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Abstract
Epidermolysis bullosa (EB) is an inherited, heterogeneous group of rare genetic dermatoses characterized by mucocutaneous fragility and blister formation, inducible by often minimal trauma. A broad phenotypic spectrum has been described, with potentially severe extracutaneous manifestations, morbidity and mortality. Over 30 subtypes are recognized, grouped into four major categories, based predominantly on the plane of cleavage within the skin and reflecting the underlying molecular abnormality: EB simplex, junctional EB, dystrophic EB and Kindler EB. The study of EB has led to seminal advances in our understanding of cutaneous biology. To date, pathogenetic mutations in 16 distinct genes have been implicated in EB, encoding proteins influencing cellular integrity and adhesion. Precise diagnosis is reliant on correlating clinical, electron microscopic and immunohistological features with mutational analyses. In the absence of curative treatment, multidisciplinary care is targeted towards minimizing the risk of blister formation, wound care, symptom relief and specific complications, the most feared of which - and also the leading cause of mortality - is squamous cell carcinoma. Preclinical advances in cell-based, protein replacement and gene therapies are paving the way for clinical successes with gene correction, raising hopes amongst patients and clinicians worldwide.
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2
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Bei M. Molecular genetics of ameloblast cell lineage. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2009; 312B:437-44. [PMID: 19090561 DOI: 10.1002/jez.b.21261] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Late tooth morphogenesis is characterized by a series of events that determine crown morphogenesis and the histodifferentiation of epithelial cells into enamel-secreting ameloblasts and of mesenchymal cells into dentin-secreting odontoblasts. Functional ameloblasts are tall, columnar, polarized cells that synthesize and secrete a number of enamel-specific proteins. After depositing the full thickness of enamel matrix, ameloblasts shrink in size and regulate enamel maturation. Amelogenesis imperfecta (AI) is a heterogeneous group of inherited defects in enamel formation. Clinically, AI presents as a spectrum of enamel malformations that are categorized as hypoplastic, hypocalcified, or hypomaturation types, based upon the thickness and hardness of the enamel. The different types of AI are inherited, either as X-linked, autosomal-dominant, or autosomal-recessive traits. Recently, several gene mutations have been identified to cause the subtypes of AI. How these genes, however, coordinate their function to control amelogenesis is not understood. In this review, we discuss the role of genes that play definitive role on the determination of ameloblast cell fate and life cycle based on studies in transgenic animals.
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Affiliation(s)
- Marianna Bei
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA.
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Epidermolysis bullosa hereditaria. Monatsschr Kinderheilkd 2008. [DOI: 10.1007/s00112-007-1663-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Sampaio MCDA, Oliveira ZNPD, Miguelez J. Diagnóstico pré-natal das genodermatoses. An Bras Dermatol 2007. [DOI: 10.1590/s0365-05962007000400009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
O diagnóstico pré-natal está indicado para algumas genodermatoses graves, como a epidermólise bolhosa distrófica recessiva e a epidermólise bolhosa juncional. A biópsia de pele fetal foi introduzida em 1980, mas não pode ser realizada antes da 15a semana de gestação. A análise do DNA fetal é método preciso e pode ser realizado mais precocemente na gestação. No entanto, deve-se conhecer a base molecular da genodermatose, e é essencial determinar a mutação e/ou marcadores informativos nas famílias com criança previamente afetada. O DNA fetal pode ser obtido pela biópsia da vilosidade coriônica ou amniocentese. O diagnóstico genético pré-implantação tem surgido como alternativa que dispensa a interrupção da gestação. Essa técnica, que envolve fertilização in vitro e teste genético do embrião. vem sendo realizada para genodermatoses em poucos centros de referência. A ultra-sonografia é exame não invasivo, mas tem uso limitado no diagnóstico pré-natal de genodermatoses. A ultrasonografia tridimensional geralmente estabelece o diagnóstico tardiamente na gestação, e há apenas relatos anedóticos de diagnóstico pré-natal de genodermatoses usando esse método.
