表皮松解性掌跖角化病一家系KRT9基因突变检测

目的：检测一表皮松解性掌跖角化病(epidermolytic palmoplantar keratoderma,EPPK)家系中患者及其家族成员的KRT9基因突变。方法：收集该EPPK家系先证者及其家族成员临床资料,提取他们及100例无亲缘关系的健康对照外周血DNA,PCR扩增KRT9基因编码区的全部外显子及其侧翼序列,对产物直接测序,同时进行突变点的功能预测。结果：该家系所有患者的KRT9基因1号外显子第482位碱基均发生错义突变c.482A>G(p.Asn161Ser)。家系中未患病者及100名正常对照中均未发现此突变。SIFT和Polyphen-2软件预测c.482A>G(p.Asn161Ser)突变为有害变异位点。结论：KRT9基因的突变c.482A>G(p.Asn161Ser)可能是导致该家系发生表皮松解性掌跖角化病的原因。     

表皮松解掌跖角化症KRT9基因突变的研究进展

表皮松解性掌跖角化症(EPPK)是一种通常由位于17q12染色体上KRT9突变导致的常染色体显性遗传性皮肤病。本文综述了目前为止,EPPK家系中KRT9突变的类型及特点。通常认为KRT9基因突变热区位于螺旋结构的杆状功能域1A区和2B区。随着EPPK家系病例的不断积累,在K9的头部也已检出突变位点,不再局限于螺旋结构杆状结构域。     

KRT9基因突变所致表皮松解性掌跖角化病1例

报告KRT9基因突变所致表皮松解性掌跖角化病1例.患者男,中国籍,32岁,手足角化性斑块30余年.皮肤科检查:双侧掌跖面可见对称性弥漫性角化斑块,皮肤粗糙增厚,呈灰黄色.皮损组织病理:表皮明显角化过度,颗粒层棘层增厚,皮突延长,颗粒细胞变性,考虑掌跖角化病.基因全外显子组测序结果:KRT9基因外显子检测出c.487C＞...     

弥漫性表皮松解性掌跖角化病两家系突变分析

目的: 检测弥漫性表皮松解性掌跖角化病两家系中KRT9基因的突变情况。方法: 收集各家系患者的临床资料,抽取家系患者、正常人及200名健康志愿者外周血并提取DNA,采用聚合酶链式反应(PCR)扩增KRT9基因全部外显子并进行sanger测序。结果:在两个家系所有患者的KRT9基因1号外显子均检测到c．487C＞T 错义突变(p．163Ｒ＞W),家族未患病成员以及200名正常对照中未发现此突变。家系1中先证者的女儿和祖父除了掌跖角化过度外还出现了先天性指节垫和先天性指曲屈畸形,而家系2中所有患者并未出现该症状。结论: KRT9基因的c．487C＞T 错义突变是导致这两个表皮松解性掌跖角化病家系的遗传学病因,同一突变在不同家系或同一个家系的不同个体之间的临床表型存在差异。     

表皮松解性掌跖角化症遗传学研究进展

表皮松解性掌跖角化症是一种以掌跖表皮过度角化为主要特征的先天性遗传病.本文阐述了角蛋白分子的结构、分类以及由角蛋白突变所引起的一些遗传性角蛋白病,总结了迄今所发现的导致表皮松解性掌跖角化症的21种不同的角蛋白9基因突变类型及蛋白改变,在各个种族或民族中开展的有关角蛋白基因突变的研究情况.     

表皮松解性掌跖角化病二家系基因突变检测

目的：检测表皮松解性掌跖角化病二家系患者致病基因。方法：收集二家系资料,提取二家系成员及100名（无亲缘关系）正常对照血样DNA,采取聚合酶链反应技术对KRT1、KRT9和KRT16基因进行扩增,并对其产物进行测序。结果：家系1先证者中检测到 KRT1基因突变c.598T>C（p.F200L）。家系2三例患者中检测到KRT9基因含杂合突变c.488G>A（p.R163Q）。而家系正常成员及家系外无亲缘关系的100名正常对照中均不存在以上突变。结论：本研究表皮松解性掌跖角化病二家系发病与KRT1、KRT9基因突变有关,且KRT1基因突变p.F200L为国内首次报道。     

弥漫性掌跖角皮症一家系6例报告

先证者(09号病例)女,38岁,因掌跖部皮肤增厚、发硬38年,每年冬季易发生皲裂而就诊.患者自出生后4个月左右,掌跖皮肤出现淡黄色角化增厚,开始以大小鱼际肌等摩擦部位明显,随年龄增长,皮损弥漫至整个掌跖面,皮肤增厚、粗糙也愈明显.     

