Inherited epidermolysis bullosa: updated recommendations on diagnosis and classification

Breaking Down Barriers: Epithelial Contributors to Monogenic IBD Pathogenesis

Monogenic causes of inflammatory bowel diseases (IBD) are increasingly being discovered. To date, much attention has been placed in those resulting from inborn errors of immunity. Therapeutic efforts have been largely focused on offering personalized immune modulation or curative bone marrow transplant for patients with IBD and underlying immune disorders. To date, less emphasis has been placed on monogenic causes of IBD that pertain to impairment of the intestinal epithelial barrier. Here, we provide a comprehensive review of monogenic causes of IBD that result in impaired intestinal epithelial barrier that are categorized into 6 important functions: (1) epithelial cell organization, (2) epithelial cell intrinsic functions, (3) epithelial cell apoptosis and necroptosis, (4) complement activation, (5) epithelial cell signaling, and (6) control of RNA degradation products. We illustrate how impairment of any of these categories can result in IBD. This work reviews the current understanding of the genes involved in maintaining the intestinal barrier, the inheritance patterns that result in dysfunction, features of IBD resulting from these disorders, and pertinent translational work in this field.

Genotype-Phenotype Correlation in Junctional Epidermolysis Bullosa: Signposts to Severity

Junctional epidermolysis bullosa (JEB) is a rare autosomal recessive genodermatosis with a broad spectrum of phenotypes. Current genotype-phenotype paradigms are insufficient to accurately predict JEB subtype and characteristics from genotype, particularly for splice site variants, which account for over a fifth of disease-causing variants in JEB. This study evaluated the genetic and clinical findings from a JEB cohort, investigating genotype-phenotype correlations through bioinformatic analyses and comparison with previously reported variants. Eighteen unique variants in LAMB3, LAMA3, LAMC2, or COL17A1 were identified from 17 individuals. Seven had severe JEB, 9 had intermediate JEB, and 1 had laryngo-onycho-cutaneous syndrome. Seven variants were previously unreported. Deep phenotyping was completed for all intermediate JEB cases and demonstrated substantial variation between individuals. Splice site variants underwent analysis with SpliceAI, a state-of-the-art artificial intelligence tool, to predict resultant transcripts. Predicted functional effects included exon skipping and cryptic splice site activation, which provided potential explanations for disease severity and in most cases correlated with laminin-332 immunofluorescence. RT-PCR was performed for 1 case to investigate resultant transcripts produced from the splice site variant. This study expands the JEB genomic and phenotypic landscape. Artificial intelligence tools show potential for predicting the functional effects of splice site variants and may identify candidates for confirmatory laboratory investigation. Investigation of RNA transcripts will help to further elucidate genotype-phenotype correlations for novel variants.

Highly Efficient Ex Vivo Correction of COL7A1 through Ribonucleoprotein-Based CRISPR/Cas9 and Homology-Directed Repair to Treat Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare and severe genetic skin disease responsible for blistering of the skin and mucosa after minor trauma. RDEB is caused by a wide variety of variants in COL7A1 encoding type VII Collagen, the major component of anchoring fibrils that form key attachment structures for dermal-epidermal adherence. In this study, we achieved highly efficient COL7A1 editing in primary RDEB keratinocytes and fibroblasts from 2 patients homozygous for the c.6508C>T (p.Gln2170∗) variant through CRISPR/Cas9-mediated homology-directed repair. Three guide RNAs targeting the c.6508C>T variant or harboring sequences were delivered together with high-fidelity Cas9 as a ribonucleoprotein complex. Among them, one achieved 73% cleavage activity in primary RDEB keratinocytes and RDEB fibroblasts. Then, we treated RDEB keratinocytes and RDEB fibroblasts with this specific ribonucleoprotein complex and the corresponding donor template delivered as single-stranded oligodeoxynucleotide and achieved up to 58% of genetic correction as well as type VII Collagen rescue. Finally, grafting of corrected 3-dimensional skin onto nude mice induced re-expression and normal localization of type VII Collagen as well as anchoring fibril formation at the dermal-epidermal junction 5 and 10 weeks after grafting. With this promising nonviral approach, we achieved therapeutically relevant specific gene editing that could be applicable to all variants in exon 80 of COL7A1 in primary RDEB cells.

Lessons to Learn About the Misdiagnosis of a Rare Case in China: Bart Syndrome or Carmi Syndrome?

Objective

We report a case of Carmi Syndrome in a neonate.

Aim

To share our lessons in diagnosis of the case of Carmi Syndrome.

Case Report

Carmi Syndrome is an extremely rare autosomal recessive genetic disorder characterized the coexistence of pyloric atresia and junctional epidermolysis bullosa, and with aplasia cutis congenita in approximately 28% patients. In this case, a full-term male neonate was born to a G4P2+1L1 multipara through cesarean section delivery in hospital in a non-consanguineous marriage with 4000mL of II°meconium-stained amniotic fluid. He was found extensive skin loss over lower legs and other parts, with scattered blisters and bilateral microtia. Plain abdominal X-ray revealed a large gastric air bubble with no gas distally. The mother had an intrauterine fetal loss previously for reasons unknown. The dermatologist diagnosed the newborn with Bart Syndrome, while the pediatric surgeon diagnosed congenital pyloric atresia(CPA). The parents refused further treatment and the neonate passed away about 30 hours after birth.

Outcome

The neonate passed away about 30 hours after birth.

Conclusion

Lessons from this case:①.Rule out Carmi Syndrome in patients with PA, and differentiate Bart syndrome and Carmi Syndrome in patients with abnormal skin manifestations. ②. For rare and/or severe diseases, multidisciplinary teams(MDTs) should be establish. ③. Genetic counseling and prenatal diagnosis are necessary prior to subsequent childbearings. ④.Termination of pregnancy might be contemplated if certain indicators are revealed.

Beyond the Surface: A Narrative Review Examining the Systemic Impacts of Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare genetic disease resulting from inadequate type VII collagen (C7). Although recurrent skin blisters and wounds are the most apparent disease features, the impact of C7 loss is not confined to the skin and mucous membranes. RDEB is a systemic disease marred by chronic inflammation, fibrotic changes, pain, itch, and anemia, significantly impacting QOL and survival. In this narrative review, we summarize these systemic features of RDEB and promising research avenues to address them.

Epidermolysis Bullosa: Two rare case reports of COL7A1 and EBS-GEN SEV KRT14 variants with review of literature

EPIDERMOLYSIS

Bullosa is a rare hereditary skin condition that causes blisters. Genes encoding structural proteins at or near the dermal-epidermal junction are mutated recessively or dominantly, and this is the primary cause of EB. Herein, two Chinese boys were diagnosed with the condition, each with a different variant in a gene that serves as a reference for EB genetic counseling. Skincare significantly impacted their prognosis and quality of life.

CASE PRESENTATION

Two Chinese boys, with phenotypically normal parents, have been diagnosed with distinct blister symptoms, one with Dominant Dystrophic Epidermolysis Bullosa and the other with a severe form of Epidermolysis Bullosa Simplex. The first patient had a G-to-A variant in the COL7A1 allele, at nucleotide position 6163 which was named "G2055A". The proband is heterozygous for Dystrophic Epidermolysis Bullosa due to a COL7A1 allele with a glycine substitution at the triple helix domain. A similar variant has been discovered in his mother, indicating its potential transmission to future generations. Another patient had severe Epidermolysis Bullosa Simplex with a rare c.377T > A  variant resulting in substitution of amino acid p.Leu126Arg (NM_000526.5 (c.377T > G, p.Leu126Arg) in the Keratin 14 gene. In prior literature, Keratin 14 has been associated with an excellent prognosis. However, our patient with this infrequent variant tragically died from sepsis at 21 days old. There has been a reported occurrence of the variant only once.

CONCLUSION

Our study reveals that Epidermolysis Bullosa patients with COL7A1 c.6163G > A and KRT14 c.377T>A variants have different clinical presentations, with dominant forms of Dystrophic EB having milder phenotypes than recessive ones. Thus, the better prognosis in the c.6163G > A patient. Furthermore, c.377T>A patient was more prone to infection than the patient with c.6163G>A gene variant. Genetic testing is crucial for identifying the specific variant responsible and improving treatment options.

