Novel homozygous frameshift mutation of EVER1 gene in an epidermodysplasia verruciformis patient

Epidermodysplasia verruciformis (EV) is a rare genetic skin disease with an autosomal recessive trait, and the patients have susceptibility to a specific group of human papillomavirus genotypes. Recently germline mutations in EVER1/2 genes have been detected in EV patients with different ethnic origins. In this study, we have applied PCR, single-stranded conformational polymorphism analysis, and sequencing as well as restriction fragment length polymorphism analysis for identifying potential mutation(s) of EVER genes in an EV patient and in the parents of Pakistani origin. A novel homozygous frameshift mutation (T base deletion at nucleotide position 968 of DNA) has been detected in the EVER1 gene of the patient. The parents carried this mutated allele in a heterozygous form. This is the third report on the presence of EVER1 mutations in an EV patient, and this result supports better understanding, diagnosis, and genetic counseling of EV patients.     

A homozygous nonsense mutation in the EVER2 gene leads to epidermodysplasia verruciformis

Epidermodysplasia verruciformis (EV) is a genodermatosis with mainly autosomal recessive inheritance. Pathogenic mutations in two adjacent genes, EVER1 and EVER2, have recently been identified. In this study, we performed mutation detection for the EVER1 and EVER2 genes on samples from a Chinese patient with EV, who had consanguineous parents. A homozygous C-->T transition at nucleotide position 568 within exon 6 of the EVER2 gene was detected. The mutation led to a premature translation termination (R190X) and the predicted protein lacked 537 amino acids. This novel nonsense mutation is, to our knowledge, the first mutation reported in Chinese patients with EV.     

Treatment of a patient with epidermodysplasia verruciformis carrying a novel EVER2 mutation with imiquimod

Epidermodysplasia verruciformis (EV) is a rare disorder characterized by widespread human papillomavirus infection and malignant transformation. EV may be caused by mutations of the genes EVER1 or EVER2, which are located on the EV1 locus, 17q25. We describe a patient with EV and a novel homozygous gene mutation of EVER2 gene who was treated successfully with topical imiquimod.     

Epidermodysplasia Verruciformis in Lipoid Proteinosis: Case Report and Discussion of Pathophysiology

Lipoid proteinosis (LP) is a rare autosomal recessive genodermatosis caused by mutations in extracellular matrix protein 1 (ECM1) that involves deposition of basement membrane–like material in the skin and other organs. Epidermodysplasia verruciformis (EV) is also a rare autosomal recessive genodermatosis involving susceptibility to human papillomavirus (HPV) infections and squamous cell carcinoma, caused in most cases by homozygous mutations in EVER1 or EVER2. We describe a case of EV in a patient with LP and discuss the pathophysiology. A 3‐year‐old Lebanese girl presented with hoarseness, beaded papules along the eyelid margins, waxy papules and plaques on her head and neck, and lichenoid verrucous papules on the forearms and hands. Histopathology of the waxy papules exhibited deposition of periodic acid Schiff–positive basement membrane–like material in the superficial dermis, characteristic of LP. The verruca plana–like lesions exhibited acanthosis and enlarged keratinocytes with pale blue‐grey cytoplasm and a perinuclear halo, consistent with verrucae and EV. Polymerase chain reaction amplification and sequencing of ECM1, EVER1, and EVER2 demonstrated a homozygous point mutation, c.389C>T (p.Thr130Met), in exon 6 of ECM1 and a heterozygous point mutation, c.917 A>T (p.Asn306Ile), in exon 8 in EVER2, known to cause EV in homozygous patients. The homozygous point mutation c.389C>T in ECM1 may be a novel mutation causing LP. Verruca plana–like lesions seen in LP appear to represent a form of acquired EV. In this patient, a heterozygous mutation in EVER2 at c.917 A>T may also have conferred susceptibility to HPV infection.     

