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Objective: Epidermolysis bullosa (EB) is a rare genetic mucocutaneous disorder characterized by epithelial fragility leading to blister formation on skin and mucous membranes with even minor mechanical trauma. Most EB oral health publications give fragmented information, focusing on only one oral health aspect or one EB type. The aim of this study was to expand the knowledge of the overall oral health status of individuals with dystrophic, junctional, and simplex EB. Method and materials: A comparative multicenter study, including a control group, and based on questionnaires and clinical examinations, was undertaken in three EB expert centers. Results: Most EB (90.2%) participants brushed their teeth at least once a day despite the pain. The prevalence of enamel defects and caries experience did not differ between the 42 EB participants and the 42 age-/sex-matched healthy controls. Gingival inflammation unrelated to dental plaque accumulation was found in EB participants. Blisters, erythema, and erosion/ulceration mainly involved gingiva, buccal mucosa, lips, and palate, with different topographic patterns according to EB type. EB patients whatever the age showed a similar lesion distribution. Simplex and dystrophic EB patients under 12 years old displayed higher lesion severity than junctional EB ones. Only dystrophic type exhibited microstomia and ankyloglossia. Conclusion: Oral health status seemed to benefit from a close collaboration between dental practitioner and dermatologist, and from regular dental examination, starting at a young age and with a focus on prevention. The new appreciation of oral health involvement highlighted by this study is essential for EB patients care, regarding comorbidities and quality of life. [ABSTRACT FROM AUTHOR]

Epidermolysis bullosa (EB) is a heterogeneous group of genetic disorders characterized by the formation of blisters either spontaneously or at the sites of trauma. These heal with post-inflammatory hypopigmentation, scarring, or milia formation. We hereby present a child who presented with widespread hypopigmented atrophic areas, blistering at trauma-prone sites, and nail dystrophy. The significance of this particular case lies in the challenge of distinguishing between epidermolysis bullosa and bullous extragenital lichen sclerosus et atrophicus.

Abstract Background Inherited epidermolysis bullosa (EB) is a clinically and genetically heterogeneous group of skin fragility disorders characterized by blister formation following minor trauma. Four major types are distinguished based on the level of cleavage within the skin. Most EB forms present severely disabling cutaneous and systemic signs and symptoms. Management relies on daily time-consuming and distressing topical medications, and symptomatic treatment of systemic findings. Disease manifestations, symptoms, and daily care strongly affect patient and caregiver quality of life (QoL). To date, there are two validated EB-specific questionnaires, the “Quality of Life in Epidermolysis Bullosa” (QOLEB) and the “Epidermolysis Bullosa Burden of Disease” (EB-BoD) for the evaluation of patient and family disease burden, respectively. The aim of our study was to develop an Italian translation of the two questionnaires and to pilot-test them. Methods The guidelines for translation and cross-cultural adaptation of health-related QoL measures were followed. Initially, two separate translations were generated for each questionnaire, and subsequently reconciled by an expert committee. This was followed by a back-translation process. The original texts and all translations underwent revision by the expert committee, resulting in definitive versions. The final versions were then tested in a pilot study involving cognitive debriefing in a group of 17 families, representative of all EB major types. Results The translation and reconciliation process led to minor changes to obtain semantic/idiomatic/cultural equivalence of the Italian versions with the original ones and to reconcile the questions with the answer options. The cognitive debriefing process showed a good understanding and did not require text modifications. Conclusions The Italian versions of the QOLEB and EB-BoD provide valuable tools in everyday clinical practice of reference centers, and they allow the participation in multicenter international real-life observational studies as well as in controlled clinical trials. They enable the identification of disease-specific psychological and socioeconomic challenges for EB patients and their families, guiding targeted interventions to ensure appropriate and timely care.

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. [ABSTRACT FROM AUTHOR]

Abstract Background Junctional epidermolysis bullosa is a rare skin and mucosal disorder characterized by blister formation in response to minor trauma and extracutaneous manifestations. There have been no reports of cardiac surgery and prognostication in patients with epidermolysis bullosa due to skin and mucosal fragility. Case presentation A 55-year-old man presented with congenital junctional epidermolysis bullosa, hypertension, and vasospastic angina. He complained of dyspnea on exertion, and transthoracic echocardiography revealed severe aortic valve regurgitation, moderate aortic valve stenosis (tricuspid valve), and severe mitral valve regurgitation. Considering that the skin condition in the right chest wall was relatively healthy, the right thoracotomy approach was preferred and totally endoscopic concomitant mitral valve repair and aortic valve replacement were performed using a sutureless bioprosthetic valve (Perceval™ (Corcym, Group, Milan, Italy)). Polyurethane and silicon dressing foams were used to protect the skin at the site of contact with the bag valve mask, arterial pressure catheter, intravenous catheter, and the tracheal intubation tube. Vertical mattress sutures were used for the skin sutures. The postoperative course was uneventful, and the patient was discharged nine days after the operation. There was no indication for reoperation until three years follow-up period. Conclusions The totally endoscopic concomitant aortic and mitral valve surgery using Perceval™ prosthesis can be performed safely in patients with junctional epidermolysis bullosa by adequate protection of the skin and mucosa.