Evolution of genome diagnostics in epidermolysis bullosa: Unveiling the power of next-generation sequencing

BACKGROUND

Genome diagnostics is considered gold standard diagnostics for epidermolysis bullosa (EB), a phenotypically and genetically heterogeneous group of rare disorders characterized by blistering and wounding of mucocutaneous tissues. EB is caused by pathogenic variants in genes encoding proteins of the dermo-epidermal junction. Accurate genetic diagnosis of EB is crucial for prognostication, counselling and precision-medicine. Genome diagnostics for EB started in 1991 with the introduction of Sanger sequencing (SS), analysing one gene at a time. In 2013, SS was superseded by next-generation sequencing (NGS), that allow for high-throughput sequencing of multiple genes in parallel. Several studies have shown a beneficial role for NGS in EB diagnostics, but its true benefit has not been quantified.

OBJECTIVES

To determine the benefit of NGS in EB by systematically evaluating the performance of different genome diagnostics used over time based on robust data from the Dutch EB Registry.

METHODS

The diagnostic performances of SS and NGS were systematically evaluated in a retrospective observational study including all index cases with a clinical diagnosis of EB in whom genome diagnostics was performed between 01 January 1994 and 01 January 2022 (n = 308), registered at the Dutch EB Expertise Centre.

RESULTS

Over time, a genetic diagnosis was made in 289/308 (94%) EB cases. The diagnostic yield increased from 89% (SS) to 95% (NGS). Most importantly, NGS significantly reduced diagnostic turnaround time (39 days vs. 211 days, p < 0.001). The likelihood of detecting variants of uncertain significance and additional findings increased from 5% and 1% (SS) to 22% and 13% (NGS) respectively.

CONCLUSIONS

Our study quantifies the benefit of NGS-based methods and demonstrate they have had a major impact on EB diagnostics through an increased diagnostic yield and a dramatically decreased turnaround time (39 days). Although our diagnostic yield is high (95%), further improvement of genome diagnostics is urgently needed to provide a genetic diagnosis in all EB patients.

Gene-edited cells: novel allogeneic gene/cell therapy for epidermolysis bullosa

Epidermolysis bullosa (EB) is a group of rare genetic skin fragility disorders, which are hereditary. These disorders are associated with mutations in at least 16 genes that encode components of the epidermal adhesion complex. Currently, there are no effective treatments for this disorder. All current treatment approaches focus on topical treatments to prevent complications and infections. In recent years, significant progress has been achieved in the treatment of the severe genetic skin blistering condition known as EB through preclinical and clinical advancements. Promising developments have emerged in the areas of protein and cell therapies, such as allogeneic stem cell transplantation; in addition, RNA-based therapies and gene therapy approaches have also become a reality. Stem cells obtained from embryonic or adult tissues, including the skin, are undifferentiated cells with the ability to generate, maintain, and replace fully developed cells and tissues. Recent advancements in preclinical and clinical research have significantly enhanced stem cell therapy, presenting a promising treatment option for various diseases that are not effectively addressed by current medical treatments. Different types of stem cells such as primarily hematopoietic and mesenchymal, obtained from the patient or from a donor, have been utilized to treat severe forms of diseases, each with some beneficial effects. In addition, extensive research has shown that gene transfer methods targeting allogeneic and autologous epidermal stem cells to replace or correct the defective gene are promising. These methods can regenerate and restore the adhesion of primary keratinocytes in EB patients. The long-term treatment of skin lesions in a small number of patients has shown promising results through the transplantation of skin grafts produced from gene-corrected autologous epidermal stem cells. This article attempts to summarize the current situation, potential development prospects, and some of the challenges related to the cell therapy approach for EB treatment.

Stop codon readthrough as a treatment option for epidermolysis bullosa-Where we are and where we are going

In the context of rare genetic diseases caused by nonsense mutations, the concept of induced stop codon readthrough (SCR) represents an attractive avenue in the ongoing search for improved treatment options. Epidermolysis bullosa (EB)-exemplary for this group of diseases-describes a diverse group of rare, blistering genodermatoses. Characterized by extreme skin fragility upon minor mechanical trauma, the most severe forms often result from nonsense mutations that lead to premature translation termination and loss of function of essential proteins at the dermo-epidermal junction. Since no curative interventions are currently available, medical care is mainly limited to alleviating symptoms and preventing complications. Complementary to attempts of gene, cell and protein therapy in EB, SCR represents a promising medical alternative. While gentamicin has already been examined in several clinical trials involving EB, other potent SCR inducers, such as ataluren, may also show promise in treating the hitherto non-curative disease. In addition to the extensively studied aminoglycosides and their derivatives, several other substance classes-non-aminoglycoside antibiotics and non-aminoglycoside compounds-are currently under investigation. The extensive data gathered in numerous in vitro experiments and the perspectives they reveal in the clinical setting will be discussed in this review.

Elevated expression of interleukin-6 (IL-6) and serum amyloid A (SAA) in the skin and the serum of recessive dystrophic epidermolysis bullosa: Skin as a possible source of IL-6 through Toll-like receptor ligands and SAA

The effect of persistent skin inflammation on extracutaneous organs and blood is not well studied. Patients with recessive dystrophic epidermolysis bullosa (RDEB), a severe form of the inherited blistering skin disorder, have widespread and persistent skin ulcers, and they develop various complications including anaemia, hyperglobulinaemia, hypoalbuminaemia and secondary amyloidosis. These complications are associated with the bioactivities of IL-6, and the development of secondary amyloidosis requires the persistent elevation of serum amyloid A (SAA) level. We found that patients with RDEB had significantly higher serum levels of IL-6 and SAA compared to healthy volunteers and patients with psoriasis or atopic dermatitis. Both IL-6 and SAA were highly expressed in epidermal keratinocytes and dermal fibroblasts of the skin ulcer lesions. Keratinocytes and fibroblasts surrounding the ulcer lesions are continuously exposed to Toll-like receptor (TLR) ligands, pathogen-associated and damage-associated molecular pattern molecules. In vitro, TLR ligands induced IL-6 expression via NF-κB in normal human epidermal keratinocytes (NHEKs) and dermal fibroblasts (NHDFs). SAA further induced the expression of IL-6 via TLR1/2 and NF-κB in NHEKs and NHDFs. The limitation of this study is that NHEKs and NHDFs were not derived from RDEB patients. These observations suggest that TLR-mediated persistent skin inflammation might increase the risk of IL-6-related systemic complications, including RDEB.

Efficacy of oral JAK1 or JAK1/2 inhibitor for treating refractory pruritus in dystrophic epidermolysis bullosa: A retrospective case series

Refractory pruritus is the most distressing, disease-related symptom in patients with dystrophic epidermolysis bullosa (DEB), inducing an itch-scratch-blister cycle. Chronic inflammation is a hallmark of DEB, thus upregulation of inflammatory cytokines and Janus kinase (JAK) signaling may play a role in DEB-related pruritus. We retrospectively reviewed the medical records of DEB patients with refractory pruritus who were treated with either baricitinib, a JAK1/2 inhibitor, or upadacitinib, a selective JAK1 inhibitor. Patients received baricitinib (4 mg) or upadacitinib (15 mg) once a day for 2-32 weeks. A total of 12 DEB patients (six recessive DEB and six dominant DEB) were included in this study. The mean±SD baseline pruritus visual analog scale (VAS) score was 7.5 ± 1.7. Upadacitinib or baricitinib treatment resulted in a rapid and sustained decrease in itch. Four out of 12 patients (33.3%) and seven out of 10 patients (70%) showed a decrease of at least 3 points in the pruritus VAS score from baseline at weeks 2 and 4, respectively. The mean percentage changes from baseline in pruritus VAS scores at weeks 2 and 4 were -42.9% and -52.7%, respectively. Subgroup analysis showed greater reductions in the pruritus VAS score in the baricitinib group (n = 5) compared to the upadacitinib group (n = 7), and in patients with epidermolysis bullosa pruriginosa (n = 3) compared to other subtypes of DEB (n = 9); however, these differences did not reach statistical significance. Three out of 10 (33.3%) patients showed at least a 2-point reduction in pain intensity from baseline at week 4. Eight out of 12 patients (66.7%) also showed a reduction in the number of new blisters, which correlated with a reduction in the pruritus score. No patient discontinued treatment because of serious adverse events. Our results suggest that JAK1 or JAK1/2 inhibitors could be a promising treatment option for DEB-related pruritus. Long-term safety should be assessed in future studies.

