不良家系的基因突变检测

目的 鉴定X连锁无汗性外胚叶发育不良(EDA)家系的基因突变及其突变类型,为建立对该病的基因诊断与遗传咨询提供依据。方法 应用聚合酶链反应-单链构象多态性(PCR-SSCP)分析法,结合DNA测序,检测了汉族人X连锁EDA一家系的基因突变位点与突变方式。结果 EDA致病基因(EDA1基因)外显子1的PCR产物经SSCP分析显示,患者及其携带者母亲出现异常单链条带。DNA测序表明,先证者该基因外显子1的第404位碱基胞嘧啶C被鸟嘌呤G颠换,致使EDA蛋白跨膜区第54位组氨酸突变成谷胺酰胺(H54Q),其母亲同一位置碱基呈现C～G杂合双峰。结论 本EDA家系中患者EDA1基因外显子1存在错义突变(404C→G),这可能是导致EDA发病的分子机制之一。     

X连锁少汗性外胚层发育不良一家系EDA基因的突变

目的检测一X连锁少汗性外胚层发育不良家系的EDA基因突变。方法收集患者及其父母资料,提取外周血DNA,采用PCR扩增EDA基因编码区的全部外显子及其侧翼序列,PCR产物测序,明确突变位点。以50例无关健康人作对照。结果该家系患者第7号外显子第895位鸟嘌呤G突变成腺嘌呤A,使EDA编码的蛋白第299位氨基酸密码子GGC变成AGC,导致正常的甘氨酸被丝氨酸所代替。其母亲在相同位置的碱基出现G-A双峰,显示为杂合性携带者,其父亲及50例无关健康对照未见此改变。结论G299S可能是导致该X性连锁少汗性外胚层发育不良家系临床表型的原因。     

有汗性外胚层发育不良一家系基因突变

目的 探讨有汗性外胚层发育不良家系的基因突变及突变类型，为建立本病的基因诊断与遗传咨询提供依据。方法 PCR及Sanger测序技术对有汗性外胚层发育不良家系先证者GJB6基因外显子进行突变鉴定，对可疑的变异位点， Sanger测序检测家系其他成员该位点变异情况。结果 基因检测结果表明，家系先症者GJB6基因错义突变c.31G〉A，该突变导致连接蛋白-30（connexin-30, CX-30）第11位氨基酸由甘氨酸变成精氨酸（p.G11R）。家系的患者均携带此变异，而家系表型正常的个体不携带此变异。结论 GJB6基因c.31G〉A（p.G11R）突变是该有汗性外胚层发育不良家系致病基因突变。     

X连锁少汗性外胚叶发育不良家系基因突变检测

目的:检测1例3月龄少汗性外胚叶发育不良男性患儿及其家族成员少汗性外胚叶发育不良(ED1)基因的突变.方法:提取家系成员白细胞中的DNA,设计引物特异扩增ED1基因的外显子及其侧翼区域并测序,与正常人的测序结果进行比较.结果:患儿ED1基因第466位碱基由胞嘧啶变为胸腺嘧啶,使翻译产物中相应的氨基酸由精氨酸变为半胱氨酸,即R156C.先证者母亲为杂合子,父亲未检测到突变.结论:R156C导致了X连锁少汗性外胚叶发育不良在该家系中的传递.     

X连锁少汗性外胚叶发育不良一家系ED1基因突变检测研究

目的:研究X连锁少汗性外胚叶发育不良一家系患者的临床表现及其致病原因.方法:在患者家系调查的基础上,收集家系中患者和正常人的血样,并采集正常对照血样100份,采取聚合酶链反应技术对ED1基因进行扩增,并对其产物进行测序.结果:该家系中所有的患者均表现为汗腺缺乏或减少,毛发稀少,全部或部分牙齿缺损.ED1基因第9号外显子存在1个22个碱基缺失突变.结论:该家系发病是由ED1基因突变所致,其发病的基因型和表型之间的关系有待于进一步研究.     