Background: Junctional epidermolysis bullosa is a rare skin and mucosal disorder characterized by blister formation in response to minor trauma and extracutaneous manifestations. There have been no reports of cardiac surgery and prognostication in patients with epidermolysis bullosa due to skin and mucosal fragility. Case presentation: A 55-year-old man presented with congenital junctional epidermolysis bullosa, hypertension, and vasospastic angina. He complained of dyspnea on exertion, and transthoracic echocardiography revealed severe aortic valve regurgitation, moderate aortic valve stenosis (tricuspid valve), and severe mitral valve regurgitation. Considering that the skin condition in the right chest wall was relatively healthy, the right thoracotomy approach was preferred and totally endoscopic concomitant mitral valve repair and aortic valve replacement were performed using a sutureless bioprosthetic valve (Perceval™ (Corcym, Group, Milan, Italy)). Polyurethane and silicon dressing foams were used to protect the skin at the site of contact with the bag valve mask, arterial pressure catheter, intravenous catheter, and the tracheal intubation tube. Vertical mattress sutures were used for the skin sutures. The postoperative course was uneventful, and the patient was discharged nine days after the operation. There was no indication for reoperation until three years follow-up period. Conclusions: The totally endoscopic concomitant aortic and mitral valve surgery using Perceval™ prosthesis can be performed safely in patients with junctional epidermolysis bullosa by adequate protection of the skin and mucosa. [ABSTRACT FROM AUTHOR]

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 (n = 5; 33%), followed by BP230 (n = 4; 27%), Type VII collagen (n = 4; 27%) and laminin‐332 (n = 1; 7%). The pathogenicity of these autoantibodies remains a subject for future experiments. [ABSTRACT FROM AUTHOR]

Epidermolysis bullosa is a group of inherited skin fragility disorders with blister formation in the basement membrane zone. Chronic scarring after repeated blistering of the hands causes narrowing of the first web, flexion contractures of the digits, and pseudosyndactyly. Junctional epidermolysis bullosa is a type of epidermolysis bullosa that is characterized by blister formation in the lamina lucida. This condition is associated with survival into adulthood. In adult survivors, hand function might be required in order to participate in normal social activities. However, there is a lack of literature on the management of hand surgery for adult patients with junctional epidermolysis bullosa. We herein describe an adult patient with junctional epidermolysis bullosa who had pseudosyndactyly and flexion contractures in both hands. Five surgeries were performed. Contractures were released and reconstructed using split- or full-thickness skin grafts. Delayed wound healing was always observed due to epidermal necrosis in the graft. After epithelialization, a satisfactory functional outcome was obtained.

Objective: Amelogenesis imperfecta (AI) is defined as inherited enamel malformations. LAMA3 (laminin alpha‐3) encodes a critical protein component of the basement membrane (laminin‐332). Individuals carrying heterozygous LAMA3 mutations have previously been shown to have localized enamel defects. This study aimed to define clinical phenotypes and to discern the genetic etiology for four AI kindreds. Materials and Methods: Whole‐exome analyses were conducted to search for sequence variants associated with the disorder, and micro‐computed tomography (μCT) to characterize the enamel defects. Results: The predominant enamel phenotype was generalized thin enamel with defective pits and grooves. Horizonal bands of hypoplastic enamel with chalky‐white discoloration and enamel hypomineralization were also observed and demonstrated by μCT analyses of affected teeth. Four disease‐causing LAMA3 mutations (NM_198129.4:c.3712dup; c.5891dup; c.7367del; c.9400G > C) were identified. Compound heterozygous MMP20 mutations (NM_004771.4:c.539A > G; c.692C > T) were also found in one proband with more severe enamel defects, suggesting a mutational synergism on disease phenotypes. Further analyses of the AI‐causing mutations suggested that both α3A (short) and α3B (long) isoforms of LAMA3 are essential for enamel formation. Conclusions: Heterozygous LAMA3 mutations can cause generalized enamel defects (AI1A) with variable expressivity. Laminin‐332 is critical not only for appositional growth but also enamel maturation. [ABSTRACT FROM AUTHOR]

Junctional epidermolysis bullosa most commonly results from mutations in the LAMA3, LAMB3, LAMC2, COL17A1, ITGA6 and ITGB4 genes. 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.

Suci Widhiati,1,2 Shinta Trilaksmi Dewi,3 Yefta,3 Retno Danarti,3 Hardyanto Soebono,3 Yulia Eka Irmawati,3 Monika Puspitasari,3 Niken Trisnowati,3 Tri Wibawa,4 Dewajani Purnomosari,5 Yohanes Widodo Wirohadidjojo3 1Department of Dermatology and Venereology, Faculty of Medicine, Universitas Sebelas Maret, Surakarta, Indonesia; 2Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia; 3Department of Dermatology and Venereology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia; 4Department of Microbiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia; 5Department of Histology and Cell Biology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, IndonesiaCorrespondence: Yohanes Widodo Wirohadidjojo, Department of Dermatology and Venereology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Gedung Radiopoetro, lt. 3 Sekip, Yogyakarta, 55281, Indonesia, Tel +62 274 560700, Email yohanes.widodo@ugm.ac.idBackground: Autologous non-cultured cell (ANCC) spray has been used to treat burns, chronic wounds, and vitiligo, but its use in junctional epidermolysis bullosa (JEB) has not been published previously. Chronic wounds in JEB are caused by mutations of laminin 332 (L322), whose function is to attach and act as a glue in the basal membrane. It is proposed that ANCC applications can provide keratinocytes and fibroblasts required to improve epithelization and spontaneously correct revertant keratinocytes in the wound area.Purpose: To develop a modified procedure of ANCC spray and improve epithelization using silver sulfadiazine covered with plastic wrap to treat chronic wounds of JEB.Patients and Methods: Shave excision of the donor site was performed on a 19-year-old girl with JEB. The ANCC spray was prepared and applied to the chronic wound, which was then covered with silver sulfadiazine occluded with plastic wrap.Results: Following the ANCC spray application, epithelization was successfully initiated. Unfortunately, the wounds recurred after four months of follow-up.Conclusion: The modified application method of ANCC spray provides a good alternative to treat chronic wounds in JEB.Keywords: revertant mosaicism, silver-sulfadiazine, plastic wrap, chronic wound, junctional epidermolysis bullosa