Allele-specific CRISPR-Cas9 editing of dominant epidermolysis bullosa simplex in human epidermal stem cells

Epidermolysis bullosa simplex (EBS) is a rare skin disease inherited mostly in an autosomal dominant manner. Patients display a skin fragility that leads to blisters and erosions caused by minor mechanical trauma. EBS phenotypic and genotypic variants are caused by genetic defects in intracellular proteins whose function is to provide the attachment of basal keratinocytes to the basement membrane zone and most EBS cases display mutations in keratin 5 (KRT5) and keratin 14 (KRT14) genes. Besides palliative treatments, there is still no long-lasting effective cure to correct the mutant gene and abolish the dominant negative effect of the pathogenic protein over its wild-type counterpart. Here, we propose a molecular strategy for EBS01 patient's keratinocytes carrying a monoallelic c.475/495del21 mutation in KRT14 exon 1. Through the CRISPR-Cas9 system, we perform a specific cleavage only on the mutant allele and restore a normal cellular phenotype and a correct intermediate filament network, without affecting the epidermal stem cell, referred to as holoclones, which play a crucial role in epidermal regeneration.

Dystrophic epidermolysis with dilation of esophageal stricture: A case report

Dystrophic epidermolysis bullosa (DEB) is a rare disease and the associated esophageal stricture is frequently complicated by the lack of clinical experience. The present study reported a very rare case of DEB in a 37-year-old male, who was admitted to Shenzhen Hospital (Shenzhen, China) due to an esophageal stricture. The patient received esophageal dilation under digital subtraction angiography. In this patient, dilation therapy was effective and safe. The patient underwent skin biopsies, and histological examination of the resected tissue specimens confirmed DEB diagnosis. The patient was followed up in the Department of Thoracic Surgery, Shenzhen Hospital, for 2 years without any recurrence of esophageal stricture. This is the first case report of dilation therapy in a very rare case of DEB with a satisfactory outcome, but the long-term efficacy needs further observation. In addition, the latest relevant literature was reviewed and it was found that this treatment is uncommonly reported, as is the condition.

Simple and affordable soft brace application in dystrophic epidermolysis bullosa patients

Background

Dystrophic epidermolysis bullosa (DEB) is a hereditary disease characterized by increased fragility of the epidermis and mucosa and is accompanied by blister formation following minor trauma. Repeated injuries cause contracture and scar formation, which can further result in hand deformity, leading to a decline in hand ability and a lower quality of life. In this study, after the scar release of patients' hands, we developed a new and practical portable soft support, and evaluated its efficacy in delaying the scar contracture of hands after operation.

Methods

According to the hand function scores, the patients were divided into two groups. Those with excellent and good grades were assigned to the open hand function group, and those with poor grades were allocated to the restricted hand function group. The primary conditions, the use of a postoperative soft brace, and some common factors in the two groups were compared to determine whether these parameters influence postoperative hand function.

Results

There were no significant differences in age, gender, body mass index, ADL assessment index, albumin concentration, hemoglobin concentration, fasting blood glucose level, prothrombin time, and activated partial thromboplastin time between the two groups (p > 0.05). In contrast, there was a significant difference between the two groups in the use of soft braces following the operation (p < 0.05). The odds ratio of patients fixed with a brace compared with patients not fixed with soft braces was 11.01.

Conclusions

Soft brace is a critical factor impacting the hand function of patients with dystrophic epidermolysis bullosa after scar contracture release in both hands. Indeed, a hand brace worn after the operation can delay the recurrence of scar contracture in both hands and offer patients a longer time to use their hands effectively. In addition, by restoring the appearance of patients' hands and some hand functions, patients' mental state and quality of life have been greatly improved.

MicroRNA-200b-mediated reversion of a spectrum of epithelial-to-mesenchymal transition states in recessive dystrophic epidermolysis bullosa squamous cell carcinomas

BACKGROUND

Cutaneous squamous cell carcinoma (SCC) is the leading cause of death in patients with recessive dystrophic epidermolysis bullosa (RDEB). However, the survival time from first diagnosis differs between patients; some tumours spread particularly fast, while others may remain localized for years. As treatment options are limited, there is an urgent need for further insights into the pathomechanisms of RDEB tumours, to foster therapy development and support clinical decision-making.

OBJECTIVES

To investigate differences in RDEB tumours of diverging aggressiveness at the molecular and phenotypic level, with a particular focus on epithelial-to-mesenchymal (EMT) transition states and thus microRNA-200b (miR-200b) as a regulator.

METHODS

Primary RDEB-SCC keratinocyte lines were characterized with respect to their EMT state. For this purpose, cell morphology was classified and the expression of EMT markers analysed using immunofluorescence, flow cytometry, semi-quantitative reverse transcriptase polymerase chain reaction and Western blotting. The motility of RDEB-SCC cells was determined and conditioned medium of RDEB-SCC cells was used to treat endothelial cells in an angiogenesis assay. In addition, we mined previously generated microRNA (miRNA) profiling data to identify a candidate with potential therapeutic relevance and performed transient miRNA transfection studies to investigate the candidate's ability to reverse EMT characteristics.

RESULTS

We observed high variability in EMT state in the RDEB-SCC cell lines, which correlated with in situ analysis of two available patient biopsies and respective clinical disease course. Furthermore, we identified miR-200b-3p to be downregulated in RDEB-SCCs, and the extent of deregulation significantly correlated with the EMT features of the various tumour lines. miR-200b-3p was reintroduced into RDEB-SCC cell lines with pronounced EMT features, which resulted in a significant increase in epithelial characteristics, including cell morphology, EMT marker expression, migration and angiogenic potential.

CONCLUSIONS

RDEB-SCCs exist in different EMT states and the level of miR-200b is indicative of how far an RDEB-SCC has gone down the EMT path. Moreover, the reintroduction of miR-200b significantly reduced mesenchymal features.

Health-related quality of life and clinical severity in people with epidermolysis bullosa - A proposal for assessing nutritional compromise by body mass index (Birmingham Epidermolysis Bullosa Severity Score)

INTRODUCTION AND OBJECTIVES

epidermolysis bullosa (EB) is a rare genetic disease characterised by skin fragility with blisters and erosions on the skin and/or mucous membranes. People with EB often experience several extracutaneous manifestations, including clinical and health-related quality of life (HRQoL) complications. Herein, we evaluate their HRQoL and clinical severity and propose an objective criterion for estimating nutritional compromise using the Birmingham Epidermolysis Bullosa Severity Score (BEBS) tool.

METHODS

this series of cases included people with EB, monitored by a multi-professional team. Clinical severity was assessed with the BEBS, using body mass index ranges by age, as an objective proposal, to estimate the degree of nutritional compromise. To assess HRQoL, the Children's Dermatology Life Quality Index (individuals aged 4-16 years) and the Quality of Life Evaluation in Epidermolysis Bullosa - Brazilian Portuguese (individuals 17 years and over) were used.

RESULTS

of the nine individuals with recessive dystrophic EB (88.9 % female and 12.91 (SD = 11.71) years), the mean total BEBS score was 24.47 (SD = 12.80) points on a scale of 0 to 100 points. Six participants had significant nutritional compromise according to the proposed criteria. Five of the six participants evaluated for HRQoL reported experiencing some impact, with individuals aged 17 and over being more affected and with greater clinical severity.

CONCLUSIONS

individuals with greater clinical severity of EB experience a more significant impact on their HRQoL. The proposed quantitative criteria for assessing nutritional compromise may help standardise assessments by professionals monitoring the nutritional status of individuals with EB.