一遗传性对称性色素异常症家系ADAR基因突变检测

目的 探讨遗传性对称性色素异常症(DSH)一家系ADAR基因突变情况。方法 收集1个遗传性对称性色素异常症家系的外周血标本,采取PCR结合DNA直接测序的方法,检测了该家系中4例患者及3例表型正常者和150例无亲缘关系健康个体的ADAR基因突变情况。结果 该家系中患者存在ADAR基因上第2879位碱基腺嘌呤(A)转换成鸟嘌呤(G),使得ADAR基因的第10号外显子960位密码子由TAT突变成TGT,导致正常的酪氨酸(Tyr)被半胱氨酸(Cys)替代,而该家系的正常人对照及无关健康个体不存在此突变。结论 DSH家系中患者ADAR基因存在错义突变(2879 A→G),这可能是导致DSH发病的分子机制之一。     

伴丘疹性损害的先天性无毛症一例及其基因突变的研究

目的 研究1例伴丘疹性损害的先天性无毛症患者及其家系中无毛基因的突变情况。方法 取患者皮损进行组织病理检查;提取家系成员的基因组DNA,采用聚合酶链反应扩增无毛基因的全部编码序列并结合DNA直接测序方法,检测患者无毛基因的突变。结果 患者无毛基因存在两处杂合突变:第3外显子的1010位碱基由鸟嘌呤变为腺嘌呤,使第337位氨基酸由甘氨酸突变为天冬氨酸(G337D);第4外显子的1491位碱基由胞嘧啶变为胸腺嘧啶,使第498位氨基酸由谷氨酸突变为终止密码(Q498X)。而其父母及一弟该基因仅存在其中的一处杂合突变。结论 该患者无毛基因中G337D及Q498X两处突变可能使该基因无法编码正常的蛋白,为导致临床表现的特异突变。     

三个表皮松解性掌跖角化症家系KRT9基因突变的研究

目的 探讨表皮松解性掌跖角化症家系的KRT9基因突变与临床表现的关系。方法 PCR扩增KRT9基因编码氨基酸的7个外显子,对扩增产物进行变性高效液相色谱分析、DNA测序。结果 在所研究的3个EPPK家系中,发现KRT9基因第1外显子第497位核苷酸A缺失并插入GGCT,导致角蛋白9分子第166位酪氨酸缺失并插入色氨酸和亮氨酸,即Y166delinsWL。片段特异性PCR证实了该突变不是一个常见的多态性,而是国际中间纤维突变库(http://www.interfil.org)中未报道过的一种新突变。结论 KRT9基因497delAinsGGCT突变可能是部分中国人EPPK患者发病的遗传基础。     

多发性家族性毛发上皮瘤致病基因的确定

目的 对多发性家族性毛发上皮瘤一家系进行基因定位及候选基因突变检测。方法 共用18对覆盖9p21和16q12-q13的微卫星标记对一个多发性家族性毛发上皮瘤家系进行局部基因组扫描,并用Linkage软件进行两点参数连锁分析,最后PCR扩增CYLD1基因的17个编码外显子及其邻近剪接子并进行双向直接测序。结果 ①两点参数连锁分析在常染色体显性遗传模式下,外显率为99.9%、基因频率0.00001时在D16S3068位点处得出LOD值=3.31(θ=0.00),排除与9号染色体连锁;②突变分析在CYLD1基因第18号外显子出现连续的4个碱基缺失,即c.2355-2358delCAGA。结论 多发性家族性毛发上皮瘤存在着遗传异质性,本家系的致病基因位于16q12-q13,而不在9p21。     

A novel 22-bp deletion mutation in a Chinese family with X-linked hypohidrotic ectodermal dysplasia

X-linked hypohidrotic ectodermal dysplasia (XLHED) is the most common form of the ectodermal dysplasias characterized by an abnormal development of eccrine sweat glands, hair and teeth. Pathogenic mutations in the ED1 gene have been identified. In this family, a 22-bp deletion mutation of exon 8 in the ED1 gene was found in the affected members but not in the healthy individuals and 100 unrelated controls. We add new variant to the knowledge of ED1 mutations in XLHED.     