Junctional epidermolysis bullosa (JEB) is a severe blistering skin disease caused by mutations in genes encoding structural proteins essential for skin integrity. In this study, we developed a cell line suitable for gene expression studies of the JEB-associated COL17A1 encoding type XVII collagen (C17), a transmembrane protein involved in connecting basal keratinocytes to the underlying dermis of the skin. Using the CRISPR/Cas9 system of Streptococcus pyogenes we fused the coding sequence of GFP to COL17A1 leading to the constitutive expression of GFP-C17 fusion proteins under the control of the endogenous promoter in human wild-type and JEB keratinocytes. We confirmed the accurate full-length expression and localization of GFP-C17 to the plasma membrane via fluorescence microscopy and Western blot analysis. As expected, the expression of GFP-C17mut fusion proteins in JEB keratinocytes generated no specific GFP signal. However, the CRISPR/Cas9-mediated repair of a JEB-associated frameshift mutation in GFP-COL17A1mut-expressing JEB cells led to the restoration of GFP-C17, apparent in the full-length expression of the fusion protein, its accurate localization within the plasma membrane of keratinocyte monolayers as well as within the basement membrane zone of 3D-skin equivalents. Thus, this fluorescence-based JEB cell line provides the potential to serve as a platform to screen for personalized gene editing molecules and applications in vitro and in appropriate animal models in vivo. [ABSTRACT FROM AUTHOR]

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 fromher 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. Hematoxylineosin (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. [ABSTRACT FROM AUTHOR]

Junctional epidermolysis bullosa is an intractable cutaneous disorder in humans causing skin fragility and blistering due to mutations in genes encoding essential molecules adhering epidermis and dermis including collagen XVII. However, the pathogenesis still remains to be not fully understood perhaps because of a lack of appropriate animal models. In this study, we report novel mutant rats experiencing junctional epidermolysis bullosa, which was confirmed to be caused by a frameshift mutation of Col17a1 gene, as a rat model for investigating the underlying mechanism of pathogenesis. The mutant rats completely lacked the expression of collagen XVII and had blisters leading to infantile deaths as a homozygous condition, although their skin was apparently normal at birth by light microscopic evaluation except that immunohistochemical examination could not detect collagen XVII in any organs. These observations suggest that collagen XVII is not essential for the development of skin during the prenatal period but is indispensable for keeping epidermal-dermal connections stable after birth. Subsequent electron microscopic examinations further revealed an absence of hemidesmosomal inner plaques being composed of BP230, a binding partner of collagen XVII, and plectin in Col17a1-null newborns, albeit mRNA expressions of these molecules seemed to be unaffected at least during the fetal period. These results suggest that the lack of collagen XVII induces attenuation of hemidesmosomal inner plaques, which in turn destabilizes the epidermis-dermis connection and results in deterioration of epidermal physiology with formation of blisters after birth., (Copyright © 2024 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights reserved.)

Objectives: This study aimed to investigate the genetic etiology of a family affected by junctional epidermolysis bullosa (JEB) and generalized enamel hypoplasia, and to explore how an intronic variant influenced the 5' untranslated region (5'UTR), thereby affecting LAMB3 expression and contributing to the pathogenesis of the disease., Design: Whole-exome and whole-genome sequencing were used to screen for genetic defects in the patient. Mutational consequences were characterized through luciferase assays, splice assay, in silico analyses, and verification using the patient's gingival sample., Results: A nonsense variant (c.2983 C>T; p.Gln995*) and an intronic variant (c.-38+2 T>C) of LAMB3 were identified. In vitro assays demonstrated that the intronic variant activated a cryptic splice site, resulting in a 120 bp intronic inclusion. This splicing alteration significantly reduced the translation efficiency of the downstream coding sequence, while overall mRNA expression remained unaffected. Bioinformatic analysis unveiled the creation of three upstream AUG codons, leading to the presence of two upstream open reading frames (uORFs) and one overlapping ORF. The longer uORF's AUG exhibited a moderate Kozak strength similar to that of the main ORF's AUG. Structural analysis of the mutant 5'UTR sequence revealed a more complex secondary structure, characterized by a large branch loop and a stem-loop preceding the coding sequence's start codon., Conclusion: This study suggests that variants affecting the 5'UTR may contribute to the genetic etiology of JEB. These findings could help enhance the diagnostic accuracy and efficiency in JEB patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Introduction: Introduction: Junctional Epidermolysis Bullosa (JEB) is a rare subtype of the Epidermolysis Bullosa which itself is a rare genetic disorder. While mucosal involvement of pharynx and oesophagus has been reported, laryngeal involvement is rare., Case Report: A 7-month-old male child who was known to have Junctional Epidermolysis Bullosa presented to the emergency department with respiratory distress associated with a stridor which was eventfully found to have multiple level laryngeal stenosis., Conclusions: Longitudinal cohort studies are required to determine the long-term outcome and the anticipated behavior of epidermolysis bullosa in patients with laryngeal manifestation to avoid unnecessary surgical interventions., Competing Interests: we addressed no conflict of interest, and no funding was required., (© 2024 Mashhad University of Medical Sciences.)

Epidermolysis Bullosa (EB) is a group of inherited skin fragility disorders. It characteristically presents as blisters formation over skin and mucosa. Epidermolysis bullosa simplex, junctional epidermolysis bullosa and dystrophic epidermolysis bullosa are three major subtypes of EB depending on the level of skin cleavage. Present case report describes a rare junctional epidermolysis bullosa in a newborn. Clinical manifestations vary from mild local blisters formation to severe one with multisystem involvement. Protection of skin, prevention of complications and supportive care are the only current treatment options.

