1
|
Medeiros GX, Riet-Correa F. Epidermolysis bullosa in animals: a review. Vet Dermatol 2014; 26:3-13, e1-2. [PMID: 25354580 DOI: 10.1111/vde.12176] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2014] [Indexed: 11/30/2022]
Abstract
Epidermolysis bullosa (EB) is a hereditary mechanobullous disease of animals and humans, characterized by an extreme fragility of the skin and mucous membranes. The main feature of EB in humans and animals is the formation of blisters and erosions in response to minor mechanical trauma. Epidermolysis bullosa is caused by mutations in the genes that code for structural proteins of the cytoskeleton of the basal keratinocytes or of the basement membrane zone. Based on the ultrastructural levels of tissue separation, EB is divided into the following three broad categories: epidermolysis bullosa simplex, junctional epidermolysis bullosa and dystrophic epidermolysis bullosa. Human types of EB are divided into several subtypes based on their ultrastructural changes and the mode of inheritance; subtypes are not fully established in animals. In humans, it is estimated that EB affects one in 17,000 live births; the frequency of EB in different animals species is not known. In all animal species, except in buffalo with epidermolysis bullosa simplex, multifocal ulcers are observed on the gums, hard and soft palates, mucosa of the lips, cheek mucosa and dorsum of the tongue. Dystrophic or absent nails, a frequent sign seen in human patients with EB, corresponds to the deformities and sloughing of the hooves in ungulates and to dystrophy or atrophy of the claws in dogs and cats. This review covers aspects of the molecular biology, diagnosis, classification, clinical signs and pathology of EB reported in animals.
Collapse
Affiliation(s)
- Gildenor X Medeiros
- Postgraduate Program in Veterinary Medicine, Veterinary Hospital, Federal University of Campina Grande, Patos, Paraíba, CEP 58708-110, Brazil
| | | |
Collapse
|
2
|
Dystrophic Epidermolysis Bullosa in Goats. J Comp Pathol 2013; 148:354-60. [DOI: 10.1016/j.jcpa.2012.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 05/01/2012] [Accepted: 09/03/2012] [Indexed: 11/22/2022]
|
3
|
Chung HJ, Uitto J. Type VII collagen: the anchoring fibril protein at fault in dystrophic epidermolysis bullosa. Dermatol Clin 2010; 28:93-105. [PMID: 19945621 DOI: 10.1016/j.det.2009.10.011] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Type VII collagen is a major component of the anchoring fibrils of the dermal-epidermal adhesion on the dermal side at the lamina densa/papillary dermis interface. Dystrophic epidermolysis bullosa (DEB) emerged as a candidate for type VII collagen mutations becausing anchoring fibrils were shown to be morphologically altered, reduced in number, or completely absent in patients with different forms of DEB. Circulating autoantibodies recognize type VII collagen epitopes in epidermolysis bullosa acquisita. The suggestion that type VII collagen is required for human epidermal tumorigenesis relates to the increasing numbers of life-threatening complications associated with developing squamous cell carcinomas because of the extended life span of affected individuals with recessive DEB.
