单纯型大疱性表皮松解症Weber-Cockayne亚型一家系角蛋白5基因突变的检测

鉴定单纯型大疱性表皮松解症Weber-Cockayne亚型一家系中的基因突变位点。方法:应用聚合酶链反应(PCR)及DNA直接测序的方法,检测患者角蛋白5(KRT5)及角蛋白14(KRT14)基因的全部编码序列;针对所发现的突变,以限制性内切酶片段长度多态性(RFLP)分析加以验证。结果:该家系患者存在KRT5基因突变:第2外显子第596位碱基由腺嘌呤突变为胞嘧啶,导致第199位氨基酸由赖氨酸变为苏氨酸(K199T),而正常对照无此替代。结论:KRT5K199T为导致此家系中患者临床表现的特异突变,此突变位点为国内外首次报道。     

单纯型大疱性表皮松解症Dowling-Meara亚型基因突变检测

目的探讨单纯型大疱性表皮松解症Dowling-Meara亚型(EBS-DM)的遗传学发病机制。方法报告1例单纯型大疱性表皮松解症Dowling-Meara亚型(EBS-DM)的家系,选择该家系中2例患者、1名正常人及50名无血缘关系者,扩增外周血基因组DNA中编码角蛋白14(K14)和角蛋白5(K5)的所有外显子,PCR产物进行序列分析。结果在此EBS-DM家系患者中,位于K14第1外显子的125位密码子由CGC突变CAC,导致精氨酸由组氨酸替代(R125H),而家系中正常人及与家系无关的50例正常人无此突变。结论该EBS-DM家系患者的K14第1外显子存在R125H突变。     

单纯型大疱性表皮松解症3个家系角蛋白14/角蛋白5基因突变研究

目的:检测单纯型大疱性表皮松解症(EBS)的基因突变情况,探讨EBS的基因型与表型的关系.方法:收集3个EBS家系的临床资料,提取外周血DNA、通过PCR扩增角蛋白KRT14和KRT5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:全部患者均存在KRT14或KRT5基因的错义...     

白色丘疹样大疱性表皮松解症1例

白色丘疹样大疱性表皮松解症是一种以皮肤黏膜起水疱为特点的遗传性皮肤病，属营养不良型表皮松解症的一种．临床较少见．现将我们所见1例报道如下。     

白色丘疹样营养不良型大疱性表皮松解症1家系调查

白色丘疹样营养不良型大疱性表皮松解症（Pasini Epidermolysis Bullosa）是一种少见的遗传性皮肤病，近日我科诊治1例，并调查了其家系的发病情况，报道如下。     

挪威疥合并单纯型大疱性表皮松解症及狼疮性肾炎一例

患者,女,39岁。全身红斑结痂伴痒半年,蛋白尿3周。既往背部四肢反复破溃28年。组织病理示：角化过度伴灶性角化不全,角层下见疥虫,棘层肥厚,皮屑镜检见疥虫。电子显微镜示：表皮细胞间细胞连接装置明显减少或缺如,细胞之间可见明显间隙,部分区域大疱形成。血红蛋白74 g/L,尿蛋白+++,ANA阳性,抗心磷脂抗体IgG 31.9 U。诊断：挪威疥;单纯型大疱性表皮松解症;狼疮性肾炎。     

PCR-DNA直接测序检测1例单纯型大疱性表皮松解症Weber-Cockayne亚型(WC-EBS)患者角蛋白K5基因点突变

单纯型大疱性表皮松解症（ＥＢＳ）是一组常染色体显性的遗传性疾病，研究表明本病存在角蛋白Ｋ５／Ｋ１４基因点突变。ＥＢＳ的各个亚型突变发生部位有一定差异，其中Ｗｅｂｅｒ－Ｃｏｃｋａｙｎｅ亚型（ＷＣ－ＥＢＳ）突变多位于Ｋ５／Ｋ１４的连接区Ｌ１－２。本研究设计了扩增Ｋ５基因Ｌ１－２区ＤＮＡ片段的引物，应用ＰＣＲ对－ＷＣ－ＥＢＳ家系的患者及未发病成员进行扩增。ＰＣＲ产物测序发现患者Ｋ５第３４６密码子发生了Ａ→Ｃ的碱基替换，导致色氨酸（ＴＡＴ）变成丝氨酸（ＴＣＴ），而未发病成员则未见有碱基突变。结果表明，通过ＰＣＲ结合ＤＮＡ直接测序不失为快速、准确检测基因突变的方法。此外，连接区在角蛋白结构中不如螺旋区重要，因而此区基因突变对角蛋白二聚体形成的影响不大，这与临床上ＷＣ－ＥＢＳ病情相对较轻是一致的。     

