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CRISPR/Cas9-based targeted genome editing for correction of recessive dystrophic epidermolysis bullosa using iPS cells. Proc Natl Acad Sci U S A 2019; 116:26846-26852. [PMID: 31818947 DOI: 10.1073/pnas.1907081116] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Recessive dystrophic epidermolysis bullosa (RDEB) is a severe inherited skin disorder caused by mutations in the COL7A1 gene encoding type VII collagen (C7). The spectrum of severity depends on the type of mutation in the COL7A1 gene. C7 is the major constituent of anchoring fibrils (AFs) at the basement membrane zone (BMZ). Patients with RDEB lack functional C7 and have severely impaired dermal-epidermal stability, resulting in extensive blistering and open wounds on the skin that greatly affect the patient's quality of life. There are currently no therapies approved for the treatment of RDEB. Here, we demonstrated the correction of mutations in exon 19 (c.2470insG) and exon 32 (c.3948insT) in the COL7A1 gene through homology-directed repair (HDR). We used the clustered regulatory interspaced short palindromic repeats (CRISPR) Cas9-gRNAs system to modify induced pluripotent stem cells (iPSCs) derived from patients with RDEB in both the heterozygous and homozygous states. Three-dimensional human skin equivalents (HSEs) were generated from gene-corrected iPSCs, differentiated into keratinocytes (KCs) and fibroblasts (FBs), and grafted onto immunodeficient mice, which showed normal expression of C7 at the BMZ as well as restored AFs 2 mo postgrafting. Safety assessment for potential off-target Cas9 cleavage activity did not reveal any unintended nuclease activity. Our findings represent a crucial advance for clinical applications of innovative autologous stem cell-based therapies for RDEB.
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Bremer J, van der Heijden EH, Eichhorn DS, Meijer R, Lemmink HH, Scheffer H, Sinke RJ, Jonkman MF, Pasmooij AMG, Van den Akker PC. Natural Exon Skipping Sets the Stage for Exon Skipping as Therapy for Dystrophic Epidermolysis Bullosa. MOLECULAR THERAPY. NUCLEIC ACIDS 2019; 18:465-475. [PMID: 31670143 PMCID: PMC6831832 DOI: 10.1016/j.omtn.2019.09.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 02/04/2023]
Abstract
Dystrophic epidermolysis bullosa (DEB) is a devastating blistering disease affecting skin and mucous membranes. It is caused by pathogenic variants in the COL7A1 gene encoding type VII collagen, and can be inherited dominantly or recessively. Recently, promising proof-of-principle has been shown for antisense oligonucleotide (AON)-mediated exon skipping as a therapeutic approach for DEB. However, the precise phenotypic effect to be anticipated from exon skipping, and which patient groups could benefit, is not yet clear. To answer these questions, we studied new clinical and molecular data on seven patients from the Dutch EB registry and reviewed the literature on COL7A1 exon skipping variants. We found that phenotypes associated with dominant exon skipping cannot be distinguished from phenotypes caused by other dominant DEB variants. Recessive exon skipping phenotypes are generally relatively mild in the spectrum of recessive DEB. Therefore, for dominant DEB, AON-mediated exon skipping is unlikely to ameliorate the phenotype. In contrast, the overall severity of phenotypes associated with recessive natural exon skipping pivots toward the milder end of the spectrum. Consequently, we anticipate AON-mediated exon skipping for recessive DEB caused by bi-allelic null variants should lead to a clinically relevant improvement of this devastating phenotype.