Resumen: Antecedentes y objetivo: La epidermólisis bullosa (EB) es un grupo heterogéneo de trastornos hereditarios caracterizado por un aumento de la fragilidad mucocutánea. El objetivo del presente estudio es describir las características clínicas y epidemiológicas de los pacientes con EB atendidos en el Hospital Universitario La Paz, centro de referencia nacional para EB hereditaria. Material y método: Estudio observacional, retrospectivo y unicéntrico. Se incluyeron todos los pacientes con diagnóstico clínico y molecular de EB atendidos en el Servicio de Dermatología del Hospital Universitario La Paz desde el 1 de enero de 2000 hasta el 28 de febrero de 2021. Resultados: Se registraron 214 pacientes, con una edad mediana de 17 años (RIQ: 8-32); el 54,2% fueron mujeres. Las formas clínicas correspondieron a EB distrófica con 135 (63,1%) casos, EB simple con 67 (31,3%) casos, EB juntural con ocho (3,7%), EB Kindler con tres (1,4%) casos y EB adquirida con un (0,5%) caso. El 35,5% de los pacientes procedían de Madrid. Las complicaciones clínicas más frecuentes en nuestra serie fueron el prurito (63,1%), las infecciones locales (56,5%) y el dolor (54,7%). Las complicaciones más graves fueron las cardíacas (5,6%) y la aparición de CCE (10,3%). Fallecieron 22 pacientes (10,3%). Conclusiones: La forma clínica predominante fue la EBDR. Las complicaciones más prevalentes fueron el prurito, el dolor y las infecciones, y las más graves, la miocardiopatía y el CCE. Es un estudio pionero realizado en nuestro país que permitirá implementar estrategias para mejorar la situación sociosanitaria de los pacientes con EB. Abstract: Background and objective: Epidermolysis bullosa (EB) is a heterogeneous group of inherited disorders characterized by a high degree of mucocutaneous fragility. This study aimed to describe the clinical and epidemiologic characteristics of patients with EB treated in Hospital Universitario La Paz, a national referral center for inherited EB. Material and methods: Observational, retrospective, single-center study. We included all cases with a clinical and molecular diagnosis of EB managed in the hospital's dermatology department from January 2, 2000, to February 28, 2021. Results: A total of 214 cases were studied. The median (interquartile range) age was 17 (8–32) years; 54.2% were women. One hundred thirty-five (63.1%) patients had dystrophic EB, 67 (31.3%) had EB simplex, 8 (3.7%) had junctional EB, and 3 (1.4%) had Kindler syndrome. One (0.5%) had EB acquisita. Over a third (35.5%) of the patients resided in Madrid. The most common clinical complications were pruritus (63.1%), local infections (56.5%), and pain (54.7%). The most serious ones were cardiomyopathy (in 5.6%) and squamous cell carcinoma (10.3%). Twenty-two patients (10.3%) died. Conclusions: Dystrophic EB was the most prevalent clinical form. The most prevalent complications were pruritus, pain, and infections. The most serious ones were cardiomyopathy and squamous cell carcinoma. This study is the first in Spain that explores strategies for improving the health status and quality of life of patients with EB.

Junctional epidermolysis bullosa (JEB) patients experience skin and epithelial fragility due to a pathological deficiency in genes associated with epidermal adhesion. Disease severity ranges from post-natal lethality to localized skin involvement with persistent blistering followed by granulation tissue formation and atrophic scarring. We evaluated the potential of utilizing Trametinib, an MEK inhibitor previously shown to target fibrosis, with and without the documented EB-anti-fibrotic Losartan for reducing disease severity in a mouse model of JEB; Lamc2jeb mice. We found that Trametinib treatment accelerated disease onset and decreased epidermal thickness, which was in large part ameliorated by Losartan treatment. Interestingly, a range of disease severity was observed in Trametinib-treated animals that tracked with epidermal thickness; those animals grouped with higher disease severity had thinner epidermis. To examine if the difference in severity was related to inflammation, we conducted immunohistochemistry for the immune cell markers CD3, CD4, CD8, and CD45 as well as the fibrotic marker αSMA in mouse ears. We used a positive pixel algorithm to analyze the resulting images and demonstrated that Trametinib caused a non-significant reduction in CD4 expression that inversely tracked with increased fibrotic severity. With the addition of Losartan to Trametinib, CD4 expression was similar to control. Together, these data suggest that Trametinib causes a reduction in both epidermal proliferation and immune cell infiltration/proliferation, with concurrent acceleration of skin fragility, while Losartan counteracts Trametinib’s adverse effects in a mouse model of JEB.

Junctional epidermolysis bullosa (JEB) is a severe blistering skin disease caused by mutations in genes encoding structural proteins essential for skin integrity. In this study, we developed a cell line suitable for gene expression studies of the JEB-associated COL17A1 encoding type XVII collagen (C17), a transmembrane protein involved in connecting basal keratinocytes to the underlying dermis of the skin. Using the CRISPR/Cas9 system of Streptococcus pyogenes we fused the coding sequence of GFP to COL17A1 leading to the constitutive expression of GFP-C17 fusion proteins under the control of the endogenous promoter in human wild-type and JEB keratinocytes. We confirmed the accurate full-length expression and localization of GFP-C17 to the plasma membrane via fluorescence microscopy and Western blot analysis. As expected, the expression of GFP-C17mut fusion proteins in JEB keratinocytes generated no specific GFP signal. However, the CRISPR/Cas9-mediated repair of a JEB-associated frameshift mutation in GFP-COL17A1mut-expressing JEB cells led to the restoration of GFP-C17, apparent in the full-length expression of the fusion protein, its accurate localization within the plasma membrane of keratinocyte monolayers as well as within the basement membrane zone of 3D-skin equivalents. Thus, this fluorescence-based JEB cell line provides the potential to serve as a platform to screen for personalized gene editing molecules and applications in vitro and in appropriate animal models in vivo.