Collapse
Affiliation(s)
- Hye Jin Chung
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, 233 South 10th Street, Suite 450 BLSB, Philadelphia, PA 19107, USA
| | | |
Collapse
|
4
|
Lee HS, Park K, son SJ, Song KY, Kim SE. Pretibial epidermolysis bullosa: is this case a new subtype with loss of types IV and VII collagen? Int J Dermatol 2009; 48:879-81. [DOI: 10.1111/j.1365-4632.2008.03983.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
5
|
Ouragini H, Cherif F, Kassar S, Floriddia G, Pascucci M, Daoud W, Osman-Dhahri AB, Boubaker S, Castiglia D, Abdelhak S. Dystrophic epidermolysis bullosa phenotypes in a large consanguineous Tunisian family. J Dermatol Sci 2009; 54:114-20. [PMID: 19261445 DOI: 10.1016/j.jdermsci.2009.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 01/20/2009] [Accepted: 01/26/2009] [Indexed: 10/21/2022]
Abstract
BACKGROUND Dystrophic epidermolysis bullosa (DEB) is a clinically heterogeneous blistering disorder of the skin and mucous membranes. DEB is caused by mutations in the COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils. On the basis of the mode of inheritance and the clinical manifestations, DEB is classified into two major subtypes: one dominant (DDEB) and one recessive (RDEB). OBJECTIVE We report, here, clinical, histological and genetic investigation of a large Tunisian family presenting with a wide range of clinical manifestations of DEB and a pedigree suggestive for a pseudodominant pattern of inheritance of a recessive mutation. METHODS Indirect immunofluorescence (IF) with the antibody LH7:2 against collagen VII and electron microscopy (EM) analyses were performed. The members of the family were genotyped with five markers flanking COL7A1, and screening for the deleterious mutation by DHPLC and direct sequencing. RESULTS The family presented four pretibial DEB patients and one generalized RDEB. Molecular investigation showed that all family members, unaffected and affected by the pretibial form, were heterozygous for the c.7178delT mutation, except for the member with the generalized form who was homozygous. IF showed that heterozygous individuals, independently of their clinical status, have a slightly reduced staining, and the homozygous individual with generalized DEB has markedly reduced staining at the dermal-epidermal junction. CONCLUSION These results are suggestive for an autosomal semidominant model of inheritance with incomplete penetrance and variable expression for the identified mutation. No genotype phenotype correlation was observed suggesting the existence of other genetic determinants influencing dermo-epidermal junction cohesion.
Collapse
Affiliation(s)
- Houyem Ouragini
- Molecular Investigation of Genetic Orphan Diseases Research Unit (MIGOD), Institut Pasteur de Tunis, BP 74, 13 Place Pasteur, Tunis Belvedere 1002, Tunisia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Tang WY, Lee KC, Chow TC, Lo KK. Three Hong Kong Chinese cases of pretibial epidermolysis bullosa: a genodermatosis that can masquerade as an acquired inflammatory disease. Clin Exp Dermatol 1999; 24:149-53. [PMID: 10354166 DOI: 10.1046/j.1365-2230.1999.00440.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Three patients in two families presented with many years' history of fragile skin, blisters, erosions and scars affecting almost exclusively the shin areas, accompanied by a variable degree of itching. Two of the patients also had toenail dystrophy. Skin biopsy revealed dermal-epidermal blister formation and milia but no immunohistochemical evidence of immunoglobulin or complement deposition. Electron microscopic study of the lesional and perilesional skin showed very sparse or absent anchoring fibrils. Immunolabelling for type VII collagen using LH 7.2 monoclonal antibody revealed a bright, linear staining pattern at the dermal-epidermal junction. The clinicopathological features were thus compatible with pretibial epidermolysis bullosa, a subtype of dystrophic epidermolysis bullosa. Of note, the inflammatory nature of the skin lesions, and their resemblance to nodular prurigo and hypertrophic lichen planus, had caused diagnostic difficulties in all cases in the past. A high degree of awareness of this rare subtype of epidermolysis bullosa is important to establish the correct diagnosis, to allow for genetic counselling and to plan clinical management.
Collapse
Affiliation(s)
- W Y Tang
- Social Hygiene Service, Department of Health, the Government of the Hong Kong Special Administrative Region, Hong Kong
| | | | | | | |
Collapse
|
7
|
Sakuntabhai A, Hammami-Hauasli N, Bodemer C, Rochat A, Prost C, Barrandon Y, de Prost Y, Lathrop M, Wojnarowska F, Bruckner-Tuderman L, Hovnanian A. Deletions within COL7A1 exons distant from consensus splice sites alter splicing and produce shortened polypeptides in dominant dystrophic epidermolysis bullosa. Am J Hum Genet 1998; 63:737-48. [PMID: 9718359 PMCID: PMC1377417 DOI: 10.1086/302029] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
We describe two familial cases of dominant dystrophic epidermolysis bullosa (DDEB) that are heterozygous for deletions in COL7A1 that alter splicing, despite intact consensus splice-site sequences. One patient shows a 28-bp genomic deletion (6081del28) in exon 73 associated with the activation of a cryptic donor splice site within this exon; the combination of both defects restores the phase and replaces the last 11 Gly-X-Y repeats of exon 73 by a noncollagenous sequence, Glu-Ser-Leu. The second patient demonstrates a 27-bp deletion in exon 87 (6847del27), causing in-frame skipping of this exon; consensus splice sites, putative branch sites, and introns flanking exons 73 and 87 showed a normal sequence. Keratinocytes from the probands synthesized normal and shortened type VII collagen polypeptides and showed intracellular accumulation of type VII procollagen molecules. This first report of genomic deletions in COL7A1 in DDEB suggests a role for exonic sequences in the control of splicing of COL7A1 pre-mRNA and provides evidence that shortened type VII collagen polypeptides can alter, in a dominant manner, anchoring-fibril formation and can cause DDEB of differing severity.
