1
|
Fazelpour S, Deverapalli SC, Nguyen B. Skin cancer-associated genodermatoses in skin of color patients: a review. Arch Dermatol Res 2024; 316:282. [PMID: 38796611 DOI: 10.1007/s00403-024-03087-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 10/22/2023] [Accepted: 04/26/2024] [Indexed: 05/28/2024]
Abstract
Skin cancers are associated with a large number of genodermatoses. Existing knowledge and guidelines on the presentations of these genodermatoses focus disproportionately on White patients. Our goal is to identify notable characteristics in location, frequency, and severity of cutaneous findings along with the median age of skin cancers in skin-of-color (SOC) patients with skin-cancer-associated genodermatoses to improve diagnosis rates. We searched for genodermatoses on six databases. Each case report or case series was reviewed, including reports, published in English, containing adult patient descriptions. Duplicate manuscripts were removed using EndNote. The following case-level data were collected from the manuscripts: age, gender, patient country or region of origin, author country/continent of residence, skin cancer-related, and other key dermatologic features. 381 published articles, with a total of 578 SOC patients, met criteria for inclusion. SOC patients can present with fewer classic findings, such as a lower incidence of basal cell carcinomas (44%) in SOC Gorlin syndrome patients than palmar pits (66%) and mandibular cysts (66%). Differences between SOC populations were also noted, such as leukoplakia being more common in Asian dyskeratosis congenita patients (80%) in comparison to African dyskeratosis congenita patients (44%). SOC patients also have varying onset of skin cancer depending on the genodermatosis, from a median of 25 years of age in Rothmund-Thomson syndrome to 53 in Muir-Torre syndrome. In this review, SOC patients with genodermatoses can have varying presentations. Being cognizant of these characteristics may lead to earlier diagnosis and interventions to mitigate skin-cancer-related morbidity in SOC patients.
Collapse
Affiliation(s)
- Sherwin Fazelpour
- Boston University School of Medicine, 72 E Concord St, Boston, MA, 02118, USA.
| | | | - Bichchau Nguyen
- Tufts Medical Center, 800 Washington St, Boston, MA, 02111, USA
| |
Collapse
|
2
|
Oh KY, Hong SD, Yoon HJ. Adenoid Ameloblastoma Shares Clinical, Histologic, and Molecular Features With Dentinogenic Ghost Cell Tumor: The Histologic Spectrum of WNT Pathway-Altered Benign Odontogenic Tumors. Mod Pathol 2023; 36:100051. [PMID: 36788106 DOI: 10.1016/j.modpat.2022.100051] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/21/2022] [Accepted: 11/08/2022] [Indexed: 01/11/2023]
Abstract
An epithelial odontogenic tumor called adenoid ameloblastoma (AA) has recently been included in the new WHO classification. However, AA has considerable overlapping features with a preexisting entity, dentinogenic ghost cell tumor (DGCT). This study compared the clinical, histologic, and molecular characteristics of AA and DGCT. Eight cases of odontogenic tumors initially diagnosed as AA or DGCT were included in this study. Quantitative histologic analysis, β-catenin immunohistochemistry, and molecular profiling using next generation sequencing were performed. Additionally, accumulated clinical data of AA and DGCT were statistically analyzed. Nuclear β-catenin accumulation was detected in all cases in common, although the tumors studied histologically consisted of varying combinations of the AA-like phenotype, ghost cells, and dentinoid. However, CTNNB1 hotspot mutations were not found in any case. Instead, loss-of-function mutations in tumor suppressor genes involved in the WNT pathway, including the APC, SMURF1, and NEDD4L genes, were found regardless of histologic type. In addition, KRT13 mutations were detected in 2 cases with a high proportion of ghost cells. Finally, a literature analysis revealed clinical similarities between the previously reported cases of AA and DGCT. These findings suggest that from a clinical and molecular point of view, AA and DGCT represent a histologic spectrum of WNT pathway-altered benign odontogenic tumors rather than 2 distinct tumors. Moreover, previously unidentified keratin mutations may be associated with ghost cell formation found in specific types of odontogenic lesions.
Collapse
Affiliation(s)
- Kyu-Young Oh
- Department of Oral Pathology, College of Dentistry, Dankook University, Cheonan, Korea; Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Seong-Doo Hong
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Hye-Jung Yoon
- Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea.