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Liu L, Choy YS, Wessagowit V, Ozoemena L, Dopping-Hepenstal PJC, Fassihi H, McGrath JA. Single nucleotide polymorphism in a commonly utilized LAMB3 primer sequence: implications for mutation detection and haplotype analysis in junctional epidermolysis bullosa. J Dermatol Sci 2006; 44:48-51. [PMID: 16814527 DOI: 10.1016/j.jdermsci.2006.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Revised: 04/19/2006] [Accepted: 05/22/2006] [Indexed: 11/16/2022]
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Fassihi H, Eady RAJ, Mellerio JE, Ashton GHS, Dopping-Hepenstal PJC, Denyer JE, Nicolaides KH, Rodeck CH, McGrath JA. Prenatal diagnosis for severe inherited skin disorders: 25 years' experience. Br J Dermatol 2005; 154:106-13. [PMID: 16403102 DOI: 10.1111/j.1365-2133.2005.07012.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Over the last 25 years there have been major advances in methods for prenatal testing of inherited skin disorders. Since 1979, our group at the St John's Institute of Dermatology has performed 269 prenatal diagnoses, using a variety of approaches, including fetal skin biopsy (FSB), chorionic villus sampling (CVS) and preimplantation genetic diagnosis (PGD). OBJECTIVES This study was designed to review the clinical indications, testing procedures and laboratory analyses for all prenatal tests conducted at St John's over this period. METHODS FSBs were examined for morphological and, when relevant or feasible, immunohistochemical abnormalities. The DNA-based tests involved screening by nucleotide sequencing, restriction enzyme digests or, in a few cases, by linkage analysis. Results Of the 269 tests, 191 were FSB, 76 were CVS and two were PGD. The major indications for FSB were epidermolysis bullosa (EB) (138 cases, including 88 junctional and 48 dystrophic), ichthyoses (37 cases, including 22 tests for harlequin ichthyosis) and oculocutaneous albinism (12 cases). Of the CVS procedures, 75 were for EB (40 junctional, 35 dystrophic) and one was for the EEC (ectrodactyly, ectodermal dysplasia, clefting) syndrome. Both of the PGD procedures were for the skin fragility-ectodermal dysplasia syndrome. All tests provided accurate diagnoses and the fetal loss rate was approximately 1% for both FSB and CVS. CONCLUSIONS The development of prenatal testing has proved to be of great benefit for individuals or couples at risk of having children with severe inherited skin disorders and, in the absence of a cure, prenatal testing along with appropriate counselling has become an important translational benefit of basic research and an integral part of clinical management.
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Affiliation(s)
- H Fassihi
- Genetic Skin Disease Group, St. John's Institute of Dermatology, GKT Medical School, St. Thomas' Hospital, Kings' College London, London, UK
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8
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Abstract
Late tooth morphogenesis is characterized by a series of events that determine cusp morphogenesis and the histodifferentiation of epithelial cells into enamel-secreting ameloblasts. Mice lacking the homeobox gene Msx2 exhibit defects in cusp morphogenesis and in the process of amelogenesis. To better understand the basis of the Msx2 mutant tooth defects, we have investigated the function of Msx2 during late stages of tooth morphogenesis. Cusp formation is thought to be under the control of the enamel knot, which has been proposed to act as an organizing center during this process (Vaahtokari et al. [ 1996] Mech. Dev. 54:39-43). Bone morphogenetic protein-4 (BMP4) has been suggested to mediate termination of enamel knot signaling by means of regulation of programmed cell death (Jernvall et al. [ 1998] Development 125:161-169). Here, we show that Bmp4 expression in the enamel knot is Msx2-dependent. We further show that during amelogenesis Msx2 is required for the expression of the extracellular matrix gene Laminin 5 alpha 3, which is known to play an essential role during ameloblast differentiation. This result thus provides a paradigm for understanding how transcription factors and extracellular matrix can be integrated into a developmental pathway controlling cell differentiation.
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Affiliation(s)
- Marianna Bei
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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Fassihi H, Ashton GHS, Denyer J, Mellerio JE, Mason G, McGrath JA. Prenatal diagnosis of Herlitz junctional epidermolysis bullosa in nonidentical twins. Clin Exp Dermatol 2005; 30:180-2. [PMID: 15725250 DOI: 10.1111/j.1365-2230.2004.01704.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Advances in molecular diagnostics have led to the feasibility of DNA-based prenatal testing in families at risk for recurrence of severe forms of both dystrophic and junctional epidermolysis bullosa. In this report, we describe prenatal testing in a woman who previously had a child affected with Herlitz junctional epidermolysis bullosa. However, in her second pregnancy, she was found to have dichorionic diamniotic twins. DNA analysis of a pathogenic mutation and informative intragenic polymorphisms (LAMB3 gene) predicted one fetus to be affected and the other unaffected. Selective termination of the affected fetus was performed, and pregnancy with the unaffected fetus was continued, leading to full term delivery of a healthy girl with no skin blisters. This is the first reported case of DNA analysis in a twin pregnancy at risk of Herlitz junctional epidermolysis bullosa, with successful diagnosis and selective termination of one affected twin.
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Affiliation(s)
- H Fassihi
- Genetic Skin Disease Group, St John's Institute of Dermatology, The Guy's King's College and St Thomas' Hospital Medical School, London, UK
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Pfendner EG, Nakano A, Pulkkinen L, Christiano AM, Uitto J. Prenatal diagnosis for epidermolysis bullosa: a study of 144 consecutive pregnancies at risk. Prenat Diagn 2003; 23:447-56. [PMID: 12813757 DOI: 10.1002/pd.619] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Epidermolysis bullosa (EB) is a group of inherited disorders characterized by increased skin fragility, resulting in blisters and erosions after minor trauma. Mutations in 10 structural genes expressed in the cutaneous basement membrane zone have been reported. The DebRA Molecular Diagnostics Laboratory at Jefferson Medical College has performed 144 DNA-based prenatal diagnoses since 1993 in families at risk for recurrence of the most severe forms of EB, including the recessive dystrophic EB (RDEB), junctional EB (JEB), EB with pyloric atresia (EB-PA), and EB simplex (EBS). A mutation-detection strategy using either conformation-sensitive gel electrophoresis (CSGE) or denaturing high-performance liquid chromatography (dHPLC) scanning analysis, followed by nucleotide sequencing, was applied to most cases with DEB and to all JEB, EB-PA, and EBS families. For some RDEB families, linkage analysis was performed, either alone when the inheritance pattern was clear or in combination with one mutation. Among the 144 prenatal diagnoses, 63 were for RDEB, 69 for JEB, 6 for EB-PA, and 6 for EBS. Twenty-eight normal, 73 heterozygous carrier, and 28 affected RDEB, JEB, and EB-PA pregnancies were reported in these recessively inherited diseases. Two affected and four normal pregnancies were predicted in dominantly inherited EBS. Among the 144 pregnancies, 9 were terminated without confirmation, 13 cases were lost to follow-up, and 6 pregnancies are ongoing. There were 6 families with inconclusive results due either to recombination events between flanking markers, absence of informative markers for one allele, or lack of sample from the previously affected child. There were three discordant results, one that was explained by maternal contamination of the chorionic villus sample and two that were unresolved. Overall, the availability, relative ease, and over 98% success rate make molecular DNA-based prenatal diagnosis a viable option for EB families at risk.