Vohwinkel残毁性掌跖角皮症

报告1例Vohwinkel残毁性掌跖角皮症.患者男,50岁.掌跖增厚脱屑40余年,双手指挛缩10年.体格检查:双掌跖角化增厚,双手除拇指外其余各指可见环形缩窄和挛缩,双足多趾离断.各指(趾)甲板正常.X线检查:双手指骨弯曲变形,部分趾骨破坏消失.诊断为残毁性掌跖角皮症.该例患者不伴有听力异常和鱼鳞病,无阳性家族史.     

残毁性掌跖角皮症1例

患者女,38岁。双掌跖皮肤弥漫增生肥厚、双手(足)小指(趾)逐渐环缩35年。查体见双掌跖皮肤弥漫增生肥厚,双足小趾脱落,双手小指第一关节处缩窄呈圆环形深沟,收缩环远端指头红肿呈球状,右手小指疼痛明显,并伴有缩窄环处糜烂、渗出、结痂。诊断为残毁性掌跖角皮症。予清热解毒、化瘀通络类中药口服,消炎止痛膏外敷治疗。1周后疼痛明显缓解,在随访中。     

A novel mutation of keratin 9 in a large Chinese family with epidermolytic palmoplantar keratoderma

BACKGROUND: Epidermolytic palmoplantar keratoderma (EPPK) is an autosomal dominant inherited skin disorder characterized by diffuse yellow thickening of the skin of the palms and soles, sharply bordered with erythematous margins. Histologically and ultrastructurally, EPPK presents cytolysis of keratinocytes and abnormal aggregation of tonofilaments in the suprabasal layers of the epidermis. To date, 15 different mutations of the keratin 9 gene (KRT9) have been demonstrated to cause most cases of EPPK. OBJECTIVES: To identify the KRT9 mutation in a large Chinese family with EPPK. METHODS: Denaturing high-performance liquid chromatography (DHPLC), DNA sequencing and allele-specific polymerase chain reaction (AS-PCR) were used to screen exon 1 of the KRT9 gene for sequence variations. RESULTS: The DHPLC elution profiles of the DNA fragments amplified from the affected samples differed from those obtained from unaffected individuals, indicating that a sequence variation existed within the analysed fragment of KRT9. DNA sequencing revealed a novel insertion-deletion mutation in the exon 1 of KRT9, 497delAinsGGCT, resulting in the change of tyrosine(166) to tryptophan and leucine (Y166delinsWL). AS-PCR confirmed the mutation was not a common polymorphism. CONCLUSIONS: The results suggest the molecular basis of EPPK in this Chinese family and provide further evidence that mutations in the helix initiation motif of keratin 9 underlie Chinese EPPK.     

Keratin-9 gene mutation in a family with epidermolytic palmoplantar keratoderma

BACKGROUND: Epidermolytic palmoplantar keratoderma is an autosomal dominant inherited disorder of keratinization. METHODS: We studied five members of a Jewish family with epidermolytic palmoplantar keratoderma. Genomic DNA was extracted from leucocytes, and exon 1 of the keratin 9 gene was amplified using polymerase chain reaction techniques. RESULTS: The mutation was found in exon 1 of the keratin 9 gene in codon 160. CONCLUSIONS: Like most of the other families with clinical features of epidermolytic palmoplantar keratoderma the mutation is found in exon 1 of the keratin 9 gene.     