外显子测序联合体细胞突变检测发现汗孔角化症八个突变位点

目的:外显子测序联合体细胞突变检测发现新的汗孔角化症致病基因突变.方法:收集前期实验在已知基因上通过目标区域测序未发现突变的29例汗孔角化症患者的外周血DNA进行全外显子测序,并提取体细胞DNA进行Sanger测序.结果:通过全外显子测序,在3例患者外周血DNA中检出剪切位点突变,包含1个MVK基因上的新突变位点.通过...     

Autosomal Dominant Epidermodysplasia Verruciformis Lacking a Known EVER1 or EVER2 Mutation

Abstract:  Epidermodysplasia verruciformis is a rare genodermatosis characterized by abnormal susceptibility to infection with specific human papillomavirus serotypes. Epidermodysplasia verruciformis is a genetically heterogeneous disease, and autosomal recessive and X-linked inheritance patterns have been reported. Nonsense mutations in the genes EVER1 and EVER2 have been identified in over 75% of cases. We present epidermodysplasia verruciformis in a father and a son with typical histologic and clinical findings that occur in the absence of mutations in EVER1 or EVER2. Epidermodysplasia verruciformis in this father/son pair in a nonconsanguinous pedigree is consistent with autosomal dominant inheritance. This is the first report of autosomal dominant transmission of epidermodysplasia verruciformis, providing further evidence of the genetic heterogeneity of epidermodysplasia verruciformis.     

类脂质蛋白沉积症两家系调查及ECM1基因突变检测

目的:检测类脂质蛋白沉积症二家系中细胞外基质蛋白(ECM1)基因突变位点。方法:提取1号家系先证者及其母亲,2号家系先证者、父母、配偶及儿子外周血DNA。PCR技术扩增ECM1基因编码序列,采用一代Sanger法对PCR扩增产物进行测序。结果:1号家系先证者在7号外显子发现已知突变(纯合突变c.960GA),其母亲为杂合携带者;2号家系先证者为遗传复合体,是上述突变位点的杂合携带者,此外在3号外显子上存在1个插入突变c.142insC。结论:类脂质蛋白沉积症存在遗传异质性。     

Nonsense mutations in the hairless gene underlie APL in five families of Pakistani origin

BACKGROUND: Atrichia with papular lesions (APL) is a rare autosomal recessive form of inherited alopecia. Affected individuals present with a distinct pattern of total hair loss on the scalp, axilla and body shortly after birth and are essentially devoid of eyelashes and eyebrows. This form of hair loss is irreversible and the histology is consistent with an absence of mature hair follicles. In addition to total atrichia, APL patients also present with papules and follicular cysts filled with cornified material. Mutations in the Hairless (HR) gene have been shown to underlie APL. OBJECTIVE: Here, we studied five unrelated large Pakistani families with clinical manifestations of APL. METHODS: Based on previous reports of HR mutations in APL, we performed direct DNA sequencing analysis. RESULTS: DNA sequencing of the HR gene in APL patients revealed three novel nonsense mutations in five unrelated families. All affected individuals were homozygous for a nonsense mutation due to C-to-T transitions at different positions in the amino acid sequence. Two families carry the mutation Q323X (CAG-TAG) in exon 3, two families harbor the mutation Q502X (CAG-TAG) in exon 6, and one family had a mutation at R940X (CGA-TGA) in exon 14. Haplotype analysis revealed that all affected individuals of both APL1 and APL16 families were homozygous for the same haplotype, and likewise, the mutation in families APL2 and APL19 was on the same haplotype. CONCLUSIONS: We report three novel nonsense mutations in the HR gene in APL. Two of the newly identified mutations, Q323X and Q502X, were found to be shared between unrelated families and marker analysis confirmed an identical homozygous haplotype for APL1 and APL16, and for APL2 and APL19. These findings suggest that Q323X and Q502X did not arise independently, but instead appear to have been propagated in the population. Collectively, these findings contribute further evidence for the involvement of hairless mutations in papular atrichia.     