A novel 7-bp deletion mutation in a Taiwanese family with X-linked hypohidrotic ectodermal dysplasia

Hypohidrotic ectodermal dysplasia (HED) is found worldwide with an estimated incidence of 1 per 100,000 births. X-linked hypohidrotic ectodermal dysplasia (XLHED, OMIM 305100) is the most common form of the ectodermal dysplasias (ED), a rare group of hereditary diseases characterized by abnormal development of eccrine sweat glands, hair, and teeth. Heterozygous carriers of XLHED often manifest minor or moderate degrees of hypotrichosis, hypodontia, and hypohidrosis. ED1, the gene for XLHED encodes ectodysplasin A, which is a new member of the tumour necrosis factor family. The majority of mutations in XLHED are missense mutations, but one-fifth are insertion/deletions. Here we report a novel 7-bp deletion mutation (nt1242-1248) in exon 9 of the ED1 gene that results in a frameshift and premature stop codon (PTC + 38 amino acids). Mutation analysis in families with XLHED allows for genetic counselling, prenatal diagnosis and confirmation of carrier status.     

两个遗传性对称性色素异常症家系的DSRAD基因剪切突变

目的研究两个遗传性对称性色素异常症(DSH)家系中的DSRAD基因突变情况。方法收集了2个遗传性对称性色素异常症家系的外周血标本,用聚合酶链反应(PCR)扩增DSRAD基因的全部外显子并测序,检测2个家系中的患者及正常人和100例无关正常人的DSRAD基因。结果家系1中所有患者的DSRAD基因第6号内含子与第7号外显子交界处检测到一新的c.2271-3AG剪切突变。家系2中所有患者的DSRAD基因第12号外显子与第12号内含子交界处检测到一新的c.3202+5GA剪切突变。2家系中的正常人及100例无关正常人未发现突变。结论 2个DSH家系患者均有DSRAD基因剪切部位突变,可能由此引起非正常的基因剪切,导致编码蛋白的结构和功能改变,致皮肤色素异常。     

Gene dosage analysis identifies large deletions of the FECH gene in 10% of families with erythropoietic protoporphyria

Erythropoietic protoporphyria (EPP) is an inherited cutaneous porphyria characterized by partial deficiency of ferrochelatase (FECH), accumulation of protoporphyrin IX in erythrocytes, skin, and liver, and acute photosensitivity. Genetic counseling in EPP requires identification of FECH mutations, but current sequencing-based procedures fail to detect mutations in about one in six families. We have used gene dosage analysis by quantitative PCR to identify large deletions of the FECH gene in 19 (58%) of 33 unrelated UK patients with EPP in whom mutations could not be detected by sequencing. Seven deletions were identified, six of which were previously unreported. Breakpoints were identified for six deletions (c.1-7887-IVS1+2425insTTCA; c.1-9629-IVS1+2437; IVS2-1987-IVS4+352del; c.768-IVS7+244del; IVS7+2784-IVS9+108del; IVS6+2350-TGA+95del). Five breakpoints were in intronic repeat sequences (AluSc, AluSq, AluSx, L1MC4). The remaining deletion (Del Ex3-4) is likely to be a large insertion-deletion. Combining quantitative PCR with routine sequencing increased the sensitivity of mutation detection in 189 unrelated UK patients with EPP from 83% (95% CI: 76-87%) to 93% (CI: 88-96%) (P=0.003). Our findings show that large deletions of the FECH gene are an important cause of EPP. Gene dosage analysis should be incorporated into routine procedures for mutation detection in EPP.     