Epidermolysis bullosa (EB) is a rare heterogeneous genetic mechanobullous skin disorder that is characterized by increased skin fragility leading to blistering following minor trauma. EB may be inherited as an autosomal dominant or an autosomal recessive disorder and can be classified into dystrophic EB (DEB), junctional EB (JEB), and EB simplex (EBS). A total of 28 Saudi patients with EB were included in this observational, retrospective chart-review study. A consecutive non-probability sampling technique was used to approach all affected patients. Molecular analysis was done to test the patients' genomic DNA using a custom-designed AmpliSeq panel of suspected genes. All disease-causing variants were checked against available public databases. Twelve patients (42.9%) were found to have DEB, 6 patients (21.4%) with JEB, and 10 patients (35.7%) with EBS. The molecular genetic results revealed detections of 24 various homozygous genetic variations in the genes associated with EB, of which 14 were novel mutations. The most frequent variations were detected in COL7A1 in 12 cases (42.9%), followed by LAMB3 in 5 cases (17.9%), TGM5 in 4 cases (14.3%), and other genes. Furthermore, the majority (87.5%) of EB cases were confirmed to have homozygous mutations, and few were documented with positive consanguinity history. Only 3 cases (12.5%) were found to be autosomal dominant displaying heterozygous mutations. This is the first study to establish the EB genetic profile in Saudi Arabia where DEB is the most frequent type. A total of 14 novel mutations were identified that had not been previously reported. Consanguineous marriage is clearly recognized in the Saudi population; therefore, we propose a nationwide EB program that would help extend the spectrum of the genetic profile and help in the diagnosis and better understanding of this disease. [ABSTRACT FROM AUTHOR]

Junctional epidermolysis bullosa (JEP) is a heritable skin and mucosa disorder in association with mendelian mutations in sheep. The purpose of this investigation is to explore the relationship between different priors, linkage disequilibrium, and single nucleotide polymorphism (SNP) selection methods and accuracy of Bayesian GP of JEP in sheep. Ninety-two Spanish Churra sheep breed genotyped by 40668 SNP markers. Bayes Cπ was shown to have slightly higher predicted accuracy [0.724 (0.113)] by unselected data. Prediction performance of the Bayesian GP models was found to be similar after correction for LD. There was a significant difference between predicted accuracies due to the SNP selection by ranked p values of whole and training only dataset using linear model. The relevance of genetic architecture in conjugate to the prior distributions was clearly supported by the unselected data. The most obvious finding of this study is that preselection of SNPs referring to genetic architecture of the phenotype may lower the needs of computational load. [ABSTRACT FROM AUTHOR]

Background: Junctional epidermolysis bullosa (JEB) is an autosomal recessive skin disorder with defective adhesion of dermal- epidermal within the lamina lucida region of the basement membrane zone. The main characterization of JEB is blistering and fragile skin and mucous membrane. Laminins are noncollagenous part of basement membrane and classified as a family of extracellular matrix glycoprotein. Laminins contain three chains: Laminin α, Laminin β and Laminin γ. LAMC2 (laminin subunit gamma 2) gene encodes γ subunit of laminin and its mutation contributes to JEB. Here, we report a disease-causing nonsense mutation and a large deletion mutation in LAMC2 gene in two families affected by JEB. Methods: Whole exome sequencing (WES) was carried out on the mother of patient in family I and the patient himself in family II to detect the underlying mutations. Then, sanger sequencing was performed to confirm the identified mutations. Results: Next generation sequencing (NGS) data analysis of the first family showed a novel, nonsense mutation in LAMC2 gene (LAMC2: NM_005562: exon14:c.C2143T: p.R715X). The heterozygous state of the mutation was confirmed by sanger sequencing in the parents and unaffected brother. In Family II, NGS data had no coverage in the large area of LAMC2 gene. Thus, to confirm the possible deletion sanger sequencing was done and blasting of sequence showed the deleted region of 9.4 kb (exon10-17) in LAMC2 gene. Conclusions: In summary, current study reported a novel disease-causing premature termination codon (PTC) mutation in LAMC2 gene and a large deletion mutation in patients affected by JEB. [ABSTRACT FROM AUTHOR]

Abstract Background Aplasia cutis congenita (ACC), classified in nine groups, is likely to be underreported, since milder isolated lesions in wellbeing newborns could often be undetected, and solitary lesions in the context of polymalformative syndromes could not always be reported. Regardless of form and cause, therapeutic options have in common the aim to restore the deficient mechanical and immunological cutaneous protection and to limit the risk of fluid leakage or rupture of the exposed organs. We aimed to review our institutional prevalence, comorbidities, treatment and outcome of newborns with ACC. Methods We conducted a retrospective study including all newborns affected by ACC and admitted at the University Mother-Child Department from October 2010 to October 2019. Anthropometric and clinical characteristics of ACC1 versus a non-isolated ACC group were analyzed. Results We encountered 37 newborns, 16 with ACC1 versus 21 with non-isolated ACC. The incidence rate of 0.1% in ACC1 was higher than expected, while 19% of cases showed intrafamilial autosomal dominant transmission. Higher birth weight centile, though lower than reference population, being adequate for gestational age, normal Apgar score and euglycemia characterizing ACC1 resulted associated to a rapid tissue regeneration. Non-isolated ACC, in relation to concomitant congenital anomalies and higher prematurity rate, showed more surgical and medical complications along with the risk of neonatal death. Specifically, newborns with ACC4 were characterized by the frequent necessity of abdominal wall defect repair, responsible for the occurrence of an abdominal compartment syndrome. Conclusion Prompt carefully assessment of the newborn with ACC in order to exclude concomitant other congenital malformations, provides clues to the underlying pathophysiology, and to the short-term prognosis. Family should be oriented toward identification of other family members affected by similar pathology, while obstetric history should exclude initial multiple pregnancy with death of a co-twin, placental anomalies and drug assumption. Molecular-genetic diagnosis and genetic counseling are integrative in individualized disease approach.