| |
Collapse
|
3
|
Rossi S, Castiglia D, Pisaneschi E, Diociaiuti A, Stracuzzi A, Cesario C, Mariani R, Floriddia G, Zambruno G, Boldrini R, Abeni D, Novelli A, Alaggio R, El Hachem M. Immunofluorescence mapping, electron microscopy and genetics in the diagnosis and sub-classification of inherited epidermolysis bullosa: a single-centre retrospective comparative study of 87 cases with long-term follow-up. J Eur Acad Dermatol Venereol 2021; 35:1007-1016. [PMID: 33274474 DOI: 10.1111/jdv.17060] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Epidermolysis bullosa (EB) comprises a heterogeneous group of skin fragility disorders, classified in four major types based on skin cleavage level, i.e. EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB), Kindler EB, and in more than 30 subtypes defined by the combination of laboratory and clinical data, including disease course. OBJECTIVES Our aims were to address whether, in the age of genomics, electron microscopy (TEM) has still a role in diagnosing EB, and whether the genotype per se may be sufficient to sub-classify EB. METHODS A thoroughly characterized single-centre EB case series was retrospectively evaluated to compare the power of TEM with immunofluorescence mapping (IFM) in establishing the EB type, and the ability of TEM, IFM and genetics to predict selected EB subtypes, i.e. severe dominant EBS (DEBS), severe JEB, severe recessive DEB (RDEB) and DEB self-improving, using genetic and final diagnosis, respectively, as gold standard. RESULTS The series consisted of 87 patients, including 44 newborns, with a median follow-up of 54 months. Ninety-five mutations were identified in EB-associated genes, including 25 novel variants. Both IFM and TEM were diagnostic in about all cases of JEB (21/21 for both) and DEB (43/44 for IFM, 44/44 for TEM). TEM sensitivity was superior to IFM for EBS (19/20 vs. 16/19). As to EB subtyping, IFM performed better than genetics in identifying severe JEB cases due to laminin-332 defect (14/14 vs. 10/14) and severe RDEB (eight/nine vs. seven/nine). Genetics had no role in self-improving DEB diagnosis; it almost equalled TEM in predicting severe DEBS (eight/nine vs. nine/nine) and enabled to discriminate dominant from recessive non-severe DEB phenotypes and to identify special subtypes, e.g. DEBS with KLHL24 mutations. CONCLUSIONS Transmission electron microscopy remains relevant to the diagnosis of EBS. IFM and genetics are essential and complementary tools in the vast majority of EB cases.
Collapse
Affiliation(s)
- S Rossi
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - E Pisaneschi
- Laboratory of Medical Genetics, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - A Diociaiuti
- Dermatology Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - A Stracuzzi
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - C Cesario
- Laboratory of Medical Genetics, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - R Mariani
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - G Zambruno
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - R Boldrini
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - A Novelli
- Laboratory of Medical Genetics, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - R Alaggio
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - M El Hachem
- Dermatology Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| |
Collapse
|
4
|
Molecular Modeling of Pathogenic Mutations in the Keratin 1B Domain. Int J Mol Sci 2020; 21:ijms21186641. [PMID: 32927888 PMCID: PMC7555247 DOI: 10.3390/ijms21186641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/06/2020] [Accepted: 09/07/2020] [Indexed: 12/29/2022] Open
Abstract
Keratin intermediate filaments constitute the primary cytoskeletal component of epithelial cells. Numerous human disease phenotypes related to keratin mutation remain mechanistically elusive. Our recent crystal structures of the helix 1B heterotetramer from keratin 1/10 enabled further investigation of the effect of pathologic 1B domain mutations on keratin structure. We used our highest resolution keratin 1B structure as a template for homology-modeling the 1B heterotetramers of keratin 5/14 (associated with blistering skin disorders), keratin 8/18 (associated with liver disease), and keratin 74/28 (associated with hair disorder). Each structure was examined for the molecular alterations caused by incorporating pathogenic 1B keratin mutations. Structural modeling indicated keratin 1B mutations can harm the heterodimer interface (R265PK5, L311RK5, R211PK14, I150VK18), the tetramer interface (F231LK1, F274SK74), or higher-order interactions needed for mature filament formation (S233LK1, L311RK5, Q169EK8, H128LK18). The biochemical changes included altered hydrophobic and electrostatic interactions, and altered surface charge, hydrophobicity or contour. Together, these findings advance the genotype-structurotype-phenotype correlation for keratin-based human diseases.
Collapse
|
5
|
Bchetnia M, Allard JP, Boucher-Lafleur AM, Cruz Marino T, Dupéré A, Powell J, McCuaig C, Bernier MÈ, Laprise C. Severe epidermolysis bullosa simplex phenotype caused by codominant mutations p.Ile377Thr in keratin 14 and p.Gly138Glu in keratin 5. Exp Dermatol 2020; 29:961-969. [PMID: 32885477 DOI: 10.1111/exd.14189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 07/28/2020] [Accepted: 08/24/2020] [Indexed: 12/22/2022]
Abstract
Epidermolysis bullosa simplex (EBS) is a rare skin disease usually inherited in an autosomal dominant pattern. EBS is resulting from mutations in keratin 5 (KRT5) and keratin 14 (KRT14) genes encoding the keratins 5 and 14 proteins expressed in the keratinocytes of the basal layer of the epidermis. To date, seven pathogenic mutations have been reported to be responsible for EBS in the Canadian population from the province of Quebec: p.Pro25Leu, p.Leu150Pro, p.Met327Thr and p.Arg559X in KRT5; p.Arg125Ser, p.Ile377Thr and p.Ile412Phe in KRT14. Here, we present a novel French-Canadian patient diagnosed with EBS confined to the soles but presenting a severe complication form including blisters, hyperkeratosis, skin erosions and toenail abnormalities. Mutation screening was performed by direct sequencing of the entire coding regions of KRT5 and KRT14 genes and revealed the previously reported missense heterozygous mutation c. 1130T > C in KRT14 (p.Ile377Thr). Furthermore, this patient is carrying a second mutation in KRT5, c.413G > A (p.Gly138Glu), which has been linked to an increased risk of basal cell carcinoma in the literature. We suspect an impact of the p.Gly138Glu variant on the EBS phenotype severity of the studied patient. The pathogenicity and consequences of both genetic variations were simulated by in silico tools.