Tyrosinase gene analysis in Japanese patients with oculocutaneous albinism

BACKGROUND: Oculocutaneous albinism (OCA) is a heterogeneous congenital disorder. Tyrosinase is a key enzyme in melanin biosynthesis, and tyrosinase gene mutations cause the OCA1 subtype. OBJECTIVE: This study was intended evaluate the frequency and details of tyrosinase gene mutations in Japanese OCA patients. PATIENTS AND METHODS: We examined nine non-consanguineous OCA families, sequenced the tyrosinase gene of the patients and also confirmed a splicing site mutation using exon trapping system. RESULTS: Tyrosinase gene mutations were identified in five out of nine OCA families (55%). IVS2-10deltt-7t-a was present in 3 out of 18 alleles in three families (16%), P310insC was present in three alleles in three families (16%) and R278X was found in three alleles (16%), including those in one heterozygous and one compound homozygous patient. G97V (290 G-T) was found in 1 out of 18 alleles, and we could not find G97V in the mutation database. We have added this mutation as 9th mutation of Japanese OCA1 patients. In 8 of 18 alleles, four families, no tyrosinase mutations were identified. They were presumed not to be OCA1, but other subtypes of OCA. Exon trapping system demonstrated IVS2-10deltt-7t-a mutation generated the abnormal splicing site, and inserted the codon 4 bases in mRNA level resulting in premature termination codon downstream. CONCLUSION: This study provided new information about OCA1 mutations, and highlights the requirement of broader detailed search to make precise diagnosis of OCA.     

一例Kindler综合征患者皮损超微结构及FERMT1基因突变分析

目的 检测1例Kindler综合征患者皮损超微结构改变以及FERMT1基因突变。方法 收集患者临床资料,取患处皮肤进行透射电镜检查明确其超微结构的变化。提取患者及其相关亲属外周血DNA,采用PCR扩增FERMT1基因编码区的全部外显子及其侧翼序列并测序。结果 患者皮损电镜检查显示致密板高度复制;基因检测发现患者FERMT1基因9号内含子剪切位点发生IVS9 + 1G > A纯合突变,父母为相应突变的杂合携带者,50例无关正常对照者未见该突变。结论 透射电镜可作为Kindler综合征患者确诊的辅助检查之一;FERMT1基因9号内含子剪切位点发生IVS9 + 1G > A纯合突变可能为引起该患者临床表现的病因。     

Mutations in the ED1 gene in Japanese families with X-linked hypohidrotic ectodermal dysplasia

X-linked hypohidrotic ectodermal dysplasia (XLHED; OMIM 305100) is characterized by sparse hair, abnormal teeth and decreased sweating as a result of abnormal development of the sweat glands. Mutations in the ED1 gene, which encodes ectodysplasin-A (EDA), are responsible for XLHED. Ectodysplasin-A, a ligand for the EDA receptor, plays an important role in epidermal morphogenesis. We identified ED1 mutations including three novel mutations by sequencing genomic DNAs from eight unrelated Japanese XLHED families. Data from all reported mutations revealed that codon 156 in the furin subdomain is the most frequent site of change in EDA.     

Haplotype analysis in determination of the heredity of erythropoietic protoporphyria among Swiss families