Epidermolysis bullosa (EB) is a rare heterogeneous genetic mechanobullous skin disorder that is characterized by increased skin fragility leading to blistering following minor trauma. EB may be inherited as an autosomal dominant or an autosomal recessive disorder and can be classified into dystrophic EB (DEB), junctional EB (JEB), and EB simplex (EBS). A total of 28 Saudi patients with EB were included in this observational, retrospective chart-review study. A consecutive non-probability sampling technique was used to approach all affected patients. Molecular analysis was done to test the patients’ genomic DNA using a custom-designed AmpliSeq panel of suspected genes. All disease-causing variants were checked against available public databases. Twelve patients (42.9%) were found to have DEB, 6 patients (21.4%) with JEB, and 10 patients (35.7%) with EBS. The molecular genetic results revealed detections of 24 various homozygous genetic variations in the genes associated with EB, of which 14 were novel mutations. The most frequent variations were detected in COL7A1 in 12 cases (42.9%), followed by LAMB3 in 5 cases (17.9%), TGM5 in 4 cases (14.3%), and other genes. Furthermore, the majority (87.5%) of EB cases were confirmed to have homozygous mutations, and few were documented with positive consanguinity history. Only 3 cases (12.5%) were found to be autosomal dominant displaying heterozygous mutations. This is the first study to establish the EB genetic profile in Saudi Arabia where DEB is the most frequent type. A total of 14 novel mutations were identified that had not been previously reported. Consanguineous marriage is clearly recognized in the Saudi population; therefore, we propose a nationwide EB program that would help extend the spectrum of the genetic profile and help in the diagnosis and better understanding of this disease.

Epidermolysis bullosa (EB) is a genetic skin disorder characterized by skin fragility and blister formation. This review explores the genetic basis and management of EB in the Saudi population, emphasizing the need for genetic insights to enable precise diagnosis, targeted treatments, and effective counseling. Diagnosis in Saudi Arabia relies on clinical assessments and genetic testing. Prenatal diagnosis may be suggested in families with children affected by EB, but it is not widely used in the Middle East. Current management focuses on symptom relief, while emerging experimental approaches such as gene and stem cell therapies are under extensive research. Challenges in EB research include developing effective targeted therapies and understanding the variability in how genotypes manifest phenotypically. Continuous research is crucial to enhance diagnostic methods, therapeutic approaches, and overall patient care., Competing Interests: Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Shehata et al.)

Background: Junctional epidermolysis bullosa (JEB) is one of the four major types of EB caused by genetic variants in the genes coding the proteins of the lamina lucida. All patients with this major type of EB present syndromic hypoplastic amelogenesis imperfecta (AI), with either a pits and fissures or generalized hypoplastic phenotype. Severe forms of AI are associated with compromised oral health-related quality of life (QoL) mostly due to poor dental aesthetics, dentofacial anomalies, and oral pain., Aim: To present the comprehensive dental treatment of a patient with JEB and AI from the age of 20 months until the age of 18 years, including complex orthodontics and digital oral rehabilitation., Materials and Methods: A male patient with intermediate JEB (homozygous c.3228+1G>A LAMB3 variant) has been under the care of the special care dentistry clinic of the University of Chile since the age of 20 months. His complex dental needs include structural enamel abnormalities in primary and permanent dentition (hypoplastic generalized AI), severe dental crowding with maxillary compression, Class III skeletal pattern, agenesia (#45), and gingivitis., Results: Pediatric dental care included oral hygiene education and preventive strategies (prophylaxis and fluoride applications), maintaining the dentition free of caries. Due to AI, severe tooth sensitivity hindered proper oral hygiene and required early rehabilitation with temporary polycarbonate and metallic crowns. At the age of 16, the patient began orthodontic treatment. A maxillary expansion was performed with two consecutive mini-implant assisted rapid palate expansion (MARPE) bonded to four mini-implants in the palate. After finishing orthodontic treatment metallic multibrackets (duration 19 months), a definitive oral rehabilitation based on digital smile design with feldspathic crowns of all anterior teeth and premolars was performed., Conclusion: Patients with severe generalized hypoplastic syndromic AI associated with JEB benefit from long-term preventive oral care. Complex orthodontic techniques, such as MARPE, and multibrackets can be successfully. Digital smile design provides a definitive oral rehabilitation technique improving oral function, aesthetics, and QoL., (© 2024 The Author(s). Special Care in Dentistry published by Special Care Dentistry Association and Wiley Periodicals LLC.)

Epidermolysis bullosa (EB) is a heterogeneous group of genetic disorders characterized by the formation of blisters either spontaneously or at the sites of trauma. These heal with post-inflammatory hypopigmentation, scarring, or milia formation. We hereby present a child who presented with widespread hypopigmented atrophic areas, blistering at trauma-prone sites, and nail dystrophy. The significance of this particular case lies in the challenge of distinguishing between epidermolysis bullosa and bullous extragenital lichen sclerosus et atrophicus., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Indian Dermatology Online Journal.)