Collapse
Affiliation(s)
- A Sakuntabhai
- Wellcome Trust Centre for Human Genetics, University of Oxford, Headington, Oxford OX3 7BN, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Torrelo A, Valverde E, Zambrano A. Informativeness of polymorphic markers for prenatal diagnosis of recessive dystrophic epidermolysis bullosa in Spanish families at risk. J Dermatol Sci 1998; 17:233-8. [PMID: 9697052 DOI: 10.1016/s0923-1811(98)00020-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
DNA polymorphic markers are useful for the prenatal diagnosis of generalized recessive dystrophic epidermolysis bullosa (GRDEB) in families with at least one child affected with the disease. It is our policy to investigate families at risk using DNA polymorphic markers before a new pregnancy is intended, to inform about the real chances of offering an accurate prenatal diagnosis based on such DNA markers. We have analysed 10 Spanish families with at least one child affected with GRDEB with three different markers linked to the type VII collagen gene: the intragenic PvuII RFLP, and two markers mapped close to the COL7A1 gene, an MspI polymorphism belonging to the anonymous marker D3S2, and the microsatellite D3S1100. The PvuII marker was partially informative in two of 10 families, and was fully informative in three additional families; The MspI marker was partially informative in two of 10 families, and was fully informative in three additional families; it was not informative in five families. The D3S1100 microsatellite was partially informative in two out of 10 families, and fully informative in the other eight families. Combination of all three markers was shown to be partially informative in one family and fully informative in the remaining nine families. Using this combination of markers, we have inferred an accurate linkage-based prenatal diagnosis of GRDEB in four pregnancies. Surprisingly, the intragenic marker PvuII had a very limited usefulness, despite the results of previous studies; the microsatellite D3S1100 offered the best results for an eventual prenatal diagnosis of GRDEB. However, families at risk should be informed that extragenic markers may fail due to the possibility of recombination, estimated as 5% for D3S1100.
Collapse
Affiliation(s)
- A Torrelo
- Department of Dermatology, Hospital del Niño Jesús, Madrid, Spain
| | | | | |
Collapse
|
9
|
Arbiser JL, Fine JD, Murrell D, Paller A, Connors S, Keough K, Marsh E, Folkman J. Basic Fibroblast Growth Factor: A Missing Link between Collagen VII, Increased Collagenase, and Squamous Cell Carcinoma in Recessive Dystrophic Epidermolysis Bullosa. Mol Med 1998. [DOI: 10.1007/bf03401916] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
|
10
|
Arbiser JL, Fine JD, Murrell D, Paller A, Connors S, Keough K, Marsh E, Folkman J. Basic fibroblast growth factor: a missing link between collagen VII, increased collagenase, and squamous cell carcinoma in recessive dystrophic epidermolysis bullosa. Mol Med 1998; 4:191-5. [PMID: 9562977 PMCID: PMC2230348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Patients with recessive dystrophic epidermolysis bullosa (RDEB) have deficiencies of collagen type VII and have elevated levels of fibroblast collagenase, and a greatly increased risk of cutaneous squamous cell carcinoma. Patients with other genetic blistering disorders do not have elevated collagenase or an increased risk of squamous cell carcinoma, despite chronic wounding. The connection between collagen type VII deficiency, increased collagenase, and squamous cell carcinoma is not understood. MATERIALS AND METHODS Urine from 81 patients with RDEB (39 patients), junctional epidermolysis bullosa (JEB; 12 patients), and epidermolysis bullosa simplex (EBS; 30 patients), as well as unaffected family members of RDEB patients (33 patients), was tested for the presence of basic fibroblast growth factor (bFGF) using a sensitive radioimmunoassay. These patients included many who were enrolled in the Epidermolysis Bullosa Registry and others who were referred by their physicians. RESULTS Fifty-one percent of patients with RDEB had elevated levels (> 5000 pg/g) of urinary bFGF. In contrast, none of the patients with JEB had elevated levels of bFGF. Twenty-one percent of clinically unaffected family members had elevated levels of bFGF, and 13% of patients with EBS had elevated levels of bFGF. The frequency of elevated bFGF values among all groups was statistically significant (p = 0.002), and the levels of bFGF in RDEB patients were significantly elevated compared with those of other groups (p < 0.05). CONCLUSIONS We have found that patients with RDEB have elevated levels of bFGF, which may contribute to increased fibroblast collagenase and the development of squamous cell carcinoma. These results suggest a novel treatment for RDEB, namely, angiogenesis inhibitors, which may antagonize the effects of bFGF in this disorder. There are currently no other means of treatment for this disorder, which has a high morbidity and mortality rate.