Revolutionary breakthrough: FDA approves Vyjuvek, the first topical gene therapy for dystrophic epidermolysis bullosa

This article provides an updated overview of Vyjuvek, a Food and Drug Administration (FDA) approved medication and its potential in managing dystrophic epidermolysis bullosa (DEB). DEB is a rare genetic disorder characterized by skin fragility, blistering, wounds, and scarring. The underlying cause of DEB is the impaired production of type VII collagen (COL7), leading to weakened anchoring fibrils in the skin. Vyjuvek is the first topical gene therapy for DEB, utilizing a genetically modified HSV-1 (herpes simplex virus 1) vector to express human COL7 and promote wound healing. Clinical trials have shown that Vyjuvek increases the probability of complete wound healing compared to placebo. Although further research is needed, Vyjuvek represents a significant advancement in addressing the unmet medical needs of patients with DEB, offering hope for improved quality of life and long-term complication reduction.

Phenotype and genotype correlation of inherited epidermolysis bullosa in Indonesia

BACKGROUND

Inherited epidermolysis bullosa (EB) is a group of genodermatoses with considerable clinical and genetic heterogeneity. Clinical diagnosis of the EB subtypes is frequently imprecise and requires confirmation with genetic testing. There is still limited study using genetic testing to identify EB subtypes in Indonesia. This study aims to identify the pathogenic variants of inherited EB patients at the Department of Dermatology and Venereology, Universitas Padjadjaran-Dr Hasan Sadikin General Hospital in Bandung, West Java, Indonesia and to describe the correlation between the phenotype and genotype of our patients.

METHODS

Twelve patients clinically diagnosed with EB were included in this study. Genetic testing was performed in collaboration with KK Women's and Children's Hospital, Singapore.

RESULTS

Pathogenic variants were identified in the COL7A1 gene in seven patients, namely Dominant Dystrophic EB (DDEB) with mutation types c.5945G>T, c.6218G>A, Recessive Dystrophic EB (RDEB) c.2005C>T, c.6081dup, c.1268C>T, c.1784C>T which are all known mutations. Novel mutations were found in the COL7A1 gene in two patients namely DDEB c.6253G>T and RDEB c.6740C>T. Two EB Simplex (EBS) patients showed mutation KRT14 gene as c.356T>C, c.373C>T which are known mutation. In addition, a novel mutation in LAMA3 gene c.2649del was found in one Junctional EB (JEB) patient.

CONCLUSION

The molecular diagnoses of 12 Indonesian EB patients were identified, of which three were novel pathogenic variants. Concordance between the initial clinical diagnosis and genetic testing was only 33%. This demonstrated the importance of early genetic testing for accurate diagnosis, prognostication, management and genetic counselling.

Type VII Collagen Deficiency in the Oncogenesis of Cutaneous Squamous Cell Carcinoma in Dystrophic Epidermolysis Bullosa

Dystrophic epidermolysis bullosa is a rare genetic skin disorder caused by COL7A1 sequence variations that result in type VII collagen deficits and cutaneous and extracutaneous manifestations. One serious complication of dystrophic epidermolysis bullosa is cutaneous squamous cell carcinoma, a leading driver of morbidity and mortality, especially among patients with recessive dystrophic epidermolysis bullosa. Type VII collagen deficits alter TGFβ signaling and evoke multiple other cutaneous squamous cell carcinoma progression-promoting activities within epidermal microenvironments. This review examines cutaneous squamous cell carcinoma pathophysiology in dystrophic epidermolysis bullosa with a focus on known oncogenesis pathways at play and explores the idea that therapeutic type VII collagen replacement may reduce cutaneous squamous cell carcinoma risk.

Clinical and molecular features in a cohort of Middle Eastern patients with epidermolysis bullosa

BACKGROUND

Epidermolysis bullosa (EB) features skin and mucosal fragility due to pathogenic variants in genes encoding components of the cutaneous basement membrane. Based on the level of separation within the dermal-epidermal junction, EB is sub-classified into four major types including EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB), and Kindler EB (KEB) with 16 EB-associated genes reported to date.

METHODS

We ascertained a cohort of 151 EB patients of various Middle Eastern ethnic backgrounds.

RESULTS

The cohort was comprised of EBS (64%, 97/151), DEB (21%, 31/151), JEB (12%, 18/151), and KEB (3%, 5/151). KRT14 and KRT5 variants were most common among EBS patients with 43% (42/97) and 46% (45/97) of EBS patients carrying mutations in either of these two genes, respectively. Truncal involvement was more common in KRT14-associated EBS as compared to EBS due to KRT5 mutations (p < .05). Mutations in COL17A1 and laminin 332-encoding genes were identified in 55% (10/18) and 45% (8/18) of JEB patients. Scarring alopecia, caries, and EB nevi were most common among JEB patients carrying COL17A1 mutations as compared to laminin 332-associated JEB (p < .05). Abnormal nails were evident in most DEB and JEB patients while poikiloderma was exclusively observed in KEB (p < .001).

CONCLUSIONS

EB patients of Middle Eastern origin were found to feature specific phenotype-genotype correlations of relevance to the diagnosis and genetic counseling of patients in this region.

Next-generation sequencing in dermatology

Over the past decade, Next-Generation Sequencing (NGS) has advanced our understanding, diagnosis, and management of several areas within dermatology. NGS has emerged as a powerful tool for diagnosing genetic diseases of the skin, improving upon traditional PCR-based techniques limited by significant genetic heterogeneity associated with these disorders. Epidermolysis bullosa and ichthyosis are two of the most extensively studied genetic diseases of the skin, with a well-characterized spectrum of genetic changes occurring in these conditions. NGS has also played a critical role in expanding the mutational landscape of cutaneous squamous cell carcinoma, enhancing our understanding of its molecular pathogenesis. Similarly, genetic testing has greatly benefited melanoma diagnosis and treatment, primarily due to the high prevalence of BRAF hot spot mutations and other well-characterized genetic alterations. Additionally, NGS provides a valuable tool for measuring tumor mutational burden, which can aid in management of melanoma. Lastly, NGS demonstrates promise in improving the sensitivity of diagnosing cutaneous T-cell lymphoma. This article provides a comprehensive summary of NGS applications in the diagnosis and management of genodermatoses, cutaneous squamous cell carcinoma, melanoma, and cutaneous T-cell lymphoma, highlighting the impact of NGS on the field of dermatology.

Molecular-based phenotype variations in amelogenesis imperfecta

Amelogenesis imperfecta (AI) is one of the typical dental genetic diseases in human. It can occur isolatedly or as part of a syndrome. Previous reports have mainly clarified the types and mechanisms of nonsyndromic AI. This review aimed to compare the phenotypic differences among the hereditary enamel defects with or without syndromes and their underlying pathogenic genes. We searched the articles in PubMed with different strategies or keywords including but not limited to amelogenesis imperfecta, enamel defects, hypoplastic/hypomaturation/hypocalcified, syndrome, or specific syndrome name. The articles with detailed clinical information about the enamel and other phenotypes and clear genetic background were used for the analysis. We totally summarized and compared enamel phenotypes of 18 nonsyndromic AI with 17 causative genes and 19 syndromic AI with 26 causative genes. According to the clinical features, radiographic or ultrastructural changes in enamel, the enamel defects were basically divided into hypoplastic and hypomineralized (hypomaturated and hypocalcified) and presented a higher heterogeneity which were closely related to the involved pathogenic genes, types of mutation, hereditary pattern, X chromosome inactivation, incomplete penetrance, and other mechanisms.The gene-specific enamel phenotypes could be an important indicator for diagnosing nonsyndromic and syndromic AI.

Extracellular matrix in skin diseases: The road to new therapies

BACKGROUND

The extracellular matrix (ECM) is a vital structure with a dynamic and complex organization that plays an essential role in tissue homeostasis. In the skin, the ECM is arranged into two types of compartments: interstitial dermal matrix and basement membrane (BM). All evidence in the literature supports the notion that direct dysregulation of the composition, abundance or structure of one of these types of ECM, or indirect modifications in proteins that interact with them is linked to a wide range of human skin pathologies, including hereditary, autoimmune, and neoplastic diseases. Even though the ECM's key role in these pathologies has been widely documented, its potential as a therapeutic target has been overlooked.