遗传性营养不良型大疱性表皮松解症1例

大疱性表皮松解症（DEB）是一组遗传性皮肤病，表现为皮肤和黏膜受轻微机械性损伤后或自动形成大疱或血疱。根椐临床、遗传方式及病理组织中大疱的位置，该组皮肤病分为表皮内型（单纯性）、交界性和营养不良性大疱性表皮松解症三类，其中营养不良型又分为显性遗传（RDEB）和隐性遗传（DDEB）两种亚型。我们遇到1例轻型隐性遗传营养不良型大疱性表皮松解症，现报道如下。     

先天性皮肤发育不全伴单纯型大疱性表皮松解症二例

例１男,８d,因双小腿皮肤缺损８d,胸腹部起水疱６d就诊。父母非近亲结婚,否认类似疾病家族史。体检：儿科系统检查无异常。皮肤科检查：胸、上腹部可见枣大、手掌大湿润创面,表皮脱失,周围有豆大水疱,Nikolsky征（±）;右小腿内侧有条状、左踝部有环状皮肤缺损,稍凹陷,表面有少许淡黄色结痂。四肢远端未见水疱。毛发及指、趾甲发育良好。临床拟诊：新生儿大疱原因待诊。入院后给予局部清洁,紫草油纱布换药。组织病理检查：左胫部皮肤缺损处：表皮缺失,少许纤维组织样结构覆表面;腹部水疱：表皮基底层液化,有表皮下水疱,真皮…     

单纯型大疱性表皮松解症同一家族26例

临床资料患者男,14岁。因双足底丘疹、丘疱疹、水疱、大疱反复发作13年加重1周,于2004年6月来我院就诊。该患者自1岁学走路起,双足底摩擦部位频繁出现绿豆大皮色丘疹,继而形成水疱、大疱,水疱一般不破溃,1周可自然消退且无瘢痕。曾于外院多次就诊。近2年来,病情反复发作,皮疹增多渐累及手部,尤其手指持笔和摩擦部位亦出现水疱、大疱,自然病程5天左右。近1周来,因军训走路过多,病情再次复发且症状加重,遂来我院就诊。体检:一般状况佳,系统检查未见异常。皮肤科情况:双足底可见10余个黄豆至甲大黄色丘疱疹、水疱及大疱,尼氏征阴性,趾甲及手部…     

The clinical spectrum of epidermolysis bullosa simplex

As part of the U.K. National Epidermolysis Bullosa Register, we have systematically recorded clinical information on 130 (77%) of the 168 known Scottish epidermolysis bullosa simplex (EBS) sufferers. Three subtypes of EBS were recognized: Dowling–Meara (EBS‐DM), Weber–Cockayne (EBS‐WC) and Köbner (EBS‐Kb), seen in 5%, 42% and 53% of patients, respectively. As there is considerable overlap between EBS‐WC and EBS‐Kb, with both phenotypes frequently seen within the same pedigree, EBS‐WC is best regarded as a milder variant of EBS‐Kb rather than a separate disorder. Improvement with age is common in all variants of EBS, but is not invariable. Pain due to acral blistering in EBS‐Kb/EBS‐WC has a more marked impact on life‐style than the blisters of EBS‐DM. Oral blistering, nail involvement and aplasia cutis congenita occur in all EBS subtypes and laryngeal involvement is a feature of EBS‐DM. Seasonal variation is not seen in EBS‐DM but is common in EBS‐Kb/EBS‐WC.     

A novel de novo mutation p.Ala428Asp in KRT5 gene as a cause of localized epidermolysis bullosa simplex

Epidermolysis bullosa is a group of inherited blistering skin diseases resulting in most cases from missense mutations in KRT5 and KRT14 genes encoding the basal epidermal keratins 5 and 14. Here, we present a patient diagnosed with a localized subtype of epidermolysis bullosa simplex caused by a heterozygous mutation p.Ala428Asp in the KRT5 gene, that has not been previously identified. Moreover, a bioinformatic analysis of the novel mutation was performed, showing changes in the interaction network between the proteins. Identification of novel mutations and genotype‐phenotype correlations allow to better understanding of underlying pathophysiologic bases and is important for genetic counselling, patients’ management, and disease course prediction.     