Collapse
Affiliation(s)
- J L Arbiser
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
Spectacular success has recently been made in understanding the molecular basis of various heritable skin diseases. A prototype of such conditions is epidermolysis bullosa (EB), a heterogenous group of mechano-bullous disorders, characterized by fragility of the skin and other specialized epithelia. The fragility of the skin in EB results from defective attachment of the epidermis to the underlying dermis due to genetic lesions within molecules of the basement membrane zone (BMZ) at the dermal-epidermal junction. Specifically, distinct mutations have been disclosed thus far in ten different genes encoding the macromolecular components of the BMZ, and the combinations and the types of mutations as well as their positions along the altered gene products collectively reflect the phenotypic variability observed in this group of heritable skin diseases. This information has major implications for genetic counseling of families at risk for recurrence of EB in subsequent pregnancies and in future generations. Furthermore, examination of specific mutations in an affected newborn allows prognostication of the severity of the clinical outcome. Finally, mutation analyses have provided the basis to develop DNA-based prenatal testing by chorionic villus sampling or early aminocentesis during the first trimester of gestation. Collectively, the advances on EB exemplify the potential of molecular biology for improved diagnosis and patient care of genetic skin disorders.
Collapse
Affiliation(s)
- J Uitto
- Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| |
Collapse
|
12
|
Hovnanian A, Rochat A, Bodemer C, Petit E, Rivers CA, Prost C, Fraitag S, Christiano AM, Uitto J, Lathrop M, Barrandon Y, de Prost Y. Characterization of 18 new mutations in COL7A1 in recessive dystrophic epidermolysis bullosa provides evidence for distinct molecular mechanisms underlying defective anchoring fibril formation. Am J Hum Genet 1997; 61:599-610. [PMID: 9326325 PMCID: PMC1715975 DOI: 10.1086/515495] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have characterized 21 mutations in the type VII collagen gene (COL7A1) encoding the anchoring fibrils, 18 of which were not previously reported, in patients from 15 unrelated families with recessive dystrophic epidermolysis bullosa (RDEB). COL7A1 mutations in both alleles were identified by screening the 118 exons of COL7A1 and flanking intron regions. Fourteen mutations created premature termination codons (PTCs) and consisted of nonsense mutations, small insertions, deletions, and splice-site mutations. A further seven mutations predicted glycine or arginine substitutions in the collagenous domain of the molecule. Two mutations were found in more than one family reported in this study, and six of the seven missense mutations showed clustering within exons 72-74 next to the hinge region of the protein. Patients who were homozygous or compound heterozygotes for mutations leading to PTCs displayed both absence or drastic reduction of COL7A1 transcripts and undetectable type VII collagen protein in skin. In contrast, missense mutations were associated with clearly detectable COL7A1 transcripts and with normal or reduced expression of type VII collagen protein at the dermo/epidermal junction. Our results provide evidence for at least two distinct molecular mechanisms underlying defective anchoring fibril formation in RDEB: one involving PTCs leading to mRNA instability and absence of protein synthesis, the other implicating missense mutations resulting in the synthesis of type VII collagen polypeptide with decreased stability and/or altered function. Genotype-phenotype correlations suggested that the nature and location of these mutations are important determinants of the disease phenotype and showed evidence for interfamilial phenotypic variability.