AIM OF REVIEW

This review discusses the molecular mechanisms involved in three groups of skin ECM-related diseases - genetic, autoimmune, and neoplastic - and the recent therapeutic progress and opportunities targeting ECM.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This article describes the implications of alterations in ECM components and in BM-associated molecules that are determinant for guaranteeing its function in different skin disorders. Also, ongoing clinical trials on ECM-targeted therapies are discussed together with future opportunities that may open new avenues for treating ECM-associated skin diseases.

Autoimmunity against laminin 332

Laminin 332 is a heterotrimeric structural protein of the basal membrane zone (BMZ) of the skin and adjacent mucosal tissues. The importance of laminin 332 for the structural integrity of the BMZ is demonstrated by mutations in any of the three genes encoding for its three chains causing variants of junctional epidermolysis bullosa. Autoimmunity against laminin 332 is observed in mucous membrane pemphigoid (MMP) and in the rare patients with orf-induced pemphigoid. MMP is an autoimmune blistering disease with predominant mucosal manifestations and autoantibodies against the BMZ of the skin and orifice-close mucous membranes. The main autoantigens of MMP are type XVII collagen (BP180) and laminin 332 targeted in about 80% and 10-20% of patients, respectively. An increasing number of studies has highlighted the association of anti-laminin 332 MMP and malignancies that can be revealed in about a quarter of these patients. This data has led to the recommendation of current guidelines to assay for anti-laminin 332 reactivity in all MMP patients. The present review focuses on anti-laminin 332 MMP describing clinical features, its pathophysiology, and detection of serum anti-laminin 332 IgG. In addition, the available data about the occurrence of malignancies in anti-laminin 332 MMP, the underlying tumor entities, and its biology are detailed.

Clinical and allelic heterogeneity in dystrophic epidermolysis bullosa- lessons from an Indian cohort

BACKGROUND

Dystrophic epidermolysis bullosa (DEB) is due to variation in the COL7A1 gene. The clinical phenotype and severity depends on the type of variation and domain of the affected protein.

OBJECTIVES

To characterize the spectrum of COL7A1 variations in a cohort of DEB patients from India, to correlate these findings with clinical phenotypes and to establish a genotype-phenotype correlation.

METHODS

This was a retrospective, observational study involving patients with DEB diagnosed on the basis of clinical manifestations, Immuno-fluorescence antigen mapping (IFM) and genetic analysis. A genotype-phenotype correlation was attempted and observations were further explained using IFM on skin biopsies and molecular dynamic simulations. Descriptive statistics were performed using SPSS version 20.0 with P values of <0.05 considered significant.

RESULTS

We report 68 unrelated Indian DEB patients classified as RDEB-Intermediate (RDEB-I), RDEB-Severe (RDEB-S) or DDEB based on the EB diagnostic matrix, immunofluorescence antigen mapping and genetic data. Of 68 DEB patients, 59 (86.76%) were inherited in a recessive pattern (RDEB) and 9 (13.24%) in a dominant pattern (DDEB). Limbal stem cell deficiency was seen in four cases of RDEB-S very early in the course of the disease. A total of 88 variants were detected of which 66 were novel. There were no hotspots and recurrent variations were seen in a very small group of patients. We found a high frequency of compound heterozygotes (CH) in RDEB patients born out of non-consanguineous marriage. RDEB patients older than two years who had oral mucosal involvement, and/or deformities, were more likely to have esophageal involvement. Genotype phenotype correlation showed a higher frequency of extracutaneous manifestations and deformities in patients with Premature Termination Codons (PTCs) than in patients with other variations. Molecular simulation studies in patients with missense mutations showed severe phenotype when they were localized in interrupted regions of GLY-X-Y repeats.

CONCLUSION

This large study of DEB patients in South Asia adds to the continually expanding genetic database of this condition. This study has direct implications on management as this group of patients can be screened early and managed appropriately.

Epidermolysis Bullosa Simplex With Dystonin Gene Mutation: First Reported Case in Saudi Arabia

We report a case of a 3-year-old Saudi female patient as the first case reported in Saudi Arabia who is homozygous for dystonin c.3370C>T, p.(Gln1124*). At the age of 3 months, the girl started to develop numerous vesicles and bullae involving the dorsum of the feet that were not on a pressure site, with remission and aggravation, but she had no mucosal lesions or nail affection. The patient was diagnosed with epidermolysis bullosa simplex.

Conservative Management of a Rare Entity-Aplasia Cutis Congenita: A Case Report

Aplasia cutis congenita (ACC) is a rare entity characterized by a congenital localized absence of the skin, dermal appendages, and subcutaneous tissue. The cause of ACC is not clear, but inheritance is the most widely accepted cause. We report a rare case of a full-term (37 + 5 weeks) female newborn who showed complete absence of skin in localized areas of the upper and lower extremities. The patient was diagnosed with ACC associated with epidermolysis bullosa (EB; a disease that causes the skin to blister easily) and was initially treated using conservative measures. We applied mupirocin topical ointment and a nonocclusive polyester mesh impregnated with hydrocolloid and petroleum jelly daily. Complete healing of the affected areas occurred after 3 weeks. Managing patients with ACC is often challenging and based on the severity of the lesions, the approach may include both surgical and conservative treatment. Our case report suggests that a conservative approach can be effective for managing certain types of ACC and EB lesions. However, further research is warranted to better understand the pathogenesis and optimal management of this entity.

Maintenance of chronicity signatures in fibroblasts isolated from recessive dystrophic epidermolysis bullosa chronic wound dressings under culture conditions

BACKGROUND

Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a rare inherited skin disease caused by variants in the COL7A1 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.

RESULTS

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.

CONCLUSIONS

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.

Assessment of nutrient intakes of children and adolescents with recessive dystrophic epidermolysis bllosa, severe subtype

Introduction

Background and aims: epidermolysis bullosa (EB) is a rare disease presenting with skin fragility and formation of blisters. Constant presence of skin lesions, loss of blood, wastage of heat through the open skin, increased turnover of proteins and infections, result in increased energy, protein, and micronutrient needs. This study investigated the intake adequacy of energy, protein, zinc, iron, and dietary fiber in children with epidermolysis bullosa. Methods: this cross-sectional, analytical study was conducted with children and adolescents of up to 18 years of age with recessive dystrophic EB, severe subtype. Demographic data and clinical manifestations affecting food consumption were collected. Nutritional assessment was performed through anthropometric data. We used a formula to estimate specific energy needs for EB, and ratio of skin lesions was also evaluated to assist in estimating energy needs. A protein adequacy of 115 % to 200 % of the Recommended Dietary Allowance was considered for the adequacy of protein intake. And the Dietary Reference Intake tables according to sex and age were used as a reference for micronutrients. Intake assessment was performed using seven consecutive daily food records. Sip feed consumption was considered for intake assessment. Results: all patients showed undernutrition and presented at least three clinical symptoms that affect food consumption: pseudosyndactyly, microstomy, and blisters in the oral cavity. Sip feed constituted between 20 % and 50 % of the patients' energy intake. Intake of iron and zinc was adequate for most patients (confidence of adequacy ≥ 0.85), while fiber intake was below the reference value. Conclusions: this study underscores the importance of nutritional monitoring for EB patients, which is often interpreted as a skin disease but has enormous nutritional repercussions.

Our experience of using Losartan for esophageal stenosis in children with dystrophic form of congenital epidermolysis bullosa

INTRODUCTION

Dystrophic epidermolysis bullosa (DEB) is one of the most severe forms of congenital epidermolysis bullosa and characterized by the formation of many surgical complications. Esophageal stenosis is a common complication of DEB and occurs in almost 76% of cases. Balloon dilatation (BD) under X-ray control is the main therapeutic technique, however conservative treatment is necessary to prevent restenosis. The use of the drug losartan is promising due to its antifibrotic effect through the suppression of transforming growth factor-β1 (TGF-β1).