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Affiliation(s)
- Ellen G Pfendner
- Department of Dermatology, Jefferson Medical College and The Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia 19107, USA
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11
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Uitto J, Pulkkinen L, Ringpfeil F. Progress in molecular genetics of heritable skin diseases: the paradigms of epidermolysis bullosa and pseudoxanthoma elasticum. J Investig Dermatol Symp Proc 2002; 7:6-16. [PMID: 12518787 DOI: 10.1046/j.1523-1747.2002.19637.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The 42nd Annual Symposium on the Biology of the Skin, entitled "The Genetics of Skin Disease", was held in Snowmass Village, Colorado, in July 1993. That meeting presented the opportunity to discuss how modern approaches to molecular genetics and molecular biology could be applied to understanding the mechanisms of skin diseases. The published proceedings of this meeting stated that "It is an opportune time to examine the genetics of skin disease" (Norris et al, 1994). Indeed, this meeting just caught the wave of early pioneering studies that have helped us to understand the molecular basis of a large number of genodermatoses. This overview presented in the 50th Annual Symposium on the biology of the skin, highlights the progress made in the molecular genetics of heritable skin diseases over the past decade.
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Affiliation(s)
- Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA.
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12
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Abstract
Human epidermis is a squamous stratified epithelium whose integrity relies on balanced processes of cell attachment, proliferation, and differentiation. In monogenic skin dermatoses, such as mecano-bullous diseases, or DNA repair deficiencies such as the xeroderma pigmentosum (XP), alterations of skin integrity may have devastating consequences as illustrated by the extremely high epidermal cancer proneness of XP patients. The lack of efficient pharmacological treatments, the easy accessibility of skin, and the possibility of long term culture and genetic manipulations ex vivo of epidermal keratinocytes, have encouraged approaches toward gene transfer and skin therapy prospects. We review here some of the human genetic disorders that exhibit major traits in skin, as well as requirements and difficulties inherent to approaches aimed at stable phenotypic correction.
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Affiliation(s)
- Thierry Magnaldo
- Laboratory of Genetic Instability and Cancer, CNRS UPR2169, André Lwoff Institute, 7 rue Guy Môquet, 94 801 Villejuif, France.
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13
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Abstract
O estudo das alterações moleculares das epidermólises bolhosas tem contribuído para que se compreenda melhor essas enfermidades. Na epidermólise bolhosa simples a maioria dos casos está associada com alteração nas citoqueratinas basais 5 (gen KRT5) e 14 (gen KRT14), o que modifica o citoesqueleto na camada basal da epiderme, levando à degeneração dessa camada, formando bolha intra-epidérmica. Mutações na plectina (gen PLEC1), componente da placa interna do hemidesmossoma, levam também à clivagem intra-epidérmica. Na epidermólise bolhosa juncional vários gens estão envolvidos, em decorrência da complexidade da zona da membrana basal, todos levando ao descolamento dos queratinócitos basais na lâmina lúcida, pela disfunção da aderência entre esses e a lâmina densa. Alterações na laminina 5 (gens LAMA3, LAMB3 e LAMC2), integrina alfa6beta4 (gens ITGA6 e ITGB4) e colágeno XVII (gen COL17A1) foram descritas. Por fim, na epidermólise bolhosa distrófica apenas um gen está mutado, alterando o colágeno VII (gen COL7A1), principal componente das fibrilas ancorantes, produzindo clivagem abaixo da lâmina densa, variando fenotipicamente de acordo com a conseqüência da mutação. Outra aplicação importante dessas informações refere-se ao diagnóstico pré-natal, com a perspectiva no futuro da terapia gênica.