Collapse
Affiliation(s)
- A Hovnanian
- The Wellcome Trust Centre for Human Genetics, University of Oxford, United Kingdom.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Lee JY, Pulkkinen L, Liu HS, Chen YF, Uitto J. A glycine-to-arginine substitution in the triple-helical domain of type VII collagen in a family with dominant dystrophic epidermolysis bullosa pruriginosa. J Invest Dermatol 1997; 108:947-9. [PMID: 9182828 DOI: 10.1111/1523-1747.ep12296242] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Epidermolysis bullosa pruriginosa is a recently recognized variant of dystrophic epidermolysis bullosa (DEB) characterized by severe pruritus and scarring, mainly involving the extensors of the extremities. In this study, we searched for mutations in the type VII collagen gene (COL7A1) using polymerase chain reaction amplification of exonic segments of COL7A1, followed by heteroduplex analysis, in a Chinese pedigree with dominant DEB displaying a striking anastomosing network of lichenoid papules and scarring. The study revealed a G-to-A transition at nucleotide 6724 within exon 85 of COL7A1, converting a glycine to an arginine (G2242R) within the triple-helical domain of the type VII collagen in affected individuals. These findings demonstrate that EB pruriginosa in this family is a clinical variant of dominant DEB.
Collapse
Affiliation(s)
- J Y Lee
- Department of Dermatology, National Cheng Kung University Hospital, Tainan, Taiwan, R.O.C
| | | | | | | | | |
Collapse
|
14
|
Dunnill MG, McGrath JA, Richards AJ, Christiano AM, Uitto J, Pope FM, Eady RA. Clinicopathological correlations of compound heterozygous COL7A1 mutations in recessive dystrophic epidermolysis bullosa. J Invest Dermatol 1996; 107:171-7. [PMID: 8757758 DOI: 10.1111/1523-1747.ep12329570] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Recessive dystrophic epidermolysis bullosa is an inherited mechano-bullous disorder of skin and mucous membranes. Ultrastructurally, the disease is characterized by abnormalities of anchoring fibrils, attachment structures below the epidermal basement membrane, composed of type VII collagen. Mutations in the type VII collagen gene (COL7A1) have been shown conclusively to underlie dystrophic epidermolysis bullosa. Since there is variation of the phenotype, accompanied by heterogeneous anchoring fibril morphology and type VII collagen immunostaining, it is conceivable that different types and combinations of COL7A1 mutations correlate with different phenotypes. We therefore screened recessive dystrophic epidermolysis bullosa patients for COL7A1 mutations. Three unrelated patients showed the same premature termination codon mutation in exon 13 of one allele, yet they were all compound heterozygotes, each having a different mutation in the second allele. The first patient had a premature termination codon within the collagenous region of COL7A1 associated with severe disease, absent anchoring fibrils and undetectable type VII collagen immunostaining. The second had a premature termination codon in the non-collagenous NC-2 region associated with severe disease, wispy anchoring fibrils, and patchy type VII collagen immunostaining. The third had a glycine-to-aspartic acid substitution within the collagenous region, associated with milder disease, no identifiable anchoring fibrils, but near normal type VII collagen immunostaining. We conclude that the nature and position of mutations within COL7A1 correlate with specific disease features and may provide an insight into the molecular mechanisms of anchoring fibril formation and epidermal-dermal adhesion.