Introduction: Epidermolysis bullosa (EB) is a rare genetic skin disorder inherited either in autosomal recessive (AR) or autosomal dominant (AD) manner and characterized by blistering of the skin and mucous membranes. According to a subtype of EB, the oral manifestations and dental involvement vary in frequency and in severity. The most severe dental problems occur in patients with junctional epidermolysis bullosa (JEB) and severe generalized dystrophic epidermolysis bullosa (RDEB) and involve enamel erosion and development of blisters followed by painful oral wounds. Oral mucosa lesions decrease patients' quality of life and may contribute to difficulties in nutrition leading to cachexia. Aim: Assessment of efficacy of gentamicin 0.3% solution in the healing and preventing of oral erosions in patients with RDEB and evaluating its impact on the expression of type VII collagen. Material and methods: The study included four female patients with RDEB, aged 16-42 who show different mutations in the COL7A1 gene and were administered the mouth rinse two times daily with a solution of 0.3% gentamycin for 4 consecutive weeks. Prior to and at the end of the study, the samples from oral mucosa were collected to estimate the expression of type VII collagen by immunofluorescence test. Results: The clinical improvement of oral wounds healing and reduced number of new blisters and mucous membrane soreness as well as partial re-expression of type VII collagen was observed in all studied patients. Conclusions: Topical gentamicin therapy of oral cavity in RDEB patients resulted in clinical improvement of mucosal lesions and re-expression of collagen type VII. [ABSTRACT FROM AUTHOR]

Background: 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.Case Report: The study was conducted on a 10-year-old patient with JEB carrier of two recessive mutations in the LAMB3 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.Conclusion: 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 LAMB3 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.

The laminins (LM) are a family of basement membranes glycoproteins with essential structural roles in supporting epithelia, endothelia, nerves and muscle adhesion, and signaling roles in regulating cell migration, proliferation, stem cell maintenance and differentiation. Laminins are obligate heterotrimers comprised of α, β and γ chains that assemble intracellularly. However, extracellularly these heterotrimers then assemble into higher-order networks via interaction between their laminin N-terminal (LN) domains. In vitro protein studies have identified assembly kinetics and the structural motifs involved in binding of adjacent LN domains. The physiological importance of these interactions has been identified through the study of pathogenic point mutations in LN domains that lead to syndromic disorders presenting with phenotypes dependent on which laminin gene is mutated. Genotype-phenotype comparison between knockout and LN domain missense mutations of the same laminin allows inferences to be drawn about the roles of laminin network assembly in terms of tissue function. In this review, we will discuss these comparisons in terms of laminin disorders, and the therapeutic options that understanding these processes have allowed. We will also discuss recent findings of non-laminin mediators of laminin network assembly and their implications in terms of basement membrane structure and function.

The laminins (LM) are a family of basement membranes glycoproteins with essential structural roles in supporting epithelia, endothelia, nerves and muscle adhesion, and signaling roles in regulating cell migration, proliferation, stem cell maintenance and differentiation. Laminins are obligate heterotrimers comprised of α, β and γ chains that assemble intracellularly. However, extracellularly these heterotrimers then assemble into higher-order networks via interaction between their laminin N-terminal (LN) domains. In vitro protein studies have identified assembly kinetics and the structural motifs involved in binding of adjacent LN domains. The physiological importance of these interactions has been identified through the study of pathogenic point mutations in LN domains that lead to syndromic disorders presenting with phenotypes dependent on which laminin gene is mutated. Genotype-phenotype comparison between knockout and LN domain missense mutations of the same laminin allows inferences to be drawn about the roles of laminin network assembly in terms of tissue function. In this review, we will discuss these comparisons in terms of laminin disorders, and the therapeutic options that understanding these processes have allowed. We will also discuss recent findings of non-laminin mediators of laminin network assembly and their implications in terms of basement membrane structure and function. [ABSTRACT FROM AUTHOR]

Background: ILNEB constitute an autosomal recessive disorder caused by homozygous or compound heterozygous mutation of the gene for the ITGA3. To date, 8 ILNEB patients have been reported, but all 6 neonatal‐onset ILNEB patients suffered early death within 2 years. The most common cause of death among previously reported ILNEB patients was exacerbation of the respiratory condition. Methods: In this study, we describe a case of ILNEB with neonatal onset in a female patient and the genetic and histopathological testing performed. Results: Our patient had a compound heterozygous mutation in ITGA3. Compared to previously reported patients, this patient exhibited milder clinical and histopathological characteristics. After experiencing a life‐threatening respiratory infection at 8 months old, the patient started periodic subcutaneous immunoglobulin treatment once every 1‐2 weeks for nephrotic‐range proteinuria‐induced secondary hypogammaglobulinemia. At the age of 3 years, proteinuria gradually increased with severe edema despite strict internal management. Therefore, our patient underwent unilateral nephrectomy and insertion of a peritoneal dialysis catheter followed by another unilateral nephrectomy. One month later, she underwent an ABO‐compatible living‐donor kidney transplantation at the age of 4 years. Conclusions: Our patient is a neonatal‐onset ILNEB patient who survived for more than 2 years and underwent successful kidney transplantation. [ABSTRACT FROM AUTHOR]

Epidermolysis bullosa (EB) comprises a group of genetically determined skin fragility disorders, characterized by blistering of the skin and mucosae following mechanical trauma, which includes four major forms (EB simplex, junctional EB [JEB], dystrophic EB, and Kindler syndrome) with various distinctive clinical phenotypes. We report a rare case of a 15-year-old female diagnosed as JEB (generalized intermediate), with the help of immunofluorescence antigen mapping.