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Jiang QJ, Izakovic J, Zenker M, Fartasch M, Meneguzzi G, Rascher W, Schneider H. Treatment of two patients with Herlitz junctional epidermolysis bullosa with artificial skin bioequivalents. J Pediatr 2002; 141:553-9. [PMID: 12378197 DOI: 10.1067/mpd.2002.127794] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To evaluate the effects of a treatment with artificial skin bioequivalents in Herlitz junctional epidermolysis bullosa (H-JEB). METHODS Two infants, both homozygous for the Herlitz mutation R635X in the LAMB3 gene, who had refractory anemia and hypoproteinemia as a result of a continuous loss of body fluids through multiple large erosions, were treated with artificial skin bioequivalents. RESULTS In the first patient, 10 of 13 acute or chronic wounds were found healed 3 to 6 weeks after the treatment, and the protein, iron, and hemoglobin levels normalized. Normal weight gain and marked improvement of the quality of life for this patient's family have been evident since. Nine treated wounds remained healed for at least 18 weeks and appeared to be more resistant to trauma. In a skin biopsy from a treated site obtained after 9 weeks, DNA of the graft was still detectable by polymerase chain reaction. In the second patient, who was treated at a late stage of the disease, only 2 of 18 chronic wounds were found healed at 3 weeks after the treatment. One site remained healed completely, and some additional islets of the grafts persisted for longer. There were no adverse events. CONCLUSION Early treatment with artificial skin substitutes may improve the clinical course of H-JEB. However, a true cure of the cutaneous manifestations of H-JEB would require gene therapy of autologous epidermal stem cells, which could then be transplanted by using this or a similar cultured skin bioequivalent.
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Affiliation(s)
- Qiu-Jie Jiang
- Children's Hospital and Department of Experimental Medicine, Nikolaus-Fiebiger-Center for Molecular Medicine, University of Erlangen-Nuernberg, Germany
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Pulkkinen L, Ringpfeil F, Uitto J. Progress in heritable skin diseases: molecular bases and clinical implications. J Am Acad Dermatol 2002; 47:91-104. [PMID: 12077587 DOI: 10.1067/mjd.2002.120601] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Leena Pulkkinen
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA 19107, USA
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16
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McGrath JA, Eady RA. Recent advances in the molecular basis of inherited skin diseases. ADVANCES IN GENETICS 2001; 43:1-32. [PMID: 11037297 DOI: 10.1016/s0065-2660(01)43002-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Over the last few years the molecular basis of several inherited skin diseases has been delineated. Some discoveries have stemmed from a candidate gene approach using clinical, biochemical, immunohistochemical, and ultrastructural clues, while others have arisen from genetic linkage and positional cloning analyses. Notable advances have included elucidation of specific gene pathology in the major forms of inherited skin fragility, ichthyosis, and keratoderma. These findings have led to a better understanding of the significance of individual structural proteins and regulatory enzymes in keratinocyte adhesion and differentiation. From a clinical perspective, the advances have led to better genetic counseling in many disorders, the development of DNA-based prenatal diagnosis, and a foundation for planning newer forms of treatment, including somatic gene therapy, in selected conditions.
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Affiliation(s)
- J A McGrath
- Department of Cell and Molecular Pathology, St John's Institute of Dermatology, The Guy's, Kings College and St Thomas' Hospital Medical School, St Thomas' Hospital, London, United Kingdom.
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McGrath JA. Gene mutations, great expectations. Clin Dermatol 2001; 19:59-64. [PMID: 11369489 DOI: 10.1016/s0738-081x(00)00213-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- J A McGrath
- St. John's Institute of Dermatology, The Guy's King's College and St. Thomas' Hospitals' Medical School, London, United Kingdom
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18
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Affiliation(s)
- G H Ashton
- Department of Cell and Molecular Pathology, St John's Institute of Dermatology, The Guy's, King's College and St Thomas' Hospitals' Medical School, St Thomas' Hospital, London, UK
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19
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Abstract
The laminin protein family has diverse tissue expression patterns and is involved in the pathology of a number of organs, including skin, muscle, and nerve. In the skin, laminins 5 and 6 contribute to dermal-epidermal cohesion, and mutations in the constituent chains result in the blistering phenotype observed in patients with junctional epidermolysis bullosa (JEB). Allelic heterogeneity is observed in patients with JEB: mutations that results in premature stop codons produce a more severe phenotype than do missense mutations. Gene therapy approaches are currently being studied in the treatment of this disease. A blistering phenotype is also observed in patients with acquired cicatricial pemphigoid (CP). Autoantibodies targeted against laminins 5 and 6 destabilize epithelial adhesion and are pathogenic. In muscle cells, laminin alpha 2 is a component of the bridge that links the actin cytoskeleton to the extracellular matrix. In patients with laminin alpha 2 mutations, the bridge is disrupted and mature muscle cells apoptose. Congenital muscular dystrophy (CMD) results. The role of laminin in diseases of the nervous system is less well defined, but the extracellular protein has been shown to serve an important role in peripheral nerve regeneration. The adhesive molecule influences neurite outgrowth, neural differentiation, and synapse formation. The broad spatial distribution of laminin gene products suggests that laminin may be involved in a number of diseases for which pathogenic mechanisms are still being unraveled.