Collapse
Affiliation(s)
- M G Dunnill
- St. John's Institute of Dermatology, St. Thomas' Hospital, London, U.K
| | | | | | | | | | | | | |
Collapse
|
15
|
Christiano AM, D'Alessio M, Paradisi M, Angelo C, Mazzanti C, Puddu P, Uitto J. A common insertion mutation in COL7A1 in two Italian families with recessive dystrophic epidermolysis bullosa. J Invest Dermatol 1996; 106:679-84. [PMID: 8618004 DOI: 10.1111/1523-1747.ep12345508] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Recessive dystrophic epidermis bullosa is ultrastructurally characterized by the absence of anchoring fibrils, and genetic analyses have revealed that recessive dystrophic epidermolysis bullosa results from mutations in the type VII collagen gene (COL7A1). The mutations disclosed thus far are largely family specific, with no evidence for mutational hotspot(s). In this study, we report a recurrent premature termination codon mutation detected in two apparently unrelated Italian families in different regions of the country. This mutation, 497insA in exon 4 of COL7A1, was found in combination with two different premature termination codon mutations in these families. Haplotype analysis suggested a shared genetic background in the allele containing the mutation 497insA, suggesting that this genetic lesion may represent an ancestral mutation within the Italian gene pool.
Collapse
Affiliation(s)
- A M Christiano
- Department of Dermatology, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA
| | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
In the past 5 years enormous progress have been made in our understanding of the molecular basis for a number of inherited skin diseases characterized by easy blistering of the skin and the mucous membranes after minor physical trauma. This increased fragility of the skin or its appendages is due to molecular defects in genes coding for different intra- and extracellular structural proteins which are responsible for mechanical strength at their sites of expression. These diseases encompass the group of epidermolysis bullosa and disorders of cornification such as bullous forms of ichthyosis, palmoplantar keratoderma, and pachyonychia congenita. On the basis of clinical, morphological, and ultrastructural observations the epidermolysis bullosa group has been divided into three major categories. In epidermolysis bullosa simplex blister formation appears within the basal cell layer of the epidermis, and many mutations have been found in the genes of keratin 5 and 14 which are both expressed in basal keratinocytes. Epidermolytic hyperkeratosis leads to an epidermal separation in the suprabasal cell layers. In these patients numerous point mutations have now been described in the suprabasally expressed genes of keratin 1 and 10. In ichthyosis bullosa of Siemens blisters occur in the more upper suprabasal epidermis coincidental with the expression of keratin 2e, and mutations have been detected in the corresponding gene. In epidermolytic palmoplantar hyperkeratosis the suprabasal epidermal splitting is restricted to palms and soles of the patient. In keratin 9, which reveals such an exclusive expression pattern, molecular defects have indeed been recognized. Most recently in two different clinical subtypes of pachyonychia congenita, which is characterized by defective nails and focal palmoplantar hyperkeratosis, point mutations have been found in the genes coding for keratins 6, 16, and 17. In junctional epidermolysis bullosa the separation takes place within the dermal-epidermal basement membrane at the level of the lamina lucida, and mutations have been found in three genes coding for different laminin chains, in the beta4 gene of alpha6beta4 integrin, and in the gene of collagen XVII. In dystrophic epidermolysis bullosa the tissue separation occurs beneath the basement membrane within the papillary dermis at the level of the anchoring fibrils, and several mutations have been identified in the collagen VII gene. The rapid unraveling of molecular defects in these disabling or even lethal inherited skin diseases makes possible a more precise and earlier prenatal diagnosis, creates new options for suitable therapeutic regimens, and even offers the hope of curing these diseases by means of somatic cell gene therapy.
Collapse
Affiliation(s)
- B P Korge
- Klinik und Poliklinik fur Dermatologie und Venerologie, Universitat Koln, Germany
| | | |
Collapse
|
17
|
Shimizu H, McGrath JA, Christiano AM, Nishikawa T, Uitto J. Molecular basis of recessive dystrophic epidermolysis bullosa: genotype/phenotype correlation in a case of moderate clinical severity. J Invest Dermatol 1996; 106:119-24. [PMID: 8592061 DOI: 10.1111/1523-1747.ep12329600] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mutations within the gene encoding the anchoring fibril protein type VII collagen (COL7A1) have recently been established as the pathogenetic basis for the inherited blistering skin disorder, dystrophic epidermolysis bullosa. We report a patient with a moderately severe phenotype of recessive dystrophic epidermolysis bullosa. We report a patient with a moderately severe phenotype of recessive dystrophic epidermolysis bullosa, in whom COL7A1 mutations have been identified on both alleles. The patient is a 5-y-old Japanese male of nonconsanguineous parents, with clinical features including generalized trauma-induced blistering since birth, complete loss of nails, and partial fusion of the fingers and toes. Immunofluorescence microscopy examination of the dermal-epidermal junction in the patient's skin revealed near-normal intensity staining with an antitype VII collagen antibody (LH7:2). Transmission electron microscopy showed a reduced number of thin, poorly-formed anchoring fibrils. PCR amplification of genomic DNA, followed by heteroduplex analysis, and nucleotide sequencing demonstrated that the patient was a compound heterozygote for a nonsense mutation (E2858X) within the NC-2 domain of type VII collagen and a missense mutation (G2576R) within the type VII collagen triple helix. Both mutations were verified by restriction endonuclease digestion. Information about these mutations advances our understanding of genotype-phenotype correlations in dystrophic epidermolysis bullosa, and further delineates the mechanisms involved in dermal-epidermal dysadhesion.