家族性良性天疱疮患者ATP2C1基因突变研究

目的 探讨3个家族性良性天疱疮家系和1例散发患者的ATP2C1基因突变。方法 采取家系中患病成员外周血,应用外周血细胞DNA抽提、PCR扩增和DNA直接测序等方法检测ATP2C1基因突变情况,用反向测序验证突变,用100例无血缘关系个体作正常人对照。结果 在2个家族性良性天疱疮家系和1例散发患者中发现3个未曾报道的错义突变。家系1第20外显子2048位碱基G→A,导致错义突变R619K;家系2第8外显子853位碱基A→C,导致错义突变T221P;散发患者第23外显子2323位碱基T→C,导致错义突变Y711H。家系中非患病成员和100例无血缘关系正常人均未发现这些改变。在1个家族性良性天疱疮家系未检测到基因突变。结论 发现家族性良性天疱疮3种新的ATP2C1基因突变位点。     

New mutations of Darier disease in Tunisian patients

Darier’s disease (DD, MIM 124200) also known as Darier-White disease and keratosis follicularis, is a rare autosomal dominant skin disorder characterized by warty papules and plaques in the seborrheic area (central trunk, flexures, scalp, and forehead). Pathogenic mutations in the ATP2A2 gene encoding the sarcoplasmic/endoplasmic reticulum Ca²⁺ ATPase (SERCA) 2 gene underlie the disease. In the present study, we performed genetic investigation of three unrelated Tunisian families affected by DD. Mutation screening was performed by direct sequencing of the coding region and exon/intron boundaries of the ATP2A2 gene. Patients in the 3 studied families exhibited classical DD phenotype. DD was associated with neurological and cardiac disorders in one family. Two novel mutations were identified: a missense mutation (R559Q) and a frameshift mutation (1713-1714 del 2A). Both pathogenic mutations are located in exon 13 of the ATP2A2 gene and affected the ATP-binding site of the SERCA2 protein. In one family, no mutation was found within the coding region and exon/intron boundaries of the ATP2A2 gene. Our findings provide further evidence for the genetic heterogeneity of DD in Tunisia and that most mutations involved in this disease are family specific.     

Novel mutations in two families with Darier's disease

BACKGROUND: Darier's disease (DD) is an autosomal dominant skin disorder characterized by abnormal keratinization and acantholysis. Deleterious mutations in the gene ATP2A2 which encodes SERCA2, a calcium pump of the sarco/endoplasmic reticulum underlie the disease. OBJECTIVE: To identify the genetic defect in two Jewish families of eastern-European ancestry with DD. METHODS: DNA was extracted from peripheral blood of six patients and three healthy members of the two families. Polymerase chain reaction (PCR) was carried out to amplify the exons and flanking intron boundaries of the ATP2A2 gene followed by direct sequencing. Restriction fragment analysis verified the presence or absence of the mutations. Results Two novel mutations were identified. A nonsense mutation, a change of C391 to T (R131X) in exon 5, was found in one family and a missense mutation, a change of A530 to C (Q177P) in the second. The mutations were not present in 50 healthy individuals of the same ethnic origin. Both pathogenic mutations are in codons that are located in a highly conserved cytoplasmic beta-strand domain which functions as the transduction site. CONCLUSION: The existence of two mutations in two Jewish families of the same ancestry might confirm the previously published reports that most mutations in that gene are private.     

A new mutation of the double-stranded RNA-specific adenosine deaminase gene in a family with dyschromatosis symmetrica hereditaria

BACKGROUND: Dyschromatosis symmetrica hereditaria (DSH) is a pigmentary genodermatosis characterized by a mixture of hyperpigmented and hypopigmented macules localized on the back of the extremities and caused by mutations in the double-stranded RNA-specific adenosine deaminase (DSRAD) gene. OBJECTIVE: To identify gene mutations of DSRAD in patients with DSH. METHODS: A Chinese pedigree of typical DSH was subjected to mutation detection in DSRAD. Direct sequencing of all PCR products of the whole coding regions of DSRAD was performed to identify the mutation. RESULTS: A missense mutation 2747G-->T in the DSRAD gene was found in the affected members but not in the healthy individuals in this family and in 50 unrelated controls. CONCLUSION: Our study found a novel missense mutation in exon 9 of the DSRAD gene. We add new variants to the knowledge of DSRAD mutations in DSH.     