PURPOSE

To evaluate the efficacy of losartan in the prevention of restenosis after BD of esophageal stenosis in children with DEB.

MATERIALS AND METHODS

The study included 19 children from 2 to 16 years old (mean age 9.2 ± 3.58 years) with DEB and X-ray confirmed esophageal stenosis. All children underwent BD. In the main group 9 children after BD have received losartan, in the control group of 10 children - only standard therapy. The observation period was 12 months.

RESULTS

In the main group, 1 child (11.1%) required repeated dilatation, in the control group - 4 children (40%). Indicators of nutritional deficiency (THINC scale) and the disease severity index (EBDASI) were significantly lower in the group of children treated with losartan. No undesirable actions of the drug were recorded.

CONCLUSIONS

In this study losartan showed its safety, contributed to a decrease in the restenosis frequency and an improvement in the nutritional status of children with DEB after BD. However, further studies are required to confirm its effectiveness.

LEVEL OF EVIDENCE

IV.

Stem Cell Therapies for Epidermolysis Bullosa Treatment

Epidermolysis bullosa (EB) includes a group of rare skin diseases characterized by skin fragility with bullous formation in the skin, in response to minor mechanical injury, as well as varying degrees of involvement of the mucous membranes of the internal organs. EB is classified into simplex, junctional, dystrophic and mixed. The impact of the disease on patients is both physical and psychological, with the result that their quality of life is constantly affected. Unfortunately, there are still no approved treatments available to confront the disease, and treatment focuses on improving the symptoms with topical treatments to avoid complications and other infections. Stem cells are undifferentiated cells capable of producing, maintaining and replacing terminally differentiated cells and tissues. Stem cells can be isolated from embryonic or adult tissues, including skin, but are also produced by genetic reprogramming of differentiated cells. Preclinical and clinical research has recently greatly improved stem cell therapy, making it a promising treatment option for various diseases in which current medical treatments fail to cure, prevent progression, or alleviate symptoms. So far, stem cells from different sources, mainly hematopoietic and mesenchymal, autologous or heterologous have been used for the treatment of the most severe forms of the disease each one of them with some beneficial effects. However, the mechanisms through which stem cells exert their beneficial role are still unknown or incompletely understood and most importantly further research is required to evaluate the effectiveness and safety of these treatments. The transplantation of skin grafts to patients produced by gene-corrected autologous epidermal stem cells has been proved to be rather successful for the treatment of skin lesions in the long term in a limited number of patients. Nevertheless, these treatments do not address the internal epithelia-related complications manifested in patients with more severe forms.

Case report: A case of epidermolysis bullosa complicated with pyloric atresia and a literature review

Objective

This article aims to explore the diagnosis, molecular characteristics, treatment, and prognosis of epidermolysis bullosa with pyloric atresia (EB-PA).

Methods

The clinical manifestations, diagnosis and treatment, and genetic characteristics of a patient with EB-PA admitted to our hospital were analysed. The disease subtypes, concomitant abnormalities, molecular characteristics, and prognosis of patients with EB-PA were summarized by searching the EB-PA-related literature since 2011.

Results

We present a very low birth weight female infant with skin blisters and pyloric obstruction. Exome sequencing revealed heterozygous mutations in the ITGB4 gene: c.794dupC (p. S265fs*5) and c.2962G > A (p.A988T). This infant was diagnosed with EB-PA. Coverage of the wounds and Penicillin were used to prevent infection, but the patient eventually developed severe sepsis. A literature review was carried out including 49 cases of EB-PA; among these cases, 34 were preterm infants, weighing between 930 and 3,640 g. Of these EB-PA patients, 28 had accompanying malformations, including urinary system malformations and aplasia cutis congenita (ACC). Thirty-two patients identified the subtype of EB-PA, of whom 25 were diagnosed with junctional epidermolysis bullosa (JEB), 6 with epidermolysis bullosa simplex (EBS), and 1 with dystrophic epidermolysis bullosa (DEB). Genetic testing was conducted on 23 patients, of whom 15 carried Integrin Beta-4 (ITGB4) gene mutations and one JEB patient carried an Integrin Alpha-6 (ITGA6) gene mutation; 4 of the 5 EBS patients had Plectin (PLEC) gene mutations, and the other had an ITGB4 mutation. ITGB4 mutation cases involved 29 mutation sites, primarily concentrated in the region encoding the integrin beta subunit; PLEC mutation cases involved 7 mutation sites. Among all cases, 43 underwent pyloric atresia surgery, of whom 24 died postoperatively, and 6 without surgery therapy died within a short period.

Conclusion

EB-PA is a rare genetic disorder characterized by increased skin fragility and PA involving mutations in the ITGB4, PLEC, or ITGA6 genes. EB-PA has a high incidence of complications and mortality, surgery and supportive therapy are currently the most common treatment options.

Multifaceted functions of RPS27a: An unconventional ribosomal protein

The ribosomal protein S27a (RPS27a) is cleaved from the fusion protein ubiquitin-RPS27a (Ub-RPS27a). Generally, Ub and RPS27a are coexpressed as a fusion protein but function independently after Ub is cleaved from RPS27a by a deubiquitinating enzyme. As an RP, RPS27a assembles into ribosomes, but it also functions independently of ribosomes. RPS27a is involved in the development and poor prognosis of various cancers, such as colorectal cancer, liver cancer, chronic myeloid leukemia, and renal carcinoma, and is associated with poor prognosis. Notably, the murine double minute 2/P53 axis is a major pathway through which RPS27a regulates cancer development. Moreover, RPS27a maintains sperm motility, regulates winged aphid indirect flight muscle degeneration, and facilitates plant growth. Additionally, RPS27a is a metalloprotein and mercury (Hg) biomarker. In the present review, we described the origin, structure, and biological functions of RPS27a.

Rare diseases of ectoderm: Translating discovery to therapy

Heritable conditions known as ectodermal dysplasias are rare and can be associated with marked morbidity, mortality, and a reduced quality of life. The diagnosis and care of individuals affected by one of the many ectodermal dysplasias presents myriad challenges due to their rarity and the diverse phenotypes. These conditions are caused by abnormalities in multiple genes and signaling pathways that are essential for the development and function of ectodermal derivatives. During a 2021 international conference focused on translating discovery to therapy, researchers and clinicians gathered with the goal of advancing the diagnosis and treatment of conditions affecting ectodermal tissues with an emphasis on skin, hair, tooth, and eye phenotypes. Conference participants presented a variety of promising treatment strategies including gene or protein replacement, gene editing, cell therapy, and the identification of druggable targets. Further, barriers that negatively influence the current development of novel therapeutics were identified. These barriers include a lack of accurate prevalence data for rare conditions, absence of an inclusive patient registry with deep phenotyping data, and insufficient animal models and cell lines. Overcoming these barriers will need to be prioritized in order to facilitate the development of novel treatments for genetic disorders of the ectoderm.

COL7A1 Editing via RNA Trans-Splicing in RDEB-Derived Skin Equivalents

Mutations in the COL7A1 gene lead to malfunction, reduction or complete absence of type VII collagen (C7) in the skin's basement membrane zone (BMZ), impairing skin integrity. In epidermolysis bullosa (EB), more than 800 mutations in COL7A1 have been reported, leading to the dystrophic form of EB (DEB), a severe and rare skin blistering disease associated with a high risk of developing an aggressive form of squamous cell carcinoma. Here, we leveraged a previously described 3'-RTMS6m repair molecule to develop a non-viral, non-invasive and efficient RNA therapy to correct mutations within COL7A1 via spliceosome-mediated RNA trans-splicing (SMaRT). RTM-S6m, cloned into a non-viral minicircle-GFP vector, is capable of correcting all mutations occurring between exon 65 and exon 118 of COL7A1 via SMaRT. Transfection of the RTM into recessive dystrophic EB (RDEB) keratinocytes resulted in a trans-splicing efficiency of ~1.5% in keratinocytes and ~0.6% in fibroblasts, as confirmed on mRNA level via next-generation sequencing (NGS). Full-length C7 protein expression was primarily confirmed in vitro via immunofluorescence (IF) staining and Western blot analysis of transfected cells. Additionally, we complexed 3'-RTMS6m with a DDC642 liposomal carrier to deliver the RTM topically onto RDEB skin equivalents and were subsequently able to detect an accumulation of restored C7 within the basement membrane zone (BMZ). In summary, we transiently corrected COL7A1 mutations in vitro in RDEB keratinocytes and skin equivalents derived from RDEB keratinocytes and fibroblasts using a non-viral 3'-RTMS6m repair molecule.

