Revised clinical and laboratory criteria for subtypes of inherited epidermolysis bullosa. A consensus report by the Subcommittee on Diagnosis and Classification of the National Epidermolysis Bullosa Registry

Systematic review on antipruritic therapies for patients with Epidermolysis bullosa

INTRODUCTION

Itch is one of the most burdensome symptoms in epidermolysis bullosa (EB), indicating a hitherto unmet therapeutic need. This review leverages existing data on efficacy of itch treatment in EB to support sound decision making.

METHODS

A systematic literature search was performed on 29 March 2022. Studies written later than 1991 and reporting outcomes in patients with EB treated for itch were considered.

RESULTS

Of the 3,099 articles screened, 21 studies met eligibility criteria, comprising 353 patients (65.9%) diagnosed for recessive dystrophic EB. Only two studies (9.5%) evaluated itch as primary endpoint, of which solely one revealed a significant relief of self-reported itch upon topical skin care. In those studies assessing itch as secondary endpoint (19/21, 90.5%), only 36.8% studies (n = 7/19) revealed a statistically significant itch reduction of up to 42%. Methodological limitations (heterogeneity of outcomes, inconsistent data assessment) in addition to limited superiority over control were implicated to account for low treatment efficacy observed in most studies.

CONCLUSION

Current data quality impairs comparative efficacy analyses of itch treatments in EB. Large scale randomized clinical trials and more personalized approaches applying validated measurement instruments for core outcomes are needed to substantiate evidence-based treatment approaches for EB-associated itch.

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.

Heterogeneity of reported outcomes in epidermolysis bullosa clinical research: a scoping review as a first step towards outcome harmonization

BACKGROUND

Epidermolysis bullosa (EB) is a rare, genetically and clinically heterogeneous group of skin fragility disorders. No cure is currently available, but many novel and repurposed treatments are upcoming. For adequate evaluation and comparison of clinical studies in EB, well-defined and consistent consensus-endorsed outcomes and outcome measurement instruments are necessary.

OBJECTIVES

To identify previously reported outcomes in EB clinical research, group these outcomes by outcome domains and areas and summarize respective outcome measurement instruments.

METHODS

A systematic literature search was performed in the databases MEDLINE, Embase, Scopus, Cochrane CENTRAL, CINAHL, PsycINFO and trial registries covering the period between January 1991 and September 2021. Studies were included if they evaluated a treatment in a minimum of three patients with EB. Two reviewers independently performed the study selection and data extraction. All identified outcomes and their respective instruments were mapped onto overarching outcome domains. The outcome domains were stratified according to subgroups of EB type, age group, intervention, decade and phase of clinical trial.

RESULTS

The included studies (n = 207) covered a range of study designs and geographical settings. A total of 1280 outcomes were extracted verbatim and inductively mapped onto 80 outcome domains and 14 outcome areas. We found a steady increase in the number of published clinical trials and outcomes reported over the past 30 years. The included studies mainly focused on recessive dystrophic EB (43%). Wound healing was reported most frequently across all studies and referred to as a primary outcome in 31% of trials. Great heterogeneity of reported outcomes was observed within all stratified subgroups. Moreover, a diverse range of outcome measurement instruments (n = 200) was identified.

CONCLUSIONS

We show substantial heterogeneity in reported outcomes and outcome measurement instruments in EB clinical research over the past 30 years. This review is the first step towards harmonization of outcomes in EB, which is necessary to expedite the clinical translation of novel treatments for patients with EB.

Allele-Specific Inactivation of an Autosomal Dominant Epidermolysis Bullosa Simplex Mutation Using CRISPR-Cas9

Epidermolysis bullosa simplex (EBS) is a rare mechanobullous disease caused by dominant-negative mutations in either keratin 5 (KRT5) or keratin 14 (KRT14) genes. Until now, there is no cure for EBS and the care is primarily palliative. The discovery of the clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 system raised hope for the treatment of EBS and many other autosomal dominant diseases by mutant allele-specific gene disruption. In this study, we aim to disrupt the mutant allele for the heterozygous EBS pathogenic variation c.449T>C (p.Leu150Pro) within KRT5. This mutation generates, naturally, a novel protospacer-adjacent motif for the endonuclease Streptococcus pyogenes Cas9. Thus, we designed a single-guide RNA that guides the Cas9 to introduce a DNA cleavage of the mutant allele in patient's keratinocytes. Then, transfected cells were single-cell cloned and analyzed by deep sequencing. The expression of KRT5 and KRT14 was quantified, and the keratin intermediate filament stability was assessed. Results showed successful stringent mutant allele-specific knockout. An absence of synthesis of mutant transcript was further confirmed indicating permanent mutant allele-specific inactivation. Edited EBS patient keratinocytes produced a lower amount of K5 and K14 proteins compared with nonedited EBS cells, and no disturbance of cellular properties was observed.

A retrospective analysis of diagnostic testing in a large North American cohort of patients with epidermolysis bullosa

BACKGROUND

Accurate diagnosis of epidermolysis bullosa (EB) has significant implications for prognosis, management, and genetic counseling.

OBJECTIVE

To describe diagnostic testing patterns and assess diagnostic concordance of transmission electron microscopy (TEM), immunofluorescence mapping (IFM), and genetic analysis for EB.

METHODS

A retrospective cohort included patients enrolled in the Epidermolysis Bullosa Clinical Characterization and Outcomes Database from January 1, 2004, to July 8, 2019. Tests concluding the same EB type (EB simplex, junctional EB, dominant dystrophic EB, and recessive dystrophic EB) were considered concordant; those concluding different EB types were considered discordant; and those with nonspecific/nondefinitive results were equivocal.

RESULTS

A total of 970 diagnostic tests were conducted from 1984 to 2018 in 771 patients. Genetic analyses were performed chronologically later than IFM or TEM (P < .001). The likelihood of undergoing genetic analysis was greater for junctional EB and recessive dystrophic EB, and the same for dominant dystrophic EB as compared with EB simplex. TEM results in 163 patients