Collapse
Affiliation(s)
- Mbarka Bchetnia
- Centre intersectoriel en santé durable, Département des sciences fondamentales, Université du Québec à Chicoutimi (UQAC), Saguenay, QC, Canada
| | - Jean-Pascal Allard
- Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Saguenay, QC, Canada
| | - Anne-Marie Boucher-Lafleur
- Centre intersectoriel en santé durable, Département des sciences fondamentales, Université du Québec à Chicoutimi (UQAC), Saguenay, QC, Canada
| | - Tania Cruz Marino
- Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Saguenay, QC, Canada
| | - Audrey Dupéré
- Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Saguenay, QC, Canada
| | - Julie Powell
- Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC, Canada
| | - Catherine McCuaig
- Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, QC, Canada
| | - Marie-Ève Bernier
- Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Saguenay, QC, Canada
| | - Catherine Laprise
- Centre intersectoriel en santé durable, Département des sciences fondamentales, Université du Québec à Chicoutimi (UQAC), Saguenay, QC, Canada.,Centre intégré universitaire de santé et de services sociaux du Saguenay-Lac-Saint-Jean, Saguenay, QC, Canada
| |
Collapse
|
6
|
Severe Generalized Epidermolysis Bullosa Simplex in Two Hong Kong Children due to De Novo Variants in KRT14 and KRT5. Case Rep Pediatr 2020; 2020:4206348. [PMID: 32351751 PMCID: PMC7183525 DOI: 10.1155/2020/4206348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/19/2020] [Indexed: 11/18/2022] Open
Abstract
We report two Hong Kong children with severe generalized epidermolysis bullosa simplex (EBS), the most severe form of EBS, without a family history of EBS. EBS is a rare genodermatosis usually inherited in an autosomal dominant fashion although rare autosomal recessive cases have been reported. Genetic studies in these patients showed that the first case was due to a novel de novo heterozygous variant, c.377T>G (NM_000526.5 (c.377T>G, p.Leu126Arg)) in the KRT14 gene and the second case was due to a rare de novo heterozygous variant c.527A>G (NM_000424.4, c.527A>G, p.Asn176Ser) in the KRT5 gene. To our knowledge, the c.377T>G variant in the KRT14 gene has not been previously reported, and the c.527A>G variant in the KRT5 gene is a rare cause of severe generalized EBS. In severe generalized EBS, infants exhibit severe symptoms at the onset; however, they tend to improve with time. A precise genetic diagnosis in these two cases aided in counseling the families concerning the prognosis in their affected children and the recurrence risk for future pregnancies.
Collapse
|
7
|
Zhang J, Ding Y, Li M, Yao Z, Zhuang Y. Known and novel mutations responsible for epidermolysis bullosa simplex cases in a Chinese population. Exp Ther Med 2019; 18:4661-4664. [PMID: 31772641 PMCID: PMC6862070 DOI: 10.3892/etm.2019.8130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 10/10/2019] [Indexed: 11/20/2022] Open
Abstract
Epidermolysis bullosa simplex, generalized severe (EBS-gen sev) is one of the major forms of EBS, caused by mutations of the keratin 5 (KRT5) or keratin 14 (KRT14). However, it is rarely reported in the Chinese population. The current study was performed on three unrelated Chinese families with five patients clinically suspicious for distinct stages of EBS. Mutation screening was performed by direct sequencing of the entire coding regions of KRT5 and KRT14 genes. A diagnosis of EBS-gen sev for patients in these three families was confirmed by revealing missense mutations c.373C>T (p.Arg125Cys), c.374G>T (p.Arg125Leu), and a novel frameshift mutation c.1231delG (p.Glu411Argfs*31) in KRT14. Considering two previously reported cases and the results of the current report, amino acid residue 125 is likely the most frequent hotspot of EBS-gen sev in the Chinese population. The current study further indicated that the symptoms of EBS-gen sev patients decline with age.
Collapse
Affiliation(s)
- Jia Zhang
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Yu Ding
- Dermatology Department, Mianyang Central Hospital, Mianyang, Sichuan 621000, P.R. China
| | - Ming Li
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Zhirong Yao
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Yin Zhuang
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| |
Collapse
|
8
|
Mariath LM, Santin JT, Frantz JA, Doriqui MJR, Kiszewski AE, Schuler-Faccini L. An overview of the genetic basis of epidermolysis bullosa in Brazil: discovery of novel and recurrent disease-causing variants. Clin Genet 2019; 96:189-198. [PMID: 31001817 DOI: 10.1111/cge.13555] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/01/2019] [Accepted: 04/17/2019] [Indexed: 12/23/2022]
Abstract
Epidermolysis bullosa (EB) is a genodermatosis that encompasses a group of clinically and genetically heterogeneous disorders classified in four major types: EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB) and Kindler syndrome. Our aim was to characterize recurrent and novel mutations associated to EB in a sample of Brazilian patients. Eighty-seven patients (25 EBS, 4 JEB and 58 DEB) were studied. We performed a next-generation sequencing-based multigene panel through ion torrent technology including 11 genes: KRT5, KRT14, PLEC, TGM5, LAMA3, LAMB3, LAMC2, COL17A1, ITGB4, COL7A1, and FERMT1. A total of 72 different pathogenic or likely pathogenic variants were identified, 32 of them are novel. The causal variant was detected in 82 patients (efficiency of 94.3%). Pathogenic variants in the residue 125 of KRT14 were identified in 32% of all EBS patients. In DEB patients, four COL7A1 variants were quite frequent, some of them clustered in specific Brazilian regions. Our study extends the spectrum of known mutations in EB and describes, for the first time, the genetic profile of EB patients from Brazil.