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Affiliation(s)
- K A McGowan
- Department of Genetics, M-344, School of Medicine, Stanford University, Stanford, California 94305, USA
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Nakano A, Pfendner E, Hashimoto I, Uitto J. Herlitz junctional epidermolysis bullosa: novel and recurrent mutations in the LAMB3 gene and the population carrier frequency. J Invest Dermatol 2000; 115:493-8. [PMID: 11023379 DOI: 10.1046/j.1523-1747.2000.00086.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Herlitz junctional epidermolysis bullosa is a heritable bullous disease caused by mutations found primarily in the b3 chain of laminin 5 (LAMB3). In this study, we examined the LAMB3 gene for mutations in 22 Herlitz junctional epidermolysis bullosa families, and identified 15 distinct mutations, eight of them previously unreported, bringing the total number of distinct Herlitz junctional epidermolysis bullosa mutations in LAMB3 to 35. Examination of the mutation database revealed several recurrent mutations that have been reported, as well as six previously unreported. All recurrent mutations may be readily detected by polymerase chain reaction of genomic DNA and restriction endonuclease digestion. Mutation screening and prenatal diagnosis of families at risk may be expedited by molecular testing for these recurrent mutations prior to screening the entire gene. Finally, the U.S. population carrier risk for Herlitz junctional epidermolysis bullosa and all variants of junctional epidermolysis bullosa was calculated to be one in 781 and one in 350, respectively, while the overall epidermolysis bullosa carrier frequency was calculated to be one in 113. These data allow accurate testing, counseling, and risk calculation for nuclear families, as well as extended family members at risk for junctional epidermolysis bullosa.
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Affiliation(s)
- A Nakano
- Department of Dermatology and Cutaneous Biology, and Biochemistry and Molecular Pharmacology, Jefferson Medical College, Jefferson Institute of Molecular Medicine, Philadelphia, Pennsylvania 19107, USA
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Wasel N, Idikio H, Lees G, Krol A, Lin AN. Junctional epidermolysis bullosa with pyloric stenosis presenting with electron microscopic findings suggestive of epidermolysis bullosa simplex. Pediatr Dermatol 2000; 17:395-8. [PMID: 11085671 DOI: 10.1046/j.1525-1470.2000.017005395.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We present an infant girl who was born with pyloric stenosis and epidermolysis bullosa (EB). Electron microscopy of a skin biopsy specimen showed findings suggestive of EB simplex, but immunofluorescence (IF) mapping of the same specimen established the diagnosis of junctional EB. Because electron microscopy findings may sometimes be misleading, an EB patient with pyloric stenosis and electron microscopy findings suggestive of EB simplex should have a biopsy specimen examined by immunofluorescence mapping, which may confirm that the patient in fact has junctional EB.
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Affiliation(s)
- N Wasel
- Division of Dermatology and Cutaneous Sciences, University of Alberta, Edmonton, Canada
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22
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Takizawa Y, Hiraoka Y, Takahashi H, Ishiko A, Yasuraoka I, Hashimoto I, Aiso S, Nishikawa T, Shimizu H. Compound heterozygosity for a point mutation and a deletion located at splice acceptor sites in the LAMB3 gene leads to generalized atrophic benign epidermolysis bullosa. J Invest Dermatol 2000; 115:312-6. [PMID: 10951252 DOI: 10.1046/j.1523-1747.2000.00051.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An autosomal recessive disorder, generalized atrophic benign epidermolysis bullosa, is a rare form of nonlethal type junctional epidermolysis bullosa. It is associated not only with skin fragility but also with other unique clinical features including widespread atrophic skin changes, alopecia, reduced axillary and pubic hair, dysplastic teeth, and dystrophic nails. The majority of generalized atrophic benign epidermolysis bullosa cases are caused by mutations in the COL17A1 gene coding for type XVII collagen (or the 180 kDa bullous pemphigoid antigen). Another candidate gene for mutations in some forms of generalized atrophic benign epidermolysis bullosa is LAMB3 encoding the beta3 chain of laminin 5. This report documents compound heterozygosity for novel mutations in LAMB3 of a Japanese patient showing typical clinical features of generalized atrophic benign epidermolysis bullosa. One is an A-to-G transversion at the splice acceptor site of intron 14, which is designated as a 1977-2A-->G mutation; the other is a deletion of 94 bp located at the junction of intron 18 and exon 19, which is a 2702-29del94 mutation. Reverse transcriptase polymerase chain reaction analysis suggested skipping of exon 19 in LAMB3 mRNA produced from the allele with 2702-29del94 and impaired stability of the aberrant mRNA transcribed from the second allele with the 1977-2A-->G mutation.
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Affiliation(s)
- Y Takizawa
- Departments of Dermatology and Anatomy, Keio University School of Medicine, Tokyo, Japan.