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Affiliation(s)
- Jeroen Bremer
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Dermatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
| | - Elisabeth H van der Heijden
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Daryll S Eichhorn
- Department of Dermatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Rowdy Meijer
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Henny H Lemmink
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Hans Scheffer
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Richard J Sinke
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Marcel F Jonkman
- Department of Dermatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Anna M G Pasmooij
- Department of Dermatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Peter C Van den Akker
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Dermatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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Real-time PCR Detection of the Recessive Dystrophic Epidermolysis Bullosa-associated c.2470insG Mutation in Unrelated Mexican Families. Arch Med Res 2014; 45:596-9. [DOI: 10.1016/j.arcmed.2014.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/25/2014] [Indexed: 01/11/2023]
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Liy-Wong C, Cepeda-Valdes R, Salas-Alanis JC. Epidermolysis bullosa care in Mexico. Dermatol Clin 2010; 28:393-4, xiii. [PMID: 20447510 DOI: 10.1016/j.det.2010.02.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epidermolysis bullosa (EB) in Mexico continues to be a rare genodermatosis that is still unknown for most of the health care professionals in the country. The spirit of DebRA MEXICO was born in 1994 when the Mexican health care team started to see patients with the main purpose to provide medical care, genetic counseling, and advice to patients with EB and their families; to promote collaboration and exchange information among people with EB; to research and find new therapeutic approaches; and finally, to diffuse knowledge and raise awareness of the issues of EB in general public and health care professionals.
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Affiliation(s)
- Carmen Liy-Wong
- Department of Dermatology, Hospital Universitario Dr Jose E. Gonzalez UANL, Monterrey, Nuevo León, México
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Massé M, Cserhalmi-Friedman PB, Falanga V, Celebi JT, Martinez-Mir A, Christiano AM. Identification of novel type VII collagen gene mutations resulting in severe recessive dystrophic epidermolysis bullosa. Clin Exp Dermatol 2005; 30:289-93. [PMID: 15807692 DOI: 10.1111/j.1365-2230.2005.01763.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, we studied the proband in a small nuclear family of Chinese and Dutch/German descent and identified two novel mutations in the type VII collagen gene leading to recessive dystrophic epidermolysis bullosa, Hallopeau-Siemens variant (HS-RDEB). The maternal mutation is a single base pair deletion of a cytosine nucleotide in exon 26, designated 3472delC, resulting in a frameshift and a premature termination codon (PTC) within the same exon, 7 bp downstream of the site of the mutation. The paternal mutation is a G-->A transition located at the 5' donor splice site within intron 51, designated IVS51 + 1G-->A. This mutation leads to the activation of a cryptic splice site, 32 bp downstream of the mutation site and to subsequent aberrant out-of-frame splicing, resulting in two alternative mRNA transcripts and a downstream PTC. To our knowledge, these two mutations have not been previously reported. These findings extend the body of evidence for compound heterozygous mutations leading to HS-RDEB and provide the basis for prenatal diagnosis in this family.
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Affiliation(s)
- M Massé
- Department of Dermatology, Columbia University, New York, USA
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Jiang W, Sun Y, Li S, Chen XX, Bu DF, Zhu XJ. Two novel heterozygous mutations in COL7A1 in a Chinese patient with recessive dystrophic epidermolysis bullosa of Hallopeau-Siemens type. Br J Dermatol 2005; 152:1357-9. [PMID: 15949010 DOI: 10.1111/j.1365-2133.2005.06638.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- W Jiang
- Department of Dermatology, Peking University First Hospital, Beijing 10034, China.
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Reyes ML, Cattani A, Gajardo H, García C, McGrath JA, Palisson F. Bone metabolism in children with epidermolysis bullosa. J Pediatr 2002; 140:467-9. [PMID: 12006964 DOI: 10.1067/mpd.2002.123287] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We evaluated bone mineral density, vitamin D status, and biochemical markers of bone turnover in seven children with epidermolysis bullosa (EB). Four had osteopenia (Z score, -1.5) and four 25(OH) vitamin D <34 nmol/L (14 ng/mL), two of which had hyperparathyroidism. Children with severe EB should have evaluation of bone metabolism.