A novel mutation of CYLD in a Chinese family with multiple familial trichoepithelioma

Background Trichoepithelioma is a benign cutaneous tumour that originates from hair follicles and occurs either as a sporadic non-familial or a multiple-familial type. Recently, several mutations in the cylindromatosis (CYLD) gene have been reported in multiple familial trichoepithelioma (MFT). Objectives To report a Chinese family of MFT and to explore the genetic mutation. Methods A Chinese pedigree of typical MFT was subjected to mutation detection in CYLD. Direct sequencing of all PCR products of the whole coding regions of CYLD gene was performed to identify the mutation. Results The c.1178-1179delCA (p.T393fs) mutation was found in CYLD gene in the affected members, but not in the healthy individuals in the family. Conclusion Our study found a novel mutation in exon 10 of CYLD gene.     

Novel mutations in DSG1 causing striate palmoplantar keratoderma

Background.  Striate palmoplantar keratoderma (SPPK) has been shown to be caused by mutations in at least three genes: DSG1 , DSP and KRT1 .
Methods.  Three families with nine affected members were assessed using a candidate gene-based screening approach.
Results.  In all three families, new heterozygous mutations were found in DSG1 .
Conclusion.  Direct sequencing of cDNA derived from affected skin in one patient failed to reveal a pathogenic mutation, suggesting that SPPK results from haploinsufficiency for DSG1.     

类脂质蛋白沉积症家系ECM1基因突变检测

[摘要] 目的 检测一类脂蛋白沉积症家系细胞外基质蛋白1（ECM1）基因的突变,并探讨中国类脂蛋白沉积症家系ECM1基因的突变特点。方法 PCR扩增家系成员ECM1基因的全部外显子,并行DNA测序。以100例无关正常人作对照。结果 先证者及其胞兄的ECM1基因第六外显子均检测出第658位碱基发生T G纯合性突变,使220位的半胱氨酸转变为甘氨酸（p.C220G）。其父母均为该突变的杂合性携带者,该突变在100例无关正常对照中未被检测出。结论 p.C220G为引起本家系临床症状的特异性突变。     

三例散发I型神经纤维瘤病NF1基因突变检测

目的：对3例I型神经纤维瘤病(neurofibromatosis type1, NF1)患者及其家系进行致病基因突变检测。方法：应用目标序列捕获高通量测序技术对3例I型神经纤维瘤病患者进行测序。患者检测出可疑突变类型后,应用多重连接探针扩增技术（multiplex ligation-dependent probe amplification, MLPA）及Sanger测序技术对患者及其家系成员进行突变位点验证。并采用SIFT、PolyPhen_2、Mutation Taster和GERP++软件对致病性不明的位点进行致病性预测。结果：3例I型神经纤维瘤病患者分别检测到1个NF1基因变异：NF1基因整体杂合缺失、c.4064delC和Exon14_36del。其中c.4064delC与Exon14_36del未见文献报道,为新发突变。结论：本研究中3例I型神经纤维瘤病患者中发现3个NF1基因突变,其中2个为新发突变,扩充了NF1基因突变位点。     

三例散发Ⅰ型神经纤维瘤病NF1基因突变检测

目的:对3例Ⅰ型神经纤维瘤病(neurofibromatosis type1,NF1)患者及其家系进行致病基因突变检测。方法:应用目标序列捕获高通量测序技术对3例Ⅰ型神经纤维瘤病患者进行测序。患者检测出可疑突变类型后,应用多重连接探针扩增技术(multiplex ligation-dependent probe amplification,MLPA)及Sanger测序技术对患者及其家系成员进行突变位点验证。并采用SIFT、PolyPhen_2、Mutation Taster和GERP++软件对致病性不明的位点进行致病性预测。结果:3例Ⅰ型神经纤维瘤病患者分别检测到1个NF1基因变异:NF1基因整体杂合缺失、c.4064delC和Exon14_36del。其中c.4064delC与Exon14_36del未见文献报道,为新发突变。结论:本研究中3例Ⅰ型神经纤维瘤病患者中发现3个NF1基因突变,其中2个为新发突变,扩充了NF1基因突变位点。     