Molecular confirmation of the unique phenotype of epidermolysis bullosa simplex with mottled pigmentation

BACKGROUND: A distinctive subtype of epidermolysis bullosa simplex, with the additional feature of mottled pigmentation (EBS-MP), was initially characterized in a Swedish family in 1979, and seven further families have been reported. Features of EBS-MP that are observed in most affected patients include acral blistering early in childhood, mottled pigmentation distributed in a number of sites, focal punctate hyperkeratoses of the palms and soles, and dystrophic, thickened nails. The genetic basis of EBS-MP has been ascribed in five unrelated families to a heterozygous point mutation, P25L, in the non-helical V1 domain of K5. OBJECTIVES: We report a clinical, ultrastructural and molecular study of two of the earliest families to be clinically characterized as EBS-MP. METHODS: The P25L mutation was identified in all affected members of each of these families, bringing the total number of EBS-MP families with this mutation to seven. RESULTS: This unusual recurrent mutation may uniquely cause EBS-MP. CONCLUSIONS: While the exact molecular mechanisms by which this mutation causes epidermolysis, palmoplantar keratoderma and pigmentation remain elusive, we suggest possible molecular mechanisms through which the P25L substitution could cause this unusual phenotype.     

Atypical epidermolysis bullosa simplex with a missense keratin 14 mutation p.Arg125Cys

Epidermolysis bullosa (EB) is a group of hereditary autosomal dominant bullous diseases. EB is divided into four major phenotypes: intraepidermal EB (or EB simplex), junctional EB, dermolytic EB and mixed EB (Kindler syndrome). EB simplex is further divided into three subtypes: localized EB simplex, Dowling-Meara EB simplex and other generalized EB simplex. We report a 28-year-old man with EB simplex with a missense keratin 14 mutation p.Arg125Cys associated with clumping of keratin filaments and acantholysis in mainly the spinous cells and basal cells. Immunohistochemistry revealed that the broader expression of keratin 5 and 14 was observed in the epidermis, while the expression of keratin 1/10 was quite normal. Dysregulated expression of keratin 5/14 may hinder some functions or roles of keratin 1/10, namely filament assembly of keratin 1/10 in spinous cell integrity, although the expression of keratin 1/10 was not affected and this has not been demonstrated before.     

Generalized,severe epidermolysis bullosa simplex caused by a Keratin 5 p.E477K mutation

Epidermolysis bullosa simplex (EBS) is a skin fragility disorder resulting from mutations of structural proteins in the epidermis. We provide a brief report of long‐term survival and reproduction in a mother with EBS due to keratin 5 (KRT5) c.1429G > A (p.E477K) mutation, which causes a particularly severe form of the disease.     

Weber-Cockayne亚型单纯型大疱性表皮松解症一家系报告

目的:研究Weber-Cockayne亚型单纯型大疱性表皮松解症(EBS-WC)一家系的基因突变,并进行产前诊断。方法:应用PCR及DNA直接测序方法明确突变位点,针对所发现的突变以限制性内切酶片段长度多态性(RFLP)分析加以验证,在此基础上于妊娠24周时对从胎儿羊水所提取的DNA进行测序及酶切验证。结果:该家系患者存在角蛋白(keratin,KRT)5基因突变:第7外显子第1388位碱基由胸腺嘌呤突变为胞嘧啶,导致第463位氨基酸由亮氨酸变为脯氨酸(L463P)。50名健康对照者不存在此突变。羊水细胞DNA不存在此突变的胎儿,出生后未患大疱性表皮松解症。结论:KRT5第7外显子的突变是引起该家系临床症状的特异性突变。     

Identification of novel and known KRT5 and KRT14 mutations in 53 patients with epidermolysis bullosa simplex: correlation between genotype and phenotype

Background Basal epidermolysis bullosa simplex (EBS) is a hereditary skin blistering disorder resulting in most cases from missense mutations in the keratin 5 (KRT5) or keratin 14 (KRT14) genes. Objectives To identify the underlying mutations in different EBS subtypes and correlate genotype and phenotype. Methods Mutation analysis was performed in 53 patients with EBS and their families by direct sequencing of the KRT5 and KRT14 genes. Results We identified 39 different mutations, of which 15 have not been published previously. Three novel deletion/insertion mutations, among them one in‐frame duplication, were associated with the rare phenotype of EBS with mottled pigmentation. We identified for the first time a patient with compound heterozygosity for KRT5 mutations causing Dowling–Degos disease and EBS. Conclusions Identification of novel mutations and genotype–phenotype correlations in EBS allow improved understanding of disease pathogenesis as well as better patient management.     