Collapse
Affiliation(s)
- Luiza M Mariath
- Postgraduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Juliana T Santin
- Postgraduate Program in Child and Adolescent Health, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Jeanine A Frantz
- Faculty of Medicine, Universidade Regional de Blumenau, Blumenau, Brazil.,Board of Directors, DEBRA Brasil (Epidermolysis Bullosa Research Association of Brazil), Blumenau, Brazil
| | - Maria J R Doriqui
- Section of Medical Genetics, Hospital Infantil Dr. Juvêncio Mattos, São Luís, Brazil
| | - Ana E Kiszewski
- Section of Dermatology, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil.,Section of Pediatric Dermatology, Hospital da Criança Santo Antônio, Irmandade da Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, Brazil
| | - Lavínia Schuler-Faccini
- Postgraduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Department of Genetics, Instituto Nacional de Ciência e Tecnologia de Genética Médica Populacional (INaGeMP), Porto Alegre, Brazil
| |
Collapse
|
9
|
Lalor L, Titeux M, Palisson F, Fuentes I, Yubero MJ, Tasanen K, Huilaja L, Has C, Tadini G, Haggstrom AN, Hovnanian A, Lucky AW. Epidermolysis bullosa simplex-generalized severe type due to keratin 5 p.Glu477Lys mutation: Genotype-phenotype correlation and in silico modeling analysis. Pediatr Dermatol 2019; 36:132-138. [PMID: 30515866 DOI: 10.1111/pde.13722] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND/OBJECTIVES Epidermolysis bullosa is a group of diseases caused by mutations in skin structural proteins. Availability of genetic sequencing makes identification of causative mutations easier, and genotype-phenotype description and correlation are important. We describe six patients with a keratin 5 mutation resulting in a glutamic acid to lysine substitution at position 477 (p.Glu477Lys) who have a distinctive, severe and sometimes fatal phenotype. We also perform in silico modeling to show protein structural changes resulting in instability. METHODS In this case series, we collected clinical data from six patients with this mutation identified from their national or local epidermolysis bullosa databases. We performed in silico modeling of the keratin 5-keratin 14 coil 2B complex using CCBuilder and rendered with Pymol (Schrodinger, LLC, New York, NY). RESULTS Features include aplasia cutis congenita, generalized blistering, palmoplantar keratoderma, onychodystrophy, airway and developmental abnormalities, and a distinctive reticulated skin pattern. Our in silico model of the keratin 5 p.Glu477Lys mutation predicts conformational change and modification of the surface charge of the keratin heterodimer, severely impairing filament stability. CONCLUSIONS Early recognition of the features of this genotype will improve care. In silico analysis of mutated keratin structures provides useful insights into structural instability.
Collapse
Affiliation(s)
- Leah Lalor
- Division of Pediatric Dermatology, MCW Department of Dermatology, Milwaukee, Wisconsin
| | - Matthias Titeux
- Laboratory of Genetic Skin Diseases, Inserm UMR1163, Imagine Institute, Paris, France.,University Paris Descartes - Sorbonne Paris Cite, Paris, France
| | - Francis Palisson
- Fundacion DEBRA Chile, Santiago, Chile.,Facultad de Medicina, Clinica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Ignacia Fuentes
- Fundacion DEBRA Chile, Santiago, Chile.,Centro de Genetica y Genomica, Facultad de Medicina, Clinica Alemana Universidad del Desarrollo, Santiago, Chile
| | - María J Yubero
- Fundacion DEBRA Chile, Santiago, Chile.,Facultad de Medicina, Clinica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Kaisa Tasanen
- Department of Dermatology, Pedego Research Unit, Oulu Center for Cell-Matrix Research, MRC Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Laura Huilaja
- Department of Dermatology, Pedego Research Unit, Oulu Center for Cell-Matrix Research, MRC Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Cristina Has
- Department of Dermatology, Medical Center - University of Freiburg, Freiburg, Germany
| | - Gianluca Tadini
- Pediatric Dermatology, Fondazione IRCC Ca'Granda - Ospedale Maggiore Policlinico di Milano, Milan, Italy
| | - Anita N Haggstrom
- Department of Dermatology and Pediatrics, Indiana University, Indianapolis, Indiana
| | - Alain Hovnanian
- Laboratory of Genetic Skin Diseases, Inserm UMR1163, Imagine Institute, Paris, France.,University Paris Descartes - Sorbonne Paris Cite, Paris, France
| | - Anne W Lucky