Mutations in the hairless gene underlie APL in three families of Pakistani origin

BACKGROUND: Atrichia with papular lesions (APL) (OMIM#209500) is a rare autosomal recessively inherited form of irreversible alopecia characterized by papular lesions of keratin-filled cysts on various regions of the body. Males and females are equally affected and present with a distinct pattern of total hair loss on scalp, axilla and body. It begins shortly after birth with the development of hair loss, and patients are normally devoid of eyelashes and eyebrows. Mutations in the hairless (HR) gene have been previously shown to be responsible for APL. OBJECTIVE: In this study, we studied the molecular basis of APL in three unrelated families of Pakistani origin. METHOD: Molecular analysis of the HR genes was performed on genomic DNA from probands and family members. RESULTS: DNA sequencing of the HR gene in family A revealed a novel homozygous 2bp deletion in exon 6 leading to a frameshift and a downstream premature termination codon in exon 8 (1782-83delAG). In family B, we identified a novel homozygous deletion of a G nucleotide at the exon 15-intron 15 boundary, termed 3097delG. Family C carries a previously reported missense mutation consisting of an A-to-G transition at nucleotide 276 resulting in the mutation N970S in exon 14. CONCLUSION: Two mutations identified in this study are novel mutations in the HR gene and extend the body of evidence implicating the hairless gene family in the pathogenesis of human skin disorders. The one previously reported mutation suggests it may represent a recurrent mutation, or alternatively, an allele that is widely dispersed around the world.     

The sound of silence: autosomal recessive congenital ichthyosis caused by a synonymous mutation in ABCA12

Autosomal recessive congenital ichthyosis refers to a heterogeneous group of cornification disorders of major impact on patients’ life. The disease has been linked so far to mutations in 8 distinct genes. We report a consanguineous family of Arab Muslim origin with several members displaying a severe form of congenital ichthyosiform erythroderma. Using a panel of polymorphic microsatellite markers, we identified a region of homozygosity shared by all patients on 2q34, in a region harbouring the ABCA12 gene. Direct sequencing of genomic DNA derived from a patient failed to reveal any obviously pathogenic change in the coding sequence of this gene. In contrast, cDNA sequence analysis revealed the existence of a 163‐bp‐long deletion in exon 24, thus pointing to a splicing defect. Careful reanalysis of the genomic DNA sequence revealed apart from several known single‐nucleotide polymorphisms, a hitherto unreported homozygous synonymous mutation in exon 24 (c.3456G>A; p.S1152S), which was found to lead to the formation of a novel splicing acceptor site. Synonymous mutations have been shown to uncommonly cause inherited disorders in humans. Here, we present the first example of a congenital form of ichthyosis resulting from such a genetic defect.     

Novel keratin 5 and 14 gene mutations in patients with epidermolysis bullosa simplex from Poland

Mutation analysis in keratins 5/14 (K5/14) had been performed in five Polish families with epidermolysis bullosa simplex (EBS) to extend genotype-phenotype correlation and to add to the mutation database. All the patients had been clinically classified into two subtypes of EBS; Weber-Cockayne (EBS-WC) and Dowling-Meara (EBS-DM) as well as one case of EBS with mottled pigmentation (EBS-MP). DNA from patients and their family members was assessed for mutations in K5 or 14 using polymerase chain reaction amplification and subsequent direct sequencing. We identified four different missense mutations in K5 and one missense mutation in K14. Three of these are novel. Mutations associated EBS-DM resided in the highly conserved 20 amino acids end of the 1A domain in K5. Direct nucleotide sequencing of a case of EBS-MP revealed a heterozygous P25L mutation in K5. However, no genotype-phenotype correlation was identified in families with EBS-WC. The present study demonstrates the first series of molecular genetic data in EBS from Poland.