Laryngo-onycho-cutaneous (LOC) first described by Shabbir in 1986 in Muslim families from Punjab is a rare autosomal recessive disorder characterized by increased skin and mucous membrane fragility associated with exuberant granulation. The 4th International Consensus Meeting on “Diagnosis and Classification of Epidermolysis Bullosa” classifies it as a localized form of Junctional Epidermolysis Bullosa (JEB-LOC Syndrome) with mutations in α3 chain of Laminin 332. While laryngeal, ocular, and cutaneous involvement in these cases has been widely reported, urinary tract involvement is relatively rare. We report a case of JEB-LOC syndrome in a child from South India with extensive urethral involvement.

CR McDonald, K Plevey, G Petrof, AE Martinez Paediatric Dermatology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UKCorrespondence: AE MartinezPaediatric Dermatology, Great Ormond Street Hospital for Children NHS Foundation Trust London, WC1N 3JH, UKTel +207 829 780Email Anna.martinez@gosh.nhs.ukAbstract: Epidermolysis bullosa (EB) is a group of rare genetic mucocutaneous fragility disorders. Patients with EB can experience blister formation following minor skin trauma, which can progress to chronic wounds. These wounds can be painful and difficult to manage. There are four major types of EB which are defined by the defective protein and the layer within the skin this protein is located. Junctional epidermolysis bullosa (JEB) is caused by mutations within the lamina lucida proteins which are located at the dermoepidermal junction. The prognosis of JEB varies considerably between the different subtypes of JEB, with JEB generalised severe being the most severe, with high mortality within the first 2 years of life. On the opposite end, patients with JEB localised would be expected to have normal life expectancy. In this review, we discuss the management of chronic wounds in paediatric patients with JEB, including suitable wound cleansing, recommended dressings and topical preparations for chronic wound treatments. We include chronic wounds over specific anatomical sites which are frequent in patients with JEB and their recommended management. Important differences between the subtypes of JEB, and specifics on dressings suitable in the neonatal and infancy period are highlighted. Symptom care of wounds in these children, such as pain, infection, pruritus and overgranulation are also addressed. Finally, we highlight the changes to practice which have occurred in recent years and novel treatments which have been trialled and can be considered.Keywords: junctional epidermolysis bullosa, paediatric JEB, wound management

Background: Epidermolysis bullosa (EB) is a rare hereditary skin disease. It is subdivided into EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB) and Kindler syndrome. JEB is diagnosed in 2 per 1,000,000 of the population. There are few descriptions of clinical JEB cases in the literature. Clinical diagnosis of JEB and its subtypes is a challenge, especially in the early age. The paper presents 2 clinical cases of JEB in patients of the West Slavonic origin. Clinical case No. 1 was a girl of Ukrainian ethnicity, with confirmed definitive diagnosis of severe generalized JEB. Molecular genetic tests identified mutations of the LAMA3 gene that had not been described previously. The patient died at the age of 24 months from acute respiratory failure. When the patient was alive, her EB type and subtype was not possible to identify, because she had a combination of clinical manifestations typical for various JEB subtypes. Despite such symptoms as hoarse voice, stenoses, granulation tissue of typical location, laryngeal granulations, the girl was steadily gaining weight, with some periods of relative stabilization of the skin disease; she also had longer life longevity than was common for patients with severe generalized JEB. All this made a precise diagnosis difficult. Clinical case No. 2: an ethnic Russian boy with non-classified JEB. Molecular genetic testing helped to identify a homozygote mutation in the LAMA3 gene that had not been previously described; reliable determination of the subtype was not possible. The patient had mixed clinical manifestation similar both to generalized severe JEB and to laryngo-onycho-cutaneous (LOC) syndrome. During his lifetime, the patient was clinically diagnosed with Hallopeau acrodermatitis and LOC syndrome. The differential diagnostic problems were associated with the presence of signs not typical for each of the subtypes. Significant life longevity of the proband is not characteristic for severe generalized JEB (at the time of the publication the patient is 13 years old), whereas for LOC syndrome the absence of eye involvement is not typical, as well as severe laryngeal involvement at adolescence.Conclusion: Detailed descriptions of phenotype of JEB subtypes including rare and minimal clinical signs can be useful to study the clinical manifestations and natural course of the disease, including its differential diagnosis.

Background: Collagen XVII is most typically associated with human disease when biallelic COL17A1 variants (>230) cause junctional epidermolysis bullosa (JEB), a rare, genetically heterogeneous, mucocutaneous blistering disease with amelogenesis imperfecta (AI), a developmental enamel defect. Despite recognition that heterozygous carriers in JEB families can have AI, and that heterozygous COL17A1 variants also cause dominant corneal epithelial recurrent erosion dystrophy (ERED), the importance of heterozygous COL17A1 variants causing dominant non-syndromic AI is not widely recognised., Methods: Probands from an AI cohort were screened by single molecule molecular inversion probes or targeted hybridisation capture (both a custom panel and whole exome sequencing) for COL17A1 variants. Patient phenotypes were assessed by clinical examination and analyses of affected teeth., Results: Nineteen unrelated probands with isolated AI (no co-segregating features) had 17 heterozygous, potentially pathogenic COL17A1 variants, including missense, premature termination codons, frameshift and splice site variants in both the endo-domains and the ecto-domains of the protein. The AI phenotype was consistent with enamel of near normal thickness and variable focal hypoplasia with surface irregularities including pitting., Conclusion: These results indicate that COL17A1 variants are a frequent cause of dominantly inherited non-syndromic AI. Comparison of variants implicated in AI and JEB identifies similarities in type and distribution, with five identified in both conditions, one of which may also cause ERED. Increased availability of genetic testing means that more individuals will receive reports of heterozygous COL17A1 variants. We propose that patients with isolated AI or ERED, due to COL17A1 variants, should be considered as potential carriers for JEB and counselled accordingly, reflecting the importance of multidisciplinary care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)