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23
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Fine JD, Eady RA, Bauer EA, Briggaman RA, Bruckner-Tuderman L, Christiano A, Heagerty A, Hintner H, Jonkman MF, McGrath J, McGuire J, Moshell A, Shimizu H, Tadini G, Uitto J. Revised classification system for inherited epidermolysis bullosa. J Am Acad Dermatol 2000. [DOI: 10.1067/mjd.2000.106369] [Citation(s) in RCA: 259] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Zhou HM, Nichols A, Wohlwend A, Bolon I, Vassalli JD. Extracellular proteolysis alters tooth development in transgenic mice expressing urokinase-type plasminogen activator in the enamel organ. Development 1999; 126:903-12. [PMID: 9927592 DOI: 10.1242/dev.126.5.903] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
By catalyzing plasmin formation, the urokinase-type plasminogen activator (uPA) can generate widespread extracellular proteolysis and thereby play an important role in physiological and pathological processes. Dysregulated expression of uPA during organogenesis may be a cause of developmental defects. Targeted epithelial expression of a uPA-encoding transgene under the control of the keratin type-5 promoter resulted in enzyme production by the enamel epithelium, which does not normally express uPA, and altered tooth development. The incisors of transgenic mice were fragile, chalky-white and, by scanning electron microscopy, their labial surface appeared granular. This phenotype was attributed to a defect in enamel formation during incisor development, resulting from structural and functional alterations of the ameloblasts that differentiate from the labial enamel epithelium. Immunofluorescence revealed that disorganization of the ameloblast layer was associated with a loss of laminin-5, an extracellular matrix molecule mediating epithelial anchorage. Amelogenin, a key protein in enamel formation, was markedly decreased at the enamel-dentin junction in transgenics, presumably because of an apparent alteration in the polarity of its secretion. In addition, increased levels of active transforming growth factor-beta could be demonstrated in mandibles of transgenic mice. Since the alterations detected could be attributed to uPA catalytic activity, this model provides evidence as to how dysregulated proteolysis, involving uPA or other extracellular proteases, may have developmental consequences such as those leading to enamel defects.
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Affiliation(s)
- H M Zhou
- Department of Morphology, University of Geneva Medical School, Geneva, Switzerland
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25
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Abstract
Cutaneous basement membrane zone (BMZ) consists of a number of attachment structures that are critical for stable association of the epidermis to the underlying dermis. These include hemidesmosomes, anchoring filaments and anchoring fibrils which form an interconnecting network extending from the intracellular milieu of basal keratinocytes across the dermal-epidermal basement membrane to the underlying dermis. Aberrations in this network structure, e.g. due to genetic lesions in the corresponding genes, can result in fragility of the skin at the level of the cutaneous BMZ. The prototype of such diseases is epidermolysis bullosa (EB), a heterogeneous group of genodermatoses characterized by fragility and blistering of the skin, often associated with extracutaneous manifestations, and inherited either in an autosomal dominant or autosomal recessive manner. Based on constellations of the phenotypic manifestations, severity of the disease, and the level of tissue separation within the cutaneous BMZ, EB has been divided into clinically distinct subcategories, including the simplex, hemidesmosomal, junctional and dystrophic variants. Elucidation of BMZ gene/protein systems and development of mutation detection strategies have allowed identification of mutations in 10 different BMZ genes which can explain the clinical heterogeneity of EB. These include mutations in the type VII collagen gene (COL7A1) in the dystrophic (severely scarring) forms of EB; mutations in the laminin 5 genes (LAMA3, LAMB3 and LAMC2) in a lethal (Herlitz) variant of junctional EB; aberrations in the type XVII collagen gene (COL17A1) in non-lethal forms of junctional EB; mutations in the alpha6 and beta4 integrin genes in a distinct hemidesmosomal variant of EB with congenital pyloric atresia; and mutations in the plectin gene (PLEC1) in a form of EB associated with late-onset muscular dystrophy. Identification of mutations in these gene/protein systems attests to their critical importance in the overall stability of the cutaneous BMZ. Furthermore, elucidation of mutations in different variants of EB has direct clinical applications in terms of refined classification, improved genetic counseling, and development of DNA-based prenatal testing in families with EB.
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Affiliation(s)
- L Pulkkinen
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
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26
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Abstract
The prenatal diagnosis (PND) of severe hereditary skin diseases started in the early 1980s using fetal skin biopsy techniques based on ultrastructural and immunohistochemical abnormalities of the fetal skin. Recent success in identifying responsible genes and demonstrating mutations in such genes has set the stage for DNA-based PND in the 1990s. Common examples of skin conditions which can be prenatally diagnosed include epidermolysis bullosa, oculocutaneous albinism and Harlequin ichthyosis in which the severity of the clinical phenotype appears to justify PND in families at risk. More recently, preimplantation diagnoses of inherited diseases have become possible using in vitro fertilization techniques. The diagnosis consists of a blastomere biopsy of the six to ten-cell embryo and a DNA analysis of single blastomeres. Disease-free embryos are selected for transfer to the uterus, thereby avoiding the need for termination of a fetus found to be affected by conventional PND. Furthermore, carrying out a PND using a single fetal cell from the maternal blood, such as nucleated erythrocytes, has become technically feasible. Although there are many questions that remain unanswered, the outlook for further development of noninvasive PND in the future appears optimistic.
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Affiliation(s)
- H Shimizu
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.