Pruriginosa Pattern of Dystrophic Epidermolisys Bullosa: Clinical Case

Background. Epidermolisys bullosa pruriginosa is a rare pattern of dystrophic epidermolisys bullosa and characterized by severe itching that accompanies the formation of papules, plaques and nodes primarily on the lower limbs skin and imitating prurigo nodularis. Nowadays, less than 100 cases of this disease are reported in the world, thus, the presentation of this clinical case is relevant. Clinical case description. The authors describe the clinical case of pruriginous pattern of dominant dystrophic bullous epidermolysis in 14-year-old female patient. Conclusion. Diagnosis of this disease pattern is extremely difficult and currently all treatment is limited to the symptomatic therapy in order to stop itching and prevent scarring.

Recessive dystrophic epidermolysis bullosa (RDEB): Oral manifestation and management rules in oral surgery: A case report

INTRODUCTION AND IMPORTANCE

The recessive dystrophic epidermolysis bullosa is a severe form of hereditary epidermolysis bullosa characterized by deformities of the skin, blisters and erosions on the mucous membranes. Oral manifestations are frequent and extensive vary from small discrete vesicles to large bullae, associated with microstomia, ankyloglossia and a depapilled tongue. The purpose of this case report is to describe oral health status of patient with recessive-dystrophic epidermolysis bullosa, and the measures that dentists should adopt with the purpose of provide an effective dental treatment.

CASE PRESENTATION

We present a clinical case of a patient with recessive-dystrophic epidermolysis bullosa who underwent a bone regularization and whose follow-up was carried out until healing.

CLINICAL DISCUSSION

The management of patients with RDEB in oral surgery requires the adoption of an atraumatic technique and certain precautions to limit the formation of bullae and promote mucosal healing.

CONCLUSION

We can conclude that oral management of patients with recessive dystrophic epidermolysis bullosa presents a challenge for the oral surgeon and the management is generally multidisciplinary and relies essentially on the adoption of a preventive and atraumatic approach.

Junctional epithelium and hemidesmosomes: Tape and rivets for solving the "percutaneous device dilemma" in dental and other permanent implants

The percutaneous device dilemma describes etiological factors, centered around the disrupted epithelial tissue surrounding non-remodelable devices, that contribute to rampant percutaneous device infection. Natural percutaneous organs, in particular their extracellular matrix mediating the "device"/epithelium interface, serve as exquisite examples to inspire longer lasting long-term percutaneous device design. For example, the tooth's imperviousness to infection is mediated by the epithelium directly surrounding it, the junctional epithelium (JE). The hallmark feature of JE is formation of hemidesmosomes, cell/matrix adhesive structures that attach surrounding oral gingiva to the tooth's enamel through a basement membrane. Here, the authors survey the multifaceted functions of the JE, emphasizing the role of the matrix, with a particular focus on hemidesmosomes and their five main components. The authors highlight the known (and unknown) effects dental implant - as a model percutaneous device - placement has on JE regeneration and synthesize this information for application to other percutaneous devices. The authors conclude with a summary of bioengineering strategies aimed at solving the percutaneous device dilemma and invigorating greater collaboration between clinicians, bioengineers, and matrix biologists.

Mutation update: The spectra of PLEC sequence variants and related plectinopathies

Plectin, encoded by PLEC, is a cytoskeletal linker of intermediate filaments expressed in many cell types. Plectin consists of three main domains that determine its functionality: the N-terminal domain, the Rod domain, and the C-terminal domain. Molecular defects of PLEC correlating with the functional aspects lead to a group of rare heritable disorders, plectinopathies. These multisystem disorders include an autosomal dominant form of epidermolysis bullosa simplex (EBS-Ogna), limb-girdle muscular dystrophy (LGMD), aplasia cutis congenita (ACC), and an autosomal recessive form of EBS, which may associate with muscular dystrophy (EBS-MD), pyloric atresia (EBS-PA), and/or congenital myasthenic syndrome (EBS-MyS). In this study, genotyping of over 600 Iranian patients with epidermolysis bullosa by next-generation sequencing identified 15 patients with disease-causing PLEC variants. This mutation update analyzes the clinical spectrum of PLEC in our cohort and in the literature and demonstrates the relationship between PLEC genotype and phenotypic manifestations. This study has integrated our seven novel PLEC variants and phenotypic findings with previously published data totaling 116 variants to provide the most complete overview of pathogenic PLEC variants and related disorders.

The basement membrane in epidermal polarity, stemness, and regeneration

The epidermis is a specialized epithelium that constitutes the outermost layer of the skin, and it provides a protective barrier against environmental assaults. Primarily consisting of multilayered keratinocytes, the epidermis is continuously renewed by proliferation of stem cells and the differentiation of their progeny, which undergo terminal differentiation as they leave the basal layer and move upward toward the surface, where they die and slough off. Basal keratinocytes rest on a basement membrane at the dermal-epidermal junction that is composed of specific extracellular matrix proteins organized into interactive and mechanically supportive networks. Firm attachment of basal keratinocytes, and their dynamic regulation via focal adhesions and hemidesmosomes, is essential for maintaining major skin processes, such as self-renewal, barrier function, and resistance to physical and chemical stresses. The adhesive integrin receptors expressed by epidermal cells serve structural, signaling, and mechanosensory roles that are critical for epidermal cell anchorage and tissue homeostasis. More specifically, the basement membrane components play key roles in preserving the stem cell pool, and establishing cell polarity cues enabling asymmetric cell divisions, which result in the transition from a proliferative basal cell layer to suprabasal cells committed to terminal differentiation. Finally, through a well-regulated sequence of synthesis and remodeling, the components of the dermal-epidermal junction play an essential role in regeneration of the epidermis during skin healing. Here too, they provide biological and mechanical signals that are essential to the restoration of barrier function.

Potential di-genic contribution to guttate leukoderma as the predominant feature of epidermolysis bullosa simplex

Inherited epidermolysis bullosa (EB) simplex is a heterogeneous group of skin fragility disorders caused by mutations in genes encoding cell-cell or cell-matrix adhesion proteins. A recently identified, rare subtype of EB simplex is due to bi-allelic mutations in the EXPH5 gene, which encodes exophilin5, an effector protein of the Rab27B GTPase involved in intracellular vesicle trafficking and exosome secretion. The EXPH5 EB subtype is characterized by early-onset skin blisters and scars, mainly on extremities, and varying degrees of pigmentary alterations. Here, we present a 31-year-old female with diffuse guttate hypopigmentation on the trunk and extremities since early childhood, with no apparent blisters or scars. We employed whole exome sequencing of germline DNA extracted from the patient's leukocytes to determine the genetic aetiology of the phenotype. A novel homozygous variant in EXPH5, c.1153C>T causing a premature stop codon at amino acid Glutamine 385, was identified. Histologic examination after skin pricking disclosed focal keratinocyte detachment typical to EB. Additionally, we identified a deleterious-predicted variant in ENPP1, a gene associated with disturbed transfer of melanosomes to keratinocytes in Cole disease. Our report expands the clinical spectrum of inherited EB simplex with a possible di-genic synergism contributing to co-presentation with guttate leukoderma.