Collapse
Affiliation(s)
- H Shimizu
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
| | | | | | | | | |
Collapse
|
18
|
Prenatal Diagnosis for Recessive Dystrophic Epidermolysis Bullosa in 10 Families by Mutation and Haplotype Analysis in the Type VII Collagen Gene (COL7A1). Mol Med 1996. [DOI: 10.1007/bf03402203] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
|
19
|
Christiano AM, LaForgia S, Paller AS, McGuire J, Shimizu H, Uitto J. Prenatal diagnosis for recessive dystrophic epidermolysis bullosa in 10 families by mutation and haplotype analysis in the type VII collagen gene (COL7A1). Mol Med 1996; 2:59-76. [PMID: 8900535 PMCID: PMC2230038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Epidermolysis bullosa (EB) is a group of heritable diseases that manifest as blistering and erosions of the skin and mucous membranes. In the dystrophic forms of EB (DEB), the diagnostic hallmark is abnormalities in the anchoring fibrils, attachment structures beneath the cutaneous basement membrane zone. The major component of anchoring fibrils is type VII collagen, and DEB has been linked to the type VII collagen gene (COL7A1) at 3p21, with no evidence for locus heterogeneity. Due to life-threatening complications and significant long-term morbidity associated with the severe, mutilating form of recessive dystrophic EB (RDEB), there has been a demand for prenatal diagnosis from families with affected offspring. MATERIALS AND METHODS Intragenic polymorphisms in COL7A1 and flanking microsatellite markers on chromosome 3p21, as well as detection of pathogenetic mutations in families, were used to perform PCR-based prenatal diagnosis from DNA obtained by chorionic villus sampling at 10-15 weeks or amniocentesis at 12-15 weeks gestation in 10 families at risk for recurrence of RDEB. RESULTS In nine cases, the fetus was predicted to be normal or a clinically unaffected carrier of a mutation in one allele. These predictions have been validated in nine cases by the birth of a healthy child. In one case, an affected fetus was predicted, and the diagnosis was confirmed by fetal skin biopsy. CONCLUSIONS DNA-based prenatal diagnosis of RDEB offers an early, expedient method of testing which will largely replace the previously available invasive fetal skin biopsy at 18-20 weeks gestation.
Collapse
Affiliation(s)
- A M Christiano
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Philadelphia, PA 19107, USA
| | | | | | | | | | | |
Collapse
|
20
|
Dunnill MG, Rodeck CH, Richards AJ, Atherton D, Lake BD, Petrou M, Eady RA, Pope FM. Use of type VII collagen gene (COL7A1) markers in prenatal diagnosis of recessive dystrophic epidermolysis bullosa. J Med Genet 1995; 32:749-50. [PMID: 8544200 PMCID: PMC1051681 DOI: 10.1136/jmg.32.9.749] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Generalised recessive dystrophic epidermolysis bullosa (EB) is a severe inherited disease in which patients suffer from blistering and scarring of the skin and mucous membranes after minor mechanical trauma. Tight genetic linkage has been established to the type VII collagen gene (COL7A1) at 3p21, with no evidence of locus heterogeneity. Several COL7A1 mutations have now been identified in recessive dystrophic EB patients. Prenatal diagnosis has been performed by examination of a fetal skin biopsy taken at about 16 weeks' gestation, and relies on identification of characteristic ultrastructural and immunohistochemical changes. We have now achieved a first trimester prenatal diagnosis using intragenic and flanking COL7A1 markers in a pregnancy at risk for recessive dystrophic EB. Segregation of the informative markers predicted the baby would be an unaffected carrier. The pregnancy continued to term and a healthy baby was born, confirming this result.