A keratin 14 'knockout' mutation in recessive epidermolysis bullosa simplex resulting in less severe disease

Epidermolysis bullosa simplex (EBS) is a blistering skin disease caused in most cases by mis-sense mutations in genes encoding the basal epidermal keratin (K) 5 and K14. The inheritance is usually autosomal dominant and the mutant keratin proteins appear to exert a dominant negative effect on the keratin intermediate filament cytoskeleton in basal keratinocytes. We report a child with a homozygous K14 mutation resulting in the complete absence of K14 protein in the epidermis; remarkably, he only had mild to moderate disease. Electron microscopy of a skin biopsy showed a marked reduction in numbers of keratin intermediate filaments in the basal keratinocytes. Immunofluorescence microscopy using monoclonal antibody LL001 against K14 showed no staining, suggesting a functional knockout of K14. Sequence analysis of genomic DNA revealed a homozygous mutation in codon 31 of K14 that resulted in a premature stop codon further downstream in exon 1. The child's mother, who is unaffected by the disease, is heterozygous for the mutation. The consanguineous father was unaffected and unavailable for testing. The resulting mRNA is predicted to encode a protein of 116 amino acids, of which the first 30 are identical to the normal K14 sequence, and the remaining 86 residues are mis-sense sequence. Four previously reported cases of autosomal recessive EBS with functional knockout of K14 were severely affected by blistering, in contrast to our patient in whom the predicted protein has only the first 30 amino acids of K14 and is therefore the closest to a true knockout of K14 protein yet identified.     

Novel keratin 14 gene mutations in patients from Hungary with epidermolysis bullosa simplex

Mutations in genes keratin 5 (KRT5) and 14 (KRT14) encoding the basal type keratin intermediate filaments have been identified in epidermolysis bullosa simplex (EBS) families and are likely to cause skin fragility. Three novel keratin 14 mutations in cases from the Hungarian Epidermolysis Bullosa Centre are reported. In a 7-year-old boy with Dowling-Meara type EBS (DM-EBS), who had severe skin symptoms with extended herpetiform blisters, a novel amino acid substitution N123K in keratin 14 had been detected. A 26-year-old woman with mild DM-EBS with prominent palmoplantar hyperkeratosis and without active blister formation had a novel R125G mutation in keratin 14. In a 6-year-old girl, with Weber-Cockayne type EBS (WC-EBS) with palmoplantar blisters and moderate mental retardation, a novel V133L substitution was detected. Her pedigree showed autosomal dominant mode of inheritance; in the two other families, only the index patients were affected. The N123K and R125G mutations causing DM-EBS phenotypes are located within the helix initiation motif of the rod domain, whereas the very close V133L mutation underlying the WC-EBS phenotype is outside of this region. These novel amino acid substitutions provide further information for genotype-phenotype correlation in KRT14 mutations, and demonstrate the first molecular genetic data in EBS patients from Hungary.     

Laryngeal involvement in the Dowling-Meara variant of epidermolysis bullosa simplex with keratin mutations of severely disruptive potential

The clinical features of the Dowling-Meara variant of epidermolysis bullosa simplex (EBS-DM) can, in an infant, be indistinguishable from other severe forms of epidermolysis bullosa (EB). Two unrelated infants with no family history of skin disease are described who, within hours of birth, developed extensive blistering of skin and oral mucosae and who both subsequently developed hoarse cries. Despite this superficial resemblance to other forms of EB, electron microscopy revealed a basal cell rupture and keratin aggregates characteristic of EBS-DM in the skin of both infants and in the vocal cord epithelium of one. Molecular analysis confirmed the diagnosis by identification of mis-sense point mutations in basal cell keratin genes in both cases. One patient carries a point mutation in keratin 14 (converting arginine at position 125 to histidine) and the other has a novel point mutation in keratin 5 (converting serine at position 181 to proline). Hoarseness is not a well documented feature of EBS-DM and is usually associated with junctional EB. These two patients demonstrate that the presence of a hoarse cry in an infant affected by severe EB does not necessarily indicate a poor prognosis.