- Epidermolysis Bullosa Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| |
Collapse
|
10
|
Nanda A, Liu L, Al-Ajmi H, Al-Saleh QA, Al-Fadhli S, Anim JT, Ozoemena L, Mellerio JE, McGrath JA. Clinical subtypes and molecular basis of epidermolysis bullosa in Kuwait. Int J Dermatol 2018; 57:1058-1067. [PMID: 30011071 DOI: 10.1111/ijd.14099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 03/15/2018] [Accepted: 06/04/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND Epidermolysis bullosa (EB) is a clinically and genetically heterogeneous blistering skin disease, but in countries such as Kuwait, there are very limited data on the clinical and molecular pathology of EB. To improve understanding of EB in Kuwait, we report the experience of a local tertiary referral center over a 17.5 year period (January 2000-June 2017) in establishing clinical and molecular diagnoses. METHODS Review of hospital records and diagnostic reports. Individual cases were diagnosed by combinations of clinical assessment, skin biopsy (immunohistochemistry and transmission electron microscopy), Sanger sequencing of EB genes, and whole exome sequencing. RESULTS Fifty-four families with EB were registered with the clinic over this period, 41 of whom (84 patients) participated in diagnostic studies. Thirty-seven of these 41 families had consanguineous marriages; 34 had recessive forms of EB, while only seven had dominant subtypes. Recurrent mutations were observed in epidermal dystonin, transglutaminase 5, and type VII collagen. CONCLUSIONS The prevalence of EB in Kuwait is approximately three times that of internationally cited rates with an over-representation of autosomal recessive variants. Establishing the molecular basis of EB in Kuwait with accurate diagnostic subtyping provides a basis for determining healthcare requirements and improving patient management of EB.
Collapse
Affiliation(s)
- Arti Nanda
- As'ad Al-Hamad Dermatology Center, Salmiya, Kuwait
| | - Lu Liu
- National Diagnostic Epidermolysis Bullosa Laboratory, Viapath, St. Thomas' Hospital, London, UK
| | | | | | - Suad Al-Fadhli
- Department of Medical Laboratory Sciences, Faculty of Allied Health Sciences, Kuwait University, Safat, Kuwait
| | - John T Anim
- Department of Pathology, Faculty of Medicine, Kuwait University, Safat, Kuwait
- Ghana College of Physicians and Surgeons, Accra, Ghana
| | - Linda Ozoemena
- National Diagnostic Epidermolysis Bullosa Laboratory, Viapath, St. Thomas' Hospital, London, UK
| | - Jemima E Mellerio
- St. John's Institute of Dermatology, King's College London, Guy's Campus, London, UK
| | - John A McGrath
- St. John's Institute of Dermatology, King's College London, Guy's Campus, London, UK
| |
Collapse
|
11
|
Lucky AW, Dagaonkar N, Lammers K, Husami A, Kissell D, Zhang K. A comprehensive next-generation sequencing assay for the diagnosis of epidermolysis bullosa. Pediatr Dermatol 2018; 35:188-197. [PMID: 29334134 DOI: 10.1111/pde.13392] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Historically, diagnosis of epidermolysis bullosa has required skin biopsies for electron microscopy, direct immunofluorescence to determine which gene(s) to choose for genetic testing, or both. METHODS To avoid these invasive tests, we developed a high-throughput next-generation sequencing (NGS)-based diagnostic assay called EBSEQ that allows simultaneous detection of mutations in 21 genes with known roles in epidermolysis bullosa pathogenicity. Mutations are confirmed with traditional Sanger sequencing. RESULTS We present our EBSEQ assay and preliminary studies on the first 43 subjects tested. We identified 11 cases of epidermolysis bullosa simplex, five cases of junctional epidermolysis bullosa, 11 cases of dominant dystrophic epidermolysis bullosa, 15 cases of recessive dystrophic epidermolysis bullosa, and one case that remains without diagnosis. We also found an additional 52 variants of uncertain clinical significance in 17 of the 21 epidermolysis bullosa-associated genes tested. Three of the variants of uncertain clinical significance were also found in three other patients, for a total of 49 unique variants of uncertain clinical significance. We found the clinical sensitivity of the assay to be 75% to 98% and the analytical sensitivity to be 99% in identifying base substitutions and small deletions and duplications. Turnaround time was 3 to 6 weeks. CONCLUSIONS EBSEQ is a sensitive, relatively rapid, minimally invasive, comprehensive genetic assay for the diagnosis of epidermolysis bullosa.
