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    A Novel Homozygous 9385 bp Deletion in the FERMT1 (KIND1) Gene in a Malaysian Family with Kindler Epidermolysis bullosa and a Review of Large Deletions
    (MDPI AG, 2025-04-29)
    Alfred Klausegger
    ;
    Fabian Leditzky
    ;
    Susanne Krämer
    ;
    ;
    Kindler Epidermolysis bullosa (KEB; OMIM 173650) is a rare autosomal recessive genodermatosis characterized by bullous poikiloderma and photosensitivity. Additional presentations include blistering, poor wound healing, skin atrophy, and increased risk of skin cancer. Most cases of KEB result from aberrations in the FERMT1 (Fermitin family member 1) gene encoding kindlin-1 and include nonsense, frameshift, splicing, and missense variants. Large deletion variants have been reported in nine cases to date. Most variants are predicted to lead to premature termination of translation and to loss of kindlin-1 function. In this study, we report on a 33-year-old male patient who presented with typical clinical manifestations of KEB. As routine molecular testing failed to obtain a diagnosis, Next Generation Sequencing (NGS) of an Epidermolysis Bullosa (EB)-specific panel was carried out followed by the determination of the deletion breakpoints and verification at the mRNA and protein levels. This approach revealed a new large homozygous deletion of ~9.4 kb in the FERMT1 gene involving exons 7 to 9. Finally, we performed a literature review on large FERMT1 deletions. The deletion is predicted to skip exons 7 to 9 within the mRNA, which results in a frameshift. The patient’s phenotype is likely caused by the resulting truncated and non-functioning protein. Our report further enriches the spectrum of FERMT1 gene variants to improve genotype–phenotype correlations.
      1
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    Novel and recurrent COL7A1 mutations in Chilean patients with dystrophic epidermolysis bullosa
    (2012)
    Fernando A. Rodríguez
    ;
    María José Gana
    ;
    ;
    Gisela Zillmann
    ;
    Susanne M. Krämer
      1Scopus© Citations 17
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    Novel variants impairing Sp1 transcription factor binding in the COL7A1 promoter cause mild cases of recessive dystrophic epidermolysis bullosa
    (Springer Science and Business Media LLC, 2024-12-05)
    Nathalie Pironon
    ;
    Artyom Gasparyan
    ;
    ;
    Sabine Duchatelet
    ;
    Kristina Hovhannesyan
    <jats:title>Abstract</jats:title><jats:p>Recessive dystrophic epidermolysis bullosa (RDEB) is a rare and most often severe genodermatosis characterized by recurrent blistering and erosions of the skin and mucous membranes after minor trauma, leading to major local and systemic complications. RDEB is caused by loss-of-function mutations in <jats:italic>COL7A1</jats:italic> encoding type VII collagen (C7), the main component of anchoring fibrils which form attachment structures stabilizing the cutaneous basement membrane zone. Most of the previously reported <jats:italic>COL7A1</jats:italic> mutations are located in the coding or intronic regions. We describe 6 patients with localized or intermediate RDEB for whom one recessive pathogenic variant in the coding region and a second variant in the <jats:italic>COL7A1</jats:italic> promoter were identified. These substitutions, three of which are novel, are localized in two Sp1 binding sites of the promoter region. DNA pull-down assay showed a drastic reduction of Sp1 binding consistent with a dramatic decrease in <jats:italic>COL7A1</jats:italic> transcript and almost undetectable C7 protein levels. Our results reveal that mutations in the <jats:italic>COL7A1</jats:italic> promoter on the background of a null allele can underlie localized or intermediate RDEB. They further emphasize the functional importance of Sp1 motifs in the proximal <jats:italic>COL7A1</jats:italic> promoter which should be carefully investigated for regulatory mutations in the case of RDEB with only one pathogenic variant identified in the coding or intronic regions.</jats:p>
      5Scopus© Citations 2
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      2
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    Outcomes and Predictors for Re-stenosis of Esophageal Stricture in Epidermolysis Bullosa: A Multicenter Cohort Study
    (2020)
    Elena Pope
    ;
    Mark Mansour
    ;
    Maria Berseneva
    ;
    Carmen Liy-Wong
    ;
    Julio Salas
      16Scopus© Citations 14
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    Case Report: Crown Resorption in a Patient With Junctional Epidermolysis Bullosa and Amelogenesis Imperfecta With LAMB3 Gene Mutations
    (2021)
    Blanca Urzúa
    ;
    Susanne Krämer
    ;
    Irene Morales-Bozo
    ;
    Claudia Camacho
    ;