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27
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Takizawa Y, Shimizu H, Pulkkinen L, Suzumori K, Kakinuma H, Uitto J, Nishikawa T. Combination of a novel frameshift mutation (1929delCA) and a recurrent nonsense mutation (W610X) of the LAMB3 gene in a Japanese patient with Herlitz junctional epidermolysis bullosa, and their application for prenatal testing. J Invest Dermatol 1998; 111:1239-41. [PMID: 9856852 DOI: 10.1038/sj.jid.5600370] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Gene in a Japanese Patient with Herlitz Junctional Epidermolysis Bullosa, and their Application for Prenatal Testing. J Invest Dermatol 1998. [DOI: 10.1046/j.1523-1747.1998.00447.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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29
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Pulkkinen L, Rouan F, Bruckner-Tuderman L, Wallerstein R, Garzon M, Brown T, Smith L, Carter W, Uitto J. Novel ITGB4 mutations in lethal and nonlethal variants of epidermolysis bullosa with pyloric atresia: missense versus nonsense. Am J Hum Genet 1998; 63:1376-87. [PMID: 9792864 PMCID: PMC1377547 DOI: 10.1086/302116] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Epidermolysis bullosa with pyloric atresia (EB-PA), an autosomal recessive genodermatosis, manifests with neonatal cutaneous blistering associated with congenital pyloric atresia. The disease is frequently lethal, but nonlethal cases have also been reported. Expression of the alpha6 beta4 integrin is altered at the dermal-epidermal basement-membrane zone; recently, mutations in the corresponding genes (ITGA6 and ITGB4) have been disclosed in a limited number of patients, premature termination codons in both alleles being characteristic of lethal variants. In this study, we have examined the molecular basis of EB-PA in five families, two of them with lethal and three of them with nonlethal variants of the disease. Mutation analysis disclosed novel lesions in both ITGB4 alleles of each proband. One of the patients with lethal EB-PA was a compound heterozygote for premature termination-codon mutations (C738X/4791delCA), whereas the other patient with a lethal variant was homozygous for a missense mutation involving a cysteine residue (C61Y). The three nonlethal cases had missense mutations in both alleles (C562R/C562R, R1281W/R252C, and R1281W/R1281W). Immunofluorescence staining of skin in two of the nonlethal patients and in one of the lethal cases was positive, yet attenuated, for alpha6 and beta4 integrins. These results confirm that ITGB4 mutations underlie EB-PA and show that missense mutations may lead to nonlethal phenotypes.
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Affiliation(s)
- L Pulkkinen
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Philadelphia, PA 19107, USA
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Pulkkinen L, Uitto J. Hemidesmosomal variants of epidermolysis bullosa. Mutations in the alpha6beta4 integrin and the 180-kD bullous pemphigoid antigen/type XVII collagen genes. Exp Dermatol 1998; 7:46-64. [PMID: 9583744 DOI: 10.1111/j.1600-0625.1998.tb00304.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Epidermolysis bullosa (EB), a heterogeneous group of genodermatoses, is characterized by fragility and blistering of the skin, associated with characteristic extracutaneous manifestations. Based on clinical severity, constellation of the phenotypic manifestations, and the level of tissue separation within the cutaneous basement membrane zone, EB has been divided into distinct subcategories. Traditionally, these include the simplex, junctional and dystrophic variants of EB. Recent attention has been drawn to variants of EB demonstrating tissue separation at the level of hemidesmosomes, ultrastructurally recognizable adhesion complexes within the cutaneous basement membrane zone. Clinically, these hemidesmosomal variants manifest either as generalized atrophic benign epidermolysis bullosa (GABEB), EB with pyloric atresia, or EB with late-onset muscular dystrophy. Elucidation of basement membrane zone components by molecular cloning and development of mutation detection strategies have revealed that the hemidesmosomal variants of EB result from mutations in the genes encoding the subunit polypeptides of the 180-kD bullous pemphigoid antigen/type XVII collagen, the alpha6beta4 integrin, or plectin, respectively. Collectively, these data add to the understanding of the molecular complexity of the cutaneous basement membrane zone in EB, as attested by the fact that mutations in 10 different genes can underlie different variants of EB. Elucidation of mutations in different forms of EB has direct application to genetic counseling and DNA-based prenatal testing in families with EB.
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Affiliation(s)
- L Pulkkinen
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
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31
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Abstract
Considerable progress has been made recently in elucidating the molecular pathology underlying several forms of inherited skin diseases. One of the most immediate benefits of these discoveries has been the development of DNA-based prenatal diagnosis in pregnancies at risk for recurrence of a particular disorder. In less than 2 decades, prenatal testing has progressed from mid-trimester fetal skin biopsies or protein analysis in a limited number of conditions to first trimester chorionic villus sampling in a much broader range of genodermatoses. Advances in in vitro fertilization protocols and embryo manipulation technology have further led to the feasibility of even earlier prenatal diagnosis through preimplantation genetic diagnosis. This article details some of the recent advances in genetic skin disease research relevant to prenatal diagnosis and explores the possibilities and practicalities of preimplantation genetic diagnosis in the prevention of these conditions.