Collapse
Affiliation(s)
- Anne W Lucky
- Division of General and Community Pediatrics and Cincinnati Children's Epidermolysis Bullosa Center, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Neha Dagaonkar
- Division of Human Genetics, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Karen Lammers
- Division of General and Community Pediatrics and Cincinnati Children's Epidermolysis Bullosa Center, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Ammar Husami
- Division of Human Genetics, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Diane Kissell
- Division of Human Genetics, Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Kejian Zhang
- Division of Human Genetics, Cincinnati Children's Hospital, Cincinnati, OH, USA
| |
Collapse
|
12
|
Zhang J, Yan M, Liang J, Li M, Yao Z. A novel KRT5 mutation associated with generalized severe epidermolysis bullosa simplex in a 2-year-old Chinese boy. Exp Ther Med 2016; 12:2823-2826. [PMID: 27882080 PMCID: PMC5103693 DOI: 10.3892/etm.2016.3717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 05/11/2016] [Indexed: 01/09/2023] Open
Abstract
Mutations in keratin 5 (KRT5) or KRT14 genes are responsible for the most severe form of epidermolysis bullosa simplex (EBS), which is EBS generalized severe (EBS-gen sev). To date, only four pathogenic mutations (p.Arg165Ser and p.Lys199Asn in KRT5; p.Arg125Cys and p.Arg125His in KRT14) have been reported to be responsible for EBS-gen sev in the Chinese population. In the present study, a 2-year-old Chinese boy was clinically suspected to suffer from EBS, and thus Sanger sequencing was performed in the extracted genomic DNA samples from the patient, his parents and 100 healthy controls. A novel de novo heterozygous missense mutation c.503A>G (p.Glu168Gly) located at the N-terminal end segment of the 1A domain in KRT5 was identified by molecular analysis. In silico analysis tools were used to predict the pathogenicity of the novel missense mutation. A diagnosis of EBS-gen sev was thus confirmed according to the clinical presentations and molecular results.
Collapse
Affiliation(s)
- Jia Zhang
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Ming Yan
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Jianying Liang
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Ming Li
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| | - Zhirong Yao
- Department of Dermatology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200092, P.R. China
| |
Collapse
|
13
|
Wakiguchi H, Hasegawa S, Maeba S, Kimura S, Ito S, Tateishi H, Ueda K, Ohga S. A Sporadic Neonatal Case of Epidermolysis Bullosa Simplex Generalized Intermediate with KRT5 and KRT14 Gene Mutations. AJP Rep 2016; 6:e108-11. [PMID: 26929861 PMCID: PMC4769090 DOI: 10.1055/s-0035-1570386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Background Epidermolysis bullosa simplex (EBS) is a rare genodermatosis resulting from multiple gene mutations, including KRT5 and KRT14. The clinical expression of the mechanobullous skin fragility disease has not been fully explained by the genotype. Case Description An 11-day-old Japanese newborn infant was hospitalized because of herpetiform skin blistering on the feet, which expanded systemically after birth. There was no evidence of virus infection. The biopsied skin lesion showed a blister on the lamina densa without keratin clumps, indicating a diagnosis of EBS-generalized intermediate. We punctured the blisters to remove the contents daily, which led to no exacerbation or infection. The genetic study determined that the patient carried double substitutions of KRT5 c.1424A > G (p.E475G) and KRT14 c.1237G > A (p.A413T). The asymptomatic mother and sister carried the KRT14 substitution, but the healthy father had no substitution of the KRT gene. Conclusion This is the first report of EBS-generalized intermediate in a newborn with de novo KRT5 gene mutation and KRT14 gene polymorphism, and no familial history of epidermolysis. Neonatal blistering due to EBS requires optimal skin management after excluding infectious and immunobullous diseases.
Collapse
Affiliation(s)
- Hiroyuki Wakiguchi
- Department of Pediatrics, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan
| | - Shunji Hasegawa
- Department of Pediatrics, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan
| | - Shinji Maeba
- Department of Pediatrics, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan
| | - Sasagu Kimura
- Department of Pediatrics, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan
| | - Satoko Ito
- Division of Pediatrics, JCHO Tokuyama Central Hospital, Shunan, Yamaguchi, Japan
| | - Hiroshi Tateishi
- Division of Pediatrics, JCHO Tokuyama Central Hospital, Shunan, Yamaguchi, Japan
| | - Kazuhiro Ueda
- Division of Pediatrics, Michigami Hospital, Hikari, Yamaguchi, Japan
| | - Shouichi Ohga
- Department of Pediatrics, Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, Japan
| |
Collapse
|
14
|
Topographical mapping of α- and β-keratins on developing chicken skin integuments: Functional interaction and evolutionary perspectives. Proc Natl Acad Sci U S A 2015; 112:E6770-9. [PMID: 26598683 DOI: 10.1073/pnas.1520566112] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Avian integumentary organs include feathers, scales, claws, and beaks. They cover the body surface and play various functions to help adapt birds to diverse environments. These keratinized structures are mainly composed of corneous materials made of α-keratins, which exist in all vertebrates, and β-keratins, which only exist in birds and reptiles. Here, members of the keratin gene families were used to study how gene family evolution contributes to novelty and adaptation, focusing on tissue morphogenesis. Using chicken as a model, we applied RNA-seq and in situ hybridization to map α- and β-keratin genes in various skin appendages at embryonic developmental stages. The data demonstrate that temporal and spatial α- and β-keratin expression is involved in establishing the diversity of skin appendage phenotypes. Embryonic feathers express a higher proportion of β-keratin genes than other skin regions. In feather filament morphogenesis, β-keratins show intricate complexity in diverse substructures of feather branches. To explore functional interactions, we used a retrovirus transgenic system to ectopically express mutant α- or antisense β-keratin forms. α- and β-keratins show mutual dependence and mutations in either keratin type results in disrupted keratin networks and failure to form proper feather branches. Our data suggest that combinations of α- and β-keratin genes contribute to the morphological and structural diversity of different avian skin appendages, with feather-β-keratins conferring more possible composites in building intrafeather architecture complexity, setting up a platform of morphological evolution of functional forms in feathers.