    <jats:p><jats:bold>Background:</jats:bold> Epidermolysis bullosa (EB) corresponds to a series of conditions characterized by extreme fragility of the skin and/or mucous membranes. Of the four main types of EB, junctional EB (JEB) is the most associated with alterations in the teeth. The purposes of this study were to determine the clinical, histopathological, and ultrastructural characteristics of teeth with amelogenesis imperfecta (AI) in a patient with JEB, and compare them with control teeth, and correlate the findings with the mutations present in the patient.</jats:p><jats:p><jats:bold>Case Report:</jats:bold> The study was conducted on a 10-year-old patient with JEB carrier of two recessive mutations in the <jats:italic>LAMB3</jats:italic> gene and absence of the laminin-332 protein (LM-332), determined by immunofluorescence on a skin biopsy. The patient presents hypoplastic AI with very thin and yellow-brown colored enamel. Extraction of two permanent molars was performed due to pain and soft tissue covering the crown, resembling pulp polyp or hyperplastic gingiva. Light and scanning electron microscopy (SEM) revealed very thin enamel varying from complete absence to 60 μm, absence of normal prismatic structure, and presence of a cross-banding with a laminated appearance. The histopathological study revealed granulation tissue causing external crown resorption.</jats:p><jats:p><jats:bold>Conclusion:</jats:bold> Although coronary resorption has been reported in patients with syndromic and non-syndromic AI, this is the first clinicopathological report of coronary resorption in partially erupted teeth in patients with JEB with mutations in the <jats:italic>LAMB3</jats:italic> gene and hypoplastic AI. In patients with this condition, the presence of partially erupted teeth with soft tissue covering part of the crown, without a periodontal pocket, and with a radiographic image of partial coronal radiolucency should lead to suspicion of external coronary resorption.</jats:p>
      3Scopus© Citations 6
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    Maintenance of chronicity signatures in fibroblasts isolated from recessive dystrophic epidermolysis bullosa chronic wound dressings under culture conditions
    (2023) ;
    Evelyng Catalán
    ;
    Gabriel Garrido
    ;
    Pilar Morandé
    ;
    <jats:title>Abstract</jats:title><jats:sec> <jats:title>Background</jats:title> <jats:p>Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a rare inherited skin disease caused by variants in the <jats:italic>COL7A1</jats:italic> gene, coding for type VII collagen (C7), an important component of anchoring fibrils in the basement membrane of the epidermis. RDEB patients suffer from skin fragility starting with blister formation and evolving into chronic wounds, inflammation and skin fibrosis, with a high risk of developing aggressive skin carcinomas. Restricted therapeutic options are limited by the lack of in vitro models of defective wound healing in RDEB patients.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>In order to explore a more efficient, non-invasive in vitro model for RDEB studies, we obtained patient fibroblasts derived from discarded dressings) and examined their phenotypic features compared with fibroblasts derived from non-injured skin of RDEB and healthy-donor skin biopsies. Our results demonstrate that fibroblasts derived from RDEB chronic wounds (RDEB-CW) displayed characteristics of senescent cells, increased myofibroblast differentiation, and augmented levels of TGF-β1 signaling components compared to fibroblasts derived from RDEB acute wounds and unaffected RDEB skin as well as skin from healthy-donors. Furthermore, RDEB-CW fibroblasts exhibited an increased pattern of inflammatory cytokine secretion (IL-1β and IL-6) when compared with RDEB and control fibroblasts. Interestingly, these aberrant patterns were found specifically in RDEB-CW fibroblasts independent of the culturing method, since fibroblasts obtained from dressing of acute wounds displayed a phenotype more similar to fibroblasts obtained from RDEB normal skin biopsies.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Our results show that in vitro cultured RDEB-CW fibroblasts maintain distinctive cellular and molecular characteristics resembling the inflammatory and fibrotic microenvironment observed in RDEB patients’ chronic wounds. This work describes a novel, non-invasive and painless strategy to obtain human fibroblasts chronically subjected to an inflammatory and fibrotic environment, supporting their use as an accessible model for in vitro studies of RDEB wound healing pathogenesis. As such, this approach is well suited to testing new therapeutic strategies under controlled laboratory conditions.</jats:p> </jats:sec>
      1Scopus© Citations 11
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    Patients suffering from dystrophic epidermolysis bullosa are prone to developing autoantibodies against skin proteins: A longitudinal confirmational study
    (2024)
    J. Bremer
    ;
    H. H. Pas
    ;
    G. F. H. Diercks
    ;
    H. J. Meijer
    ;
    S. M. van der Molen
    <jats:title>Abstract</jats:title><jats:p>Epidermolysis bullosa (EB) is a heritable skin blistering disease caused by variants in genes coding for proteins that secure cell–cell adhesion and attachment of the epidermis to the dermis. Interestingly, several proteins involved in inherited EB are also associated with autoimmune blistering diseases (AIBD). In this study, we present a long‐term follow‐up of 15 patients suffering from recessive dystrophic or junctional EB. From these patients, 62 sera were analysed for the presence of autoantibodies associated with AIBD. We show that patients suffering from recessive dystrophic EB (RDEB) are more susceptible to developing autoantibodies against skin proteins than patients suffering from junctional EB (70% vs. 20%, respectively). Interestingly, no correlation with age was observed. Most patients showed reactivity to Type XVII collagen/linear IgA bullous dermatosis autoantigen (<jats:italic>n</jats:italic> = 5; 33%), followed by BP230 (<jats:italic>n</jats:italic> = 4; 27%), Type VII collagen (<jats:italic>n</jats:italic> = 4; 27%) and laminin‐332 (<jats:italic>n</jats:italic> = 1; 7%). The pathogenicity of these autoantibodies remains a subject for future experiments.</jats:p>
      1Scopus© Citations 3