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Affiliation(s)
- M Loreto Reyes
- Pediatrics Department, Endocrine Unit, Pontificia Universidad Católica de Chile, Instituto de Nutrición y Tecnología en Alimentos, Santiago, Chile
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Abstract
BACKGROUND Type VII collagen gene (COL7A1) mutations are the cause of dystrophic epidermolysis bullosa (DEB), but most mutations are specific to individual families, and there are limited data on the nature of COL7A1 mutations in certain ethnic populations. OBJECTIVE To determine the molecular basis of DEB in Hispanic Mexican patients. METHODS Patients were recruited through a newly established support group, Fundacion DEBRA Mexico. Molecular analysis was performed by polymerase chain reaction (PCR) of genomic DNA using COL7A1-specific primers, heteroduplex analysis, and direct nucleotide sequencing. RESULTS Fifty-nine of a possible 67 COL7A1 mutations (88%) were identified in 36 affected individuals (31 recessive, five dominant) in 21 families. Recessive mutations included six frameshift mutations, four silent glycine substitutions, and two splice-site mutations. Dominant mutations comprised a de novo glycine substitution and an internal deletion. Conclusions This study establishes the molecular basis of DEB in a group of Mexican patients. Only two of the mutations have been identified previously in other ethnic groups; the remainder are specific to this population. These new data are helpful in facilitating the accurate diagnosis of DEB subtype, in improving genetic counseling, and in providing further insight into the pathophysiology of this mechanobullous disease.
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Affiliation(s)
- J C Salas-Alanis
- Servicios Médicos de la Universidad Autonóma de Nuevo León, Monterrey, Mexico.
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Whittock NV, Ashton GH, Mohammedi R, Mellerio JE, Mathew CG, Abbs SJ, Eady RA, McGrath JA. Comparative mutation detection screening of the type VII collagen gene (COL7A1) using the protein truncation test, fluorescent chemical cleavage of mismatch, and conformation sensitive gel electrophoresis. J Invest Dermatol 1999; 113:673-86. [PMID: 10504458 DOI: 10.1046/j.1523-1747.1999.00732.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mutations in the type VII collagen gene, COL7A1, give rise to the blistering skin disease, dystrophic epidermolysis bullosa. We have developed two new mutation detection strategies for the screening of COL7A1 mutations in patients with dystrophic epidermolysis bullosa and compared them with an established protocol using conformational sensitive gel electrophoresis. The first strategy consisted of an RNA based protein truncation test that amplified the entire coding region in only four overlapping nested reverse transcriptase-polymerase chain reaction assays. These fragments were transcribed and translated in vitro and analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We have used the protein truncation test procedure to characterize 15 truncating mutations in 13 patients with severe recessive dystrophic epidermolysis bullosa yielding a detection sensitivity of 58%. The second strategy was a DNA-based fluorescent chemical cleavage of mismatch (fl-CCM) procedure that amplified the COL7A1 gene in 21 polymerase chain reaction assays. Mismatches, formed between patient and control DNA, were identified using chemical modification and cleavage of the DNA. We have compared fl-CCM with conformational sensitive gel electrophoresis by screening a total of 50 dominant and recessive dystrophic epidermolysis bullosa patients. The detection sensitivity for fl-CCM was 81% compared with 75% for conformational sensitive gel electrophoresis (p = 0.37 chi2-test). Using a combination of the three techniques we have screened 93 dystrophic epidermolysis bullosa patients yielding an overall sensitivity of 87%, detecting 79 different mutations, 57 of which have not been reported previously. Comparing all three approaches, we believe that no single method is consistently better than the others, but that the fl-CCM procedure is a sensitive, semiautomated, high throughput system that can be recommended for COL7A1 mutation detection.
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Affiliation(s)
- N V Whittock
- Department of Cell and Molecular Pathology, St John's Institute of Dermatology, St Thomas' Hospitals' Medical School, London, UK.