Collapse
|
15
|
Ng CS, Wu P, Fan WL, Yan J, Chen CK, Lai YT, Wu SM, Mao CT, Chen JJ, Lu MYJ, Ho MR, Widelitz RB, Chen CF, Chuong CM, Li WH. Genomic organization, transcriptomic analysis, and functional characterization of avian α- and β-keratins in diverse feather forms. Genome Biol Evol 2014; 6:2258-73. [PMID: 25152353 PMCID: PMC4202321 DOI: 10.1093/gbe/evu181] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Feathers are hallmark avian integument appendages, although they were also present on theropods. They are composed of flexible corneous materials made of α- and β-keratins, but their genomic organization and their functional roles in feathers have not been well studied. First, we made an exhaustive search of α- and β-keratin genes in the new chicken genome assembly (Galgal4). Then, using transcriptomic analysis, we studied α- and β-keratin gene expression patterns in five types of feather epidermis. The expression patterns of β-keratin genes were different in different feather types, whereas those of α-keratin genes were less variable. In addition, we obtained extensive α- and β-keratin mRNA in situ hybridization data, showing that α-keratins and β-keratins are preferentially expressed in different parts of the feather components. Together, our data suggest that feather morphological and structural diversity can largely be attributed to differential combinations of α- and β-keratin genes in different intrafeather regions and/or feather types from different body parts. The expression profiles provide new insights into the evolutionary origin and diversification of feathers. Finally, functional analysis using mutant chicken keratin forms based on those found in the human α-keratin mutation database led to abnormal phenotypes. This demonstrates that the chicken can be a convenient model for studying the molecular biology of human keratin-based diseases.
Collapse
Affiliation(s)
- Chen Siang Ng
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Ping Wu
- Department of Pathology, Keck School of Medicine, University of Southern California
| | - Wen-Lang Fan
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Jie Yan
- Department of Pathology, Keck School of Medicine, University of Southern California Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China
| | - Chih-Kuan Chen
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei, Taiwan
| | - Yu-Ting Lai
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Siao-Man Wu
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Chi-Tang Mao
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan Molecular Biology of Agricultural Sciences, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | - Jun-Jie Chen
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Mei-Yeh Jade Lu
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Meng-Ru Ho
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Randall B Widelitz
- Department of Pathology, Keck School of Medicine, University of Southern California
| | - Chih-Feng Chen
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan Center for the Integrative and Evolutionary Galliformes Genomics (iEGG Center), National Chung Hsing University, Taichung, Taiwan
| | - Cheng-Ming Chuong
- Department of Pathology, Keck School of Medicine, University of Southern California Center for the Integrative and Evolutionary Galliformes Genomics (iEGG Center), National Chung Hsing University, Taichung, Taiwan
| | - Wen-Hsiung Li
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan Department of Ecology and Evolution, University of Chicago
| |
Collapse
|
16
|
Banerjee S, Wu Q, Yu P, Qi M, Li C. In silico analysis of all point mutations on the 2B domain of K5/K14 causing epidermolysis bullosa simplex: a genotype–phenotype correlation. MOLECULAR BIOSYSTEMS 2014; 10:2567-77. [DOI: 10.1039/c4mb00138a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
17
|
Schumann H, Roth W, Has C, Volz A, Erfurt-Berge C, Magin TM, Bruckner-Tuderman L. Verrucous carcinoma in epidermolysis bullosa simplex is possibly associated with a novel mutation in the keratin 5 gene. Br J Dermatol 2012; 167:929-36. [PMID: 22639907 DOI: 10.1111/j.1365-2133.2012.11075.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Epidermolysis bullosa simplex (EBS) is mainly caused by mutations in the KRT5 and KRT14 genes. Squamous cell carcinoma (SCC) represents the second most frequent skin neoplasia with complex aetiology. The molecular events disrupting the orchestrated interplay between the cytoskeleton, cell adhesion molecules and signalling proteins are ill understood in SCC. We describe the molecular background and the unusual course of the disease in a patient with EBS Dowling-Meara, severe keratoderma and a massive verrucous carcinoma. Skin and tumour samples from the patient were analysed using light microscopy, immunohistochemistry and immunofluorescence mapping. Mutation analysis of the KRT5 and KRT14 genes identified the novel KRT5 mutation p.E477D. Invasive tumour areas were characterized by downregulation of keratins 5 and 14, reduced and irregular desmocollin-2 expression and increased expression of keratins 6, 16 and 17. Levels of Ki-67 were increased and levels of E-cadherin strongly reduced in the tumour tissue. In this case a novel KRT5 mutation led to increased fragility of keratinocytes. Desmosome and adherens junctions were destabilized, which may trigger keratinocyte-mediated inflammation, possibly via p120-catenin-dependent signalling, suggesting a link between a keratin mutation and SCC, which adds weight to the hypothesis that disturbance of the cytoskeleton represents a major cause in the appearance of the malignant phenotype. Some individuals with EBS may be at risk of developing secondary SCC.