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Affiliation(s)
- J A McGrath
- Department of Cell and Molecular Pathology, St John's Institute of Dermatology, London, UK
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Takizawa Y, Shimizu H, Pulkkinen L, Hiraoka Y, McGrath JA, Suzumori K, Aiso S, Uitto J, Nishikawa T. Novel mutations in the LAMB3 gene shared by two Japanese unrelated families with Herlitz junctional epidermolysis bullosa, and their application for prenatal testing. J Invest Dermatol 1998; 110:174-8. [PMID: 9457915 DOI: 10.1046/j.1523-1747.1998.00105.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The LAMB3 gene encoding the beta3 chain of laminin 5 is a candidate gene for mutations in the autosomal recessive blistering skin disorder, junctional epidermolysis bullosa. In this study, we performed genetic analyses in two unrelated Japanese families with Herlitz junctional epidermolysis bullosa and identified two novel nonsense mutations in the LAMB3 gene. One of them, Q166X (CAG --> TAG), was found in the maternal allele of family 1 and the paternal allele of family 2. Conversely, the other mutation, W610X (TGG --> TGA), was found in the paternal allele of family 1 and the maternal allele of family 2. Thus, probands of both families were compound heterozygotes for these nonsense mutations. Haplotype analyses with intragenic LAMB3 polymorphisms suggested that both mutations had arisen independently in these two families. Both mutations create a premature translation termination codon predicting truncated beta3 chains that lead to absent expression of laminin 5 in the epidermal basement membrane zone. Based on these results, DNA-based prenatal diagnosis was performed by chorionic villus sampling for subsequent pregnancies in both families. Both fetuses were found to be heterozygous carriers of the W610X mutation together with a normal LAMB3 allele, indicating that they were phenotypically unaffected. These findings expand the repertoire of LAMB3 mutations in junctional epidermolysis bullosa, and emphasize the notion that premature termination codons in both alleles of the laminin 5 genes result in Herlitz junctional epidermolysis bullosa.
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Affiliation(s)
- Y Takizawa
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
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33
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Uitto J, Pulkkinen L, McLean WH. Epidermolysis bullosa: a spectrum of clinical phenotypes explained by molecular heterogeneity. MOLECULAR MEDICINE TODAY 1997; 3:457-65. [PMID: 9358473 DOI: 10.1016/s1357-4310(97)01112-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Great progress has recently been made in understanding the molecular basis of various heritable skin diseases. A prototype of such conditions is epidermolysis bullosa (EB), a heterogeneous group of mechano-bullous disorders characterized by fragility of the skin and other specialized epithelia. Blistering of the skin in EB results either from fragility of epidermal cells or from defective attachment of the epidermis to the underlying dermis, because of genetic lesions within molecules of the basement-membrane zone at the dermal-epidermal junction. Distinct mutations have been discovered in ten different genes encoding the structural components within this layer. The combinations and the types of mutations, as well as their positions in the altered gene products, collectively reflect the phenotypic variability observed in this group of heritable skin diseases.
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Affiliation(s)
- J Uitto
- Jefferson Medical College, Dept of Dermatology and Cutaneous Biology, Philadelphia, PA 19107, USA.
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Pulkkinen L, Meneguzzi G, McGrath JA, Xu Y, Blanchet-Bardon C, Ortonne JP, Christiano AM, Uitto J. Predominance of the recurrent mutation R635X in the LAMB3 gene in European patients with Herlitz junctional epidermolysis bullosa has implications for mutation detection strategy. J Invest Dermatol 1997; 109:232-7. [PMID: 9242513 DOI: 10.1111/1523-1747.ep12319752] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Junctional forms of epidermolysis bullosa (JEB) are characterized by tissue separation at the level of the lamina lucida. We have recently disclosed specific mutations in the LAMA3, LAMB3, and LAMC2 genes encoding the subunit polypeptides of the anchoring filament protein laminin 5 in 66 families with different variants of JEB. Examination of the JEB mutation database revealed recurrence of a particular C-->T substitution at nucleotide position 1903 (exon 14) of LAMB3, resulting in the mutation R635X. The inheritance of this nonsense mutation was noted on different genetic backgrounds, suggesting that R635X is a hotspot mutation. In this study, we have performed mutation evaluation in a European cohort of 14 families with the lethal, Herlitz type of JEB (H-JEB). The families were first screened for the presence of the R635X mutation by restriction enzyme digestion of the PCR product corresponding to exon 14. Four of the probands were found to be homozygous and six were heterozygous for R635X. The remaining alleles were subjected to mutation screening by PCR amplification of individual exons of LAMB3 and LAMC2, followed by heteroduplex analysis and nucleotide sequencing. In three families (six alleles), mutations in LAMC2 were disclosed. In the remaining eight alleles, additional pathogenetic LAMB3 mutations were found. None of the patients had LAMA3 mutation. Thus, LAMB3 mutations accounted for 22 of 28 JEB alleles (79%), and a total of 14 of 22 LAMB3 alleles (64%) harbored the R635X mutation, signifying its prevalence as a predominant genetic lesion underlying H-JEB in this European cohort of patients. This recurrent mutation will facilitate screening of additional JEB patients for the purpose of prenatal testing of fetuses at risk for recurrence.
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Affiliation(s)
- L Pulkkinen
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, U.S.A
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35
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Pulkkinen L, McGrath J, Airenne T, Haakana H, Tryggvason K, Kivirikko S, Meneguzzi G, Ortonne JP, Christiano AM, Uitto J. Detection of Novel LAMC2 Mutations in Herlitz Junctional Epidermolysis Bullosa. Mol Med 1997. [DOI: 10.1007/bf03401804] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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