Junctional epidermolysis bullosa: genotype-phenotype correlations

Junctional epidermolysis bullosa most commonly results from mutations in theLAMA3, LAMB3, LAMC2, COL17A1, ITGA6 and ITGB4genes. Junctional epidermolysis bullosa is characterized by clinical heterogeneity. To date, scientific findings allow to evaluate correlations between the severity of clinical manifestations and genetic defects underlying in the development of the disease. A systematic literature search was performed using PubMed and RSCI, and keywords including junctional epidermolysis bullosa, laminin 332, collagen XVII, 64 integrin. The review includes description of clinical findings of junctional epidermolysis bullosa, mutation location and types, its impact on protein production and functions. To evaluate the impact of gene mutation on protein functions, this review explores the structure and functions of lamina lucida components, including laminin 332, collagen XVII and 64 integrin, which are frequently associated with the development of junctional epidermolysis bullosa. The correlation between severe types of junctional epidermolysis bullosa and mutations resulting in premature stop codon generation and complete absence of protein expression has been described. Although, genotype-phenotype correlations should be analyzed carefully due to mechanisms which enable to improve protein expression.

Targeted NGS in Diagnostics of Genodermatosis Characterized by the Epidermolysis Bullosa Symptom Complex in 268 Russian Children

The pathogenic variants of genes encoding proteins, participating in the formation and functioning of epidermis and dermo-epidermal junctions, create a large variety of clinical phenotypes from: small localized to severe generalized dermatitis, as well as early, or even, prenatal death due to extensive epidermis loss. The diagnostic panel in this study was developed for the purposes of identifying these pathogenic genetic variants in 268 Russian children, who possessed the epidermolysis bullosa symptom complex in a selection of 247 families. This panel included the targeted areas of 33 genes, which are genetic variants that can lead to the development of the phenotype mentioned above. The usage of next generation sequencing allowed the revelation of 192 various altered alleles (of which 109 alleles were novel, i.e., had not been described previously). In addition, it allowed the definition of the genetic variants that are both typical for most of the examined children and for the separate ethnic groups inhabiting modern Russia. We found that the most characteristic mutations for the Dargin and Chechen ethnic groups are the c.3577del deletion in the COL7A1 gene and the c.2488G>A missense mutation in the COL17A1 gene, respectively. In addition, the study of haplotypes of microsatellite markers, which we managed to conduct in the Dargin population, confirmed the presence of the founder effect.

Long Hanging Structure of Collagen VII Connects the Elastic Fibers and the Basement Membrane in Young Skin Tissue

Aging leads to substantial structural changes in the skin. Elastic fibers maintain skin structure, but their degeneration and loss of function with age result in wrinkle formation and loss of skin elasticity. Oxytalan fiber, a type of elastic fiber, extends close to the dermal-epidermal junction (DEJ) from the back of the dermis. Oxytalan fibers are abundant in the papillary layer and contribute to skin elasticity and texture. However, to accurately understand the mechanisms of skin elasticity, the interaction between elastic fibers and DEJ should be elucidated. Here, we investigated elastic fibers and DEJ and their structural alterations with aging. Several basement membrane proteins [collagen (COL) IV, COLVII, and laminin 332], fibrous tropoelastin, and fibrillin-1 in excised human skin tissue were observed using three-dimensional imaging. Age-related alterations in COLVII, elastic fibers, and fibrillin-1 were evaluated. We found that COLVII forms long hanging structures and is co-localized with fibrous tropoelastin in young skin but not aged skin. Fibrillin-1-rich regions were observed at the tips of elastin fibers in young skin tissue, but rarely in aged skin. This co-localization of elastic fiber and COLVII may maintain skin structure, thereby preventing wrinkling and sagging. COLVII is a potential therapeutic target for skin wrinkling.

Rare compound heterozygous variants of LAMB3 and histological features of enamel and oral mucosa

Junctional epidermolysis bullosa (JEB) is a group of autosomal recessive disorders characterized by amelogenesis imperfecta (AI) and fragility of the skin and mucous membranes. The purpose of this study was to identify pathogenic gene variants and investigate the phenotypic characteristics of abnormal enamel structure and mucocutaneous lesions in a patient with JEB. Clinical examination of the patient revealed hypoplastic AI, skin lesions, and oral ulcers, whereas her parents were normal. Whole-exome sequencing (WES) and cDNA cloning identified compound heterozygous variants of LAMB3 in the proband: c.125G>C in exon 3, c.1288 + 1G>A in intron 11, and c.1348C>T in exon 12. Among these, c.125G>C was inherited from her father, and the other two variants were inherited from her mother. Functional prediction indicated that the variants might change protein structure and cause disease. Scanning electron microscopy (SEM) examination of the primary and permanent teeth revealed abnormal enamel morphology and microstructures. Hematoxylin-eosin (HE) and immunofluorescence (IF) staining showed significantly abnormal and disorganized epithelial cells in the gingival mucosa. Our results showed that this was a case of intermediate JEB1A (OMIM #226650) with autosomal recessive inheritance. The proband carried rare compound heterozygous variants of LAMB3. Our results broaden the variant spectrum of the LAMB3 gene and JEB cases. Moreover, this is the first study to identify histological malformations of the primary teeth and oral mucosa in LAMB3-related patients.

Efficacy Of Intradermal Allogeneic Fibroblast Injections In Junctional Epidermolysis Bullosa

Objective — to assess the efficacy and safety of intradermal injections of allogeneic fibroblasts into non-healing wounds in a patient with junctional epidermolysis bullosa. Material and Methods — A 49-year-old patient with intermediate junctional epidermolysis bullosa was injected intradermally into the base of non-healing wounds with 1 mL suspension of allogeneic fibroblasts, which contained 5×106 cells/mL, 10×106 cells/mL, and 20×106 cells/mL. Immunofluorescence mapping exhibited reduced β3 chain of laminin 332 and collagen XVII expression in the basement membrane area. Paired erosions were injected with 2% albumin or saline solution. Results — At two weeks after treatment, wound areas reduced significantly, or 100% re-epithelialization occurred. Collagen XVII and β3 chain expression of laminin 332 increased at the dermal-epidermal junction. Conclusion — Our findings demonstrated that intradermal injections of allogeneic fibroblasts could be an effective therapeutic approach for treating small non-healing wounds in junctional epidermolysis bullosa.

Towards a Better Understanding of Genotype-Phenotype Correlations and Therapeutic Targets for Cardiocutaneous Genes: The Importance of Functional Studies above Prediction

Genetic variants in gene-encoding proteins involved in cell−cell connecting structures, such as desmosomes and gap junctions, may cause a skin and/or cardiac phenotype, of which the combination is called cardiocutaneous syndrome. The cardiac phenotype is characterized by cardiomyopathy and/or arrhythmias, while the skin particularly displays phenotypes such as keratoderma, hair abnormalities and skin fragility. The reported variants associated with cardiocutaneous syndrome, in genes DSP, JUP, DSC2, KLHL24, GJA1, are classified by interpretation guidelines from the American College of Medical Genetics and Genomics. The genotype−phenotype correlation, however, remains poorly understood. By providing an overview of variants that are assessed for a functional protein pathology, we show that this number (n = 115) is low compared to the number of variants that are assessed by in silico algorithms (>5000). As expected, there is a mismatch between the prediction of variant pathogenicity and the prediction of the functional effect compared to the real functional evidence. Aiding to improve genotype−phenotype correlations, we separate variants into ‘protein reducing’ or ‘altered protein’ variants and provide general conclusions about the skin and heart phenotype involved. We conclude by stipulating that adequate prognoses can only be given, and targeted therapies can only be designed, upon full knowledge of the protein pathology through functional investigation.

Eye Involvement and Management in Inherited Epidermolysis Bullosa

Inherited epidermolysis bullosa (EB) is a group of genetic rare diseases associated with skin fragility, which leads to the formation of blisters, erosions, and scars on the skin and mucous membranes. Epidermolysis bullosa includes four main types and some several clinical subtypes including EB simplex, junctional EB, dystrophic EB, and Kindler's EB. Ocular involvement ranged from 51 to 68% in EB and can cause irreversible damages if not properly managed. Corneal erosions are the most common finding among series, including our cohort. We review here clinical and pathological features of ocular involvement in EB and the main keys for management, with a focus on recent innovative therapies.