Collapse
Affiliation(s)
- H Schumann
- Department of Dermatology, University Medical Center, Freiburg, Germany.
| | | | | | | | | | | | | |
Collapse
|
18
|
García M, Santiago JL, Terrón A, Hernández-Martín A, Vicente A, Fortuny C, De Lucas R, López JC, Cuadrado-Corrales N, Holguín A, Illera N, Duarte B, Sánchez-Jimeno C, Llames S, García E, Ayuso C, Martínez-Santamaría L, Castiglia D, De Luca N, Torrelo A, Mechan D, Baty D, Zambruno G, Escámez MJ, Del Río M. Two novel recessive mutations in KRT14 identified in a cohort of 21 Spanish families with epidermolysis bullosa simplex. Br J Dermatol 2012; 165:683-92. [PMID: 21623745 DOI: 10.1111/j.1365-2133.2011.10428.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Basal epidermolysis bullosa simplex (EBS) is a group of blistering genodermatoses mostly caused by mutations in the keratin genes, KRT5 and KRT14. Recessive mutations represent about 5% of all EBS mutations, being common and specific in populations with high consanguinity, where affected patients show severe phenotypes. OBJECTIVES To accomplish the first mutational analysis in patients of Spanish origin with EBS and to delineate a comprehensive genotype-phenotype correlation. METHODS Twenty-one EBS families were analysed. Immunofluorescence mapping at the dermoepidermal junction level was performed on skin biopsies from patients. Mutation screening of the entire coding sequences of KRT5 and KRT14 in genomic DNA was assessed by polymerase chain reaction and direct sequencing. RESULTS KRT5 or KRT14 causative mutations were identified in 18 of the 21 EBS families. A total of 14 different mutations were disclosed, of which 12 were dominant missense mutations and two truncating recessive mutations. Five of the 14 mutations were novel including three dominant in KRT5 (p.V186E, p.T321P and p.A428T) and two recessive in KRT14 (p.K116X and p.K250RfsX8). The two patients with EBS carrying homozygous recessive mutations were affected by severe phenotypes and belonged to consanguineous families. All five families with the EBS Dowling-Meara subtype carried recurrent mutations affecting the highly conserved ends of the α-helical rod domain of K5 and K14. The seven mutations associated with the localized EBS subtype were widely distributed along the KRT5 and KRT14 genes. Two families with mottled pigmentation carried the P25L mutation in KRT5, commonly associated with this subtype. CONCLUSIONS This study further confirms the genotype-phenotype correlation established for EBS in other ethnic groups, and is the first in a Mediterranean country (excluding Israel). This study adds two novel recessive mutations to the worldwide record to date, which includes a total of 14 mutations. As in previous reports, the recessive mutations resulted in a lack of keratin K14, giving rise to a generalized and severe presentation.
Collapse
Affiliation(s)
- M García
- Regenerative Medicine Unit, Epithelial Biomedicine Division, Basic Research Department, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Av. Complutense 22, 28040 Madrid, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Bolling MC, Lemmink HH, Jansen GHL, Jonkman MF. Mutations in KRT5 and KRT14 cause epidermolysis bullosa simplex in 75% of the patients. Br J Dermatol 2011; 164:637-44. [PMID: 21375516 DOI: 10.1111/j.1365-2133.2010.10146.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Epidermolysis bullosa simplex (EBS) is a mechanobullous genodermatosis that may be caused by mutations in the genes KRT5 and KRT14 encoding the basal epidermal keratins 5 (K5) and 14 (K14). Three main clinical subtypes of EBS exist, differing in onset, distribution and severity of skin blistering. Previous reports of KRT5 and KRT14 mutations suggest a correlation between the location of the mutation and the severity of the associated EBS phenotype. OBJECTIVES The prevalence of KRT5/KRT14 mutations and the genotype-phenotype correlation in the largest tissue-confirmed EBS population is investigated. METHODS KRT5 and KRT14 genomic DNA and cDNA sequences of 76 clinically well-defined unrelated EBS probands were amplified and then subjected to direct sequencing and product length analysis. Immunofluorescence microscopy on patients' skin biopsies with antibodies against K5 and K14 was performed to study protein expression. RESULTS In 57 of 76 (75%) probands 41 different KRT5 and KRT14 mutations were identified, of which 12 were novel. Mutations affecting the highly conserved helix boundary motifs of the rod domains of K5 and K14, and the K14 helix initiation motif in particular, were associated with the severest, EBS Dowling-Meara, phenotype. In 21 EBS probands (37%) the mutation was de novo. In 19 probands (25%) KRT5 or KRT14 mutations were excluded. CONCLUSIONS The phenotype-genotype correlation observed in this large EBS population underscores the importance of helix boundary motifs for keratin assembly. Only three-quarters of biopsy-confirmed EBS probands have KRT5 or KRT14 mutations, indicating genetic heterogeneity in EBS. Alternative gene candidates are discussed.
Collapse
Affiliation(s)
- M C Bolling
- Center for Blistering Diseases, Department of Dermatology, University Medical Center Groningen, the Netherlands.
| | | | | | | |
Collapse
|