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McGrath JA, Ashton GH, Mellerio JE, Salas-Alanis JC, Swensson O, McMillan JR, Eady RA. Moderation of phenotypic severity in dystrophic and junctional forms of epidermolysis bullosa through in-frame skipping of exons containing non-sense or frameshift mutations. J Invest Dermatol 1999; 113:314-21. [PMID: 10469327 DOI: 10.1046/j.1523-1747.1999.00709.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Non-sense mutations on both alleles of either the type VII collagen gene (COL7A1) or the genes encoding laminin 5 (LAMA3, LAMB3, or LAMC2) usually result in clinically severe forms of recessive dystrophic or junctional epidermolysis bullosa, respectively. In this study we assessed two unrelated families whose mutations in genomic DNA predicted severe recessive dystrophic epidermolysis bullosa or junctional epidermolysis bullosa phenotypes but in whom the manifestations were milder than expected. The recessive dystrophic epidermolysis bullosa patients had a homozygous single base-pair frameshift mutation in exon 19 of COL7A1 (2470insG). Clinically, there was generalized blistering but only mild scarring. Skin biopsy revealed positive type VII collagen immunoreactivity and recognizable anchoring fibrils. The junctional epidermolysis bullosa patients were compound heterozygotes for a frameshift/non-sense combination of mutations in exons 3 and 17 of LAMB3 (29insC/Q834X). These patients did not have the lethal form of junctional epidermolysis bullosa but, as adults, displayed the milder generalized atrophic benign epidermolysis bullosa variant. There was undetectable laminin 5 staining at the dermal-epidermal junction using an antibody to the beta3 chain, but faintly positive alpha3 and gamma2 chain labeling, and there was variable hypoplasia of hemidesmosomes. To explain the milder recessive dystrophic epidermolysis bullosa and junctional epidermolysis bullosa phenotypes in these families, reverse transcription-polymerase chain reaction, using RNA extracted from frozen skin, was able to provide evidence for some rescue of mutant mRNA transcripts with restoration of the open- reading frame. In the recessive dystrophic epidermolysis bullosa patients, transcripts containing in-frame skipping of exon 19 of COL7A1 in the cDNA were detected, and in the junctional epidermolysis bullosa patients transcripts with in-frame skipping of exon 17 of LAMB3 were identified. The truncated proteins encoded by these transcripts are expected to lack certain critical domains involved in cell-matrix attachment, but may still be able to contribute to adhesion thereby moderating the severity of the skin blistering. This study shows the limitations in predicting phenotype in epidermolysis bullosa solely based on mutation analysis of genomic DNA and emphasizes the importance of immunohistochemistry, electron microscopy, and mRNA assessment as parallel investigations.
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Affiliation(s)
- J A McGrath
- 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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Mellerio JE, Salas-Alanis JC, Amaya-Guerra M, Tamez E, Ashton GH, Mohammedi R, Eady RA, McGrath JA. A recurrent frameshift mutation in exon 19 of the type VII collagen gene (COL7A1) in Mexican patients with recessive dystrophic epidermolysis bullosa. Exp Dermatol 1999; 8:22-9. [PMID: 10206718 DOI: 10.1111/j.1600-0625.1999.tb00344.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dystrophic epidermolysis bullosa (DEB) is an inherited blistering skin disorder caused by mutations in the type VII collagen gene (COL7A1). In this study, we determined the molecular basis of autosomal recessive DEB in a 19-year-old Hispanic Mexican woman by PCR amplification of genomic DNA, heteroduplex analysis, and automated sequencing of heteroduplex bandshifts. This approach revealed a homozygous frameshift mutation, 2470insG, in exon 19 of COL7A1 and resulted in attenuated basement membrane zone expression of type VII collagen, a reduced number of anchoring fibrils at the dermal-epidermal junction, and a sub-lamina densa level of blister formation. Clinically, the patient had widespread trauma-induced skin fragility and complete loss of the nails, but had less pseudosyndactyly of the fingers and toes and milder mucosal involvement compared to most patients with the generalized form of this genodermatosis. We also screened 7 other Hispanic-Mexican patients with recessive DEB, none of whom were known to be related to this individual, for the mutation 2470insG using heteroduplex analysis and direct sequencing and detected this mutation on 7/14 alleles. Haplotype analysis using intragenic COL7A1 and flanking polymorphisms and microsatellite markers revealed that all the mutant alleles had arisen on similar allelic backgrounds, consistent with propagation of a common Hispanic Mexican ancestral haplotype. In view of the high allelic frequency of the mutation 2470insG in the patients studied, we recommend initial screening for this mutation when attempting to identify the molecular pathology of recessive DEB in Hispanic Mexican patients.
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Affiliation(s)
- J E Mellerio
- Department of Cell and Molecular Pathology, St John's Institute of Dermatology, St Thomas's Hospital, London, UK
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