Collapse
Affiliation(s)
- M G Dunnill
- St John's Institute of Dermatology, St Thomas's Hospital, London, UK
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Affiliation(s)
- M G Dunnill
- St John's Institute of Dermatology, St Thomas' Hospital, London, UK
| | | |
Collapse
|
22
|
Hovnanian A, Hilal L, Blanchet-Bardon C, Bodemer C, de Prost Y, Stark CA, Christiano AM, Dommergues M, Terwilliger JD, Izquierdo L. DNA-based prenatal diagnosis of generalized recessive dystrophic epidermolysis bullosa in six pregnancies at risk for recurrence. J Invest Dermatol 1995; 104:456-61. [PMID: 7706758 DOI: 10.1111/1523-1747.ep12605893] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Linkage analyses in generalized recessive dystrophic epidermolysis bullosa (RDEB) have implicated the type VII collagen gene (COL7A1), which encodes the major component of anchoring fibrils, and recent identification of COL7A1 mutations has provided direct evidence for COL7A1 defects underlying RDEB. In this study, COL7A1 gene analysis was used to successfully perform first-trimester prenatal diagnosis in six families at risk for recurrence of the disease. In four families, three affected with the most severe variant of RDEB (the Hallopeau-Siemens form, HS-RDEB) and one with generalized nonmutilating RDEB, prenatal diagnosis was established by linkage analysis using polymerase chain reaction-based detection of PvuII and AluI intragenic restriction fragment length polymorphism. In two other HS-RDEB families, prenatal diagnosis was carried out by direct detection of mutations in COL7A1, using denaturing gradient gel electrophoresis analysis of polymerase chain reaction-amplified genomic fragments. Analysis of fetal DNA from chorionic villus biopsy or from amniotic fluid cells showed that the fetus had inherited at least one normal COL7A1 allele in all cases. Therefore, the fetus was predicted to be unaffected in the six pregnancies, and this has been confirmed in the newborn infants. Genotype analysis with COL7A1 polymorphic markers, or direct COL7A1 mutation detection in families at risk for the disease, represent early and rapid diagnostic alternatives to second-trimester evaluation of fetal skin samples, and thus offer a major advance in prenatal diagnosis of this life-threatening form of epidermolysis bullosa.
Collapse
Affiliation(s)
- A Hovnanian
- Laboratory of Biochemistry, INSERM U.91, Hôpital Henri Mondor, Créteil, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Eady RA, Dunnill MG. Epidermolysis bullosa: hereditary skin fragility diseases as paradigms in cell biology. Arch Dermatol Res 1994; 287:2-9. [PMID: 7537032 DOI: 10.1007/bf00370710] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Recent research into the molecular basis of epidermolysis bullosa has provided a unique insight into a variety of mechanisms in normal cell biology, such as cell-matrix interactions, and has uncovered an excellent model for studies on keratin intermediate filaments. The simplex forms of epidermolysis bullosa are caused by mutations in the genes for the basal epidermal keratins, K5 and K14. Most mutations affect highly conserved parts of the molecules, illustrating their importance in normal keratin filament assembly and integrity. Mutations in corresponding regions of the differentiation-associated keratins, K1 and K10 can also occur in epidermolytic ichthyosis. Both recessive and dominant forms of dystrophic epidermolysis bullosa result from mutations in an anchoring fibril collagen gene, COL7A1. Junctional epidermolysis bullosa is caused by mutations in the genes encoding different chains of the novel laminin isoform, nicein/kalinin, also known as laminin 5, which is associated with the anchoring filament-hemidesmosome complex of the basement membrane zone. These recent findings strengthen the evidence for the role of nicein/kalinin and type VII collagen in adherence and stabilization of the dermo-epidermal junction.
Collapse
Affiliation(s)
- R A Eady
- Department of Cell Pathology, St John's Institute of Dermatology, St. Thomas's Hospital, London, UK
| | | |
Collapse
|