A novel mutation of keratin 9 gene (R162P) in a Japanese family with epidermolytic palmoplantar keratoderma

Epidermolytic palmoplantar keratoderma (EPPK) is an autosomal dominant inherited skin disorder characterized by hyperkeratosis of the skin over the palms and soles. Mutations in keratin 9 gene (KRT9) have been demonstrated in EPPK. In this study, we screened a Japanese family with EPPK for KRT9 mutation by polymerase chain reaction amplification of genomic sequences, followed by heteroduplex analysis and direct nucleotide sequencing. The mutation consisted of a G-to-C transversion at codon 162 in exon 1, which was located in the hot spot of the mutations that have been reported previously (R162Q and R162W). However, the amino acid substitution was proline for arginine (R162P) in the 1A rod domain, the highly conserved helix initiation motif of keratin 9. Our result illustrates the repertoire of KRT9 mutation underlying the occurrence of EPPK in a Japanese family and is an important contribution to the investigation of the genotype/phenotype correlation.     

A keratin 9 Gene mutation (Asn160Ser) in a Japanese patient with epidermolytic palmoplantar keratoderma

We described a 5-year-old Japanese girl with epidermolytic palmoplantar keratoderma and examined her for a keratin 9 gene mutation. Physical examination disclosed diffuse yellowish hyperkeratosis with an erythematous border limited strictly to the palms and soles. Histological examination revealed hyperkeratosis with vacuolar degeneration in the spinous and granular layers of the epidermis. Sequence analysis demonstrated an A to G transition at the middle position of codon 160 in the 1A domain of the keratin 9 gene. The amino acid at codon 160 was deduced to have changed from asparagine (Asn) to serine (Ser). This is the first case with an Asn160Ser mutation in a Japanese. The substitution of Ser for Asn at codon 160 of the keratin 9 gene is assumed to be fatal for keratin filament assembly regardless of race or ethnicity.     

Keratin 9 gene mutations in five Korean families with epidermolytic palmoplantar keratoderma

Epidermolytic palmoplantar keratoderma (EPPK) is an autosomal dominant disease characterized clinically by localized palmoplantar thickening and histopathologically by granular degeneration of the epidermis. Recent molecular biological studies have revealed that EPPK is caused by mutations of the keratin 9 gene in sequences mainly encoding the highly conserved 1 A rod domain. Here we demonstrate a novel mutation of N160H (position 8 of the 1 A domain) and two other previously reported mutations, R162W and N160S, in five unrelated Korean families with EPPK. The three-dimensional structure of the 1 A domain of the related vimentin intermediate filament protein chain is now known. Based on its likely similarity to the keratin 9 chain, we predict that inappropriate amino acid substitutions in position 10 of 1 A will likely interfere with coiled-coil dimer stability, and those in position 8 will interfere with tetramer stability. Accordingly, these mutations compromise the structural integrity of the keratin intermediate filaments leading to the pathology of EPPK.     

一个表皮松解性掌跖角化病家系的KRT1基因突变分析

目的 探讨一个中国汉族人表皮松解性掌跖角化病(EPPK)家系的角蛋白基因KRT1、KRT9、KRT10突变情况.方法 收集1个EPPK家系的临床资料,提取外周血DNA,通过PCR扩增角蛋白KRT1、KRT9、KRT10基因编码区的全部外显子及其侧翼序列并测序,以表型正常家系成员及50例健康人为正常对照.结果 发现家系内6例患者均存在KRT1基因错义突变c.1436T>C,导致第479位的异亮氨酸被苏氨酸取代(I479T),在家系中6例正常人及50例对照者未发现上述突变.结论 错义突变KRTI的c.1436T>C可能为导致该家系临床表型的主要原因.本例为国内首次发现的KRT1突变引起的EPPK家系.

Abstract：

Objective To analyze the mutations in keratin 1 (KRT1), KRT9 and KRT10 genes in a Chinese family with epidermolytic palmoplantar keratoderma (EPPK). Methods Clinical data were collected from a family with EPPK. Genomic DNA was extracted from the peripheral blood of 12 family members, including 6 patients and 6 unaffected members, as well as from 50 unrelated normal human controls. PCR was performed to amplify all the exons and flanking sequences of KRT1, KRT9 and KRT10 genes followed by DNA sequencing.Results A missense mutation C.1436T > C was found in the highly conserved helix termination motif of KRT1 gene of all the patients, resulting in a substitution of isoleucine by threonine at position 479 of the KRT1 protein. No mutation was found in the unaffected members or unrelated controls. Conclusions The missense mutation C.1436T > C in K.RT1 gene is likely to be the main cause of the phenotype of EPPK in this family.This is the first report of a pedigree with KRT1 gene mutation-induced EPPK in China.