Defects in the human ferrochelatase gene lead to the hereditary disorder of erythropoietic protoporphyria. The clinical expression of this autosomal dominant disorder requires an allelic combination of a disabled mutant allele and a low-expressed nonmutant allele. Unlike most other erythropoietic protoporphyria populations, mutations identified among Swiss erythropoietic protoporphyria families to date have been relatively homogeneous. In this study, genotype analysis was conducted in seven Swiss erythropoietic protoporphyria families, three carrying mutation Q59X, two carrying mutation insT213, and two carrying mutation delTACAG(580-584). Three different haplotypes of five known intragenic single nucleotide polymorphisms, namely -251 A/G, IVS1-23C/T, 798 G/C, 921 A/G, and 1520C/T, were identified. Each haplotype was shared by families carrying an identical mutation in the ferrochelatase gene indicating a single mutation event for each of the three mutations. These mutations have been present in the Swiss erythropoietic protoporphyria population for a relatively long time as no common haplotypes of microsatellite markers flanking the ferrochelatase gene were found, except of two conserved regions, telomeric of the insT213 allele and centromeric of the delTACAG(580-584)allele, each with a size > 3 cM. Among the nonmutant ferrochelatase alleles, patients from six erythropoietic protoporphyria families shared a common haplotype [-251G; IVS1-23T] of the first two single nucleotide polymorphisms. An exception was the haplotype [-251 A; IVS1-23C] identified in the index patient of one erythropoietic protoporphyria family. These results supported the recent findings that the low expressed allele is tightly linked to a haplotype [-251G; IVS1-23T] of two intragenic single nucleotide polymorphisms in the ferrochelatase gene.     

Clinical, biochemical, and genetic study of 11 patients with erythropoietic protoporphyria including one with homozygous disease

OBJECTIVE: To study the mutations in the ferrochelatase gene (FECH) and the phenotypic expression of erythropoietic protoporphyria (EPP) in a group of Spanish patients. DESIGN: Case series. SETTING: University-based hospital. PATIENTS: Eleven unrelated patients with EPP and 19 asymptomatic relatives from 10 families. MAIN OUTCOMES MEASURES: Measurement of protoporphyrin concentration in red blood cells and feces by fluorometry and chromatography. Analysis of the mutations of the FECH gene by single-strand conformation analysis. Expression of mutations in Escherichia coli. RESULTS: FECH gene mutations were found in all 11 patients. Ten were heterozygous and carried the IVS3-48C low-expression allele. Three novel mutations were found: IVS4 + 1delG, 347-351delC, and 130_147dupl 18. One patient did not present the IVS3-48C polymorphism and was found to harbor a novel A185T missense mutation in both alleles. The familial study confirmed a recessive mode of inheritance of the disease. The A185T mutation showed a residual activity 4% of normal when expressed in E coli. This patient presented cutaneous photosensitivity similar to the heterozygous cases, but a higher protoporphyrin accumulation in erythrocytes, microcytic anemia, and early signs of liver engagement. FECH mutations were found in 10 healthy relatives, none of whom carried the low-expression allele. The frequency of the IVS3-48C allele among 180 nonporphyric Spanish individuals was 5.2%. CONCLUSIONS: These findings confirm, among a group of Spanish patients, that most cases of EPP result from the coinheritance of IVS3-48C and a mutation in the FECH gene, and also document the existence of patients with mutations in homozygosity that may present a more severe form of the disease.     

表型温和的1型神经纤维瘤病：5个家系基因突变分析

【摘要】 目的 检测表型温和的1型神经纤维瘤病（NF1）患者的基因突变。方法 2017年6月至2020年6月于上海市奉贤区皮肤病防治所皮肤科门诊收集5例表型温和、仅有皮损的NF1先证者及其家系成员,在家系调查的基础上,观察和记录NF1的临床表型,并利用二代靶向基因测序结合Sanger测序来检测和验证致病突变。结果 5例先证者都仅有皮损（包括咖啡斑、雀斑、神经纤维瘤）,无其他系统损害;5个家系先证者共发现5种突变,分别位于NF1基因的不同外显子中,包括1个大片段缺失突变（hg38：chr17：31327199-31335928 del 8 730 bp）、1个剪切突变（c.7970+1G>T）、1个插入突变（c.3011 _3012insTATG,p.N1004fs*）、1个缺失突变（c.1754_1757delTAAC, p.T586Vfs*18）和1个无义突变（c.C503G,p.S168X）,前3种是未经报道的新突变。结论 在5个先证者表型温和的NF1家系中检测出5种突变,鉴定出3种新突变,丰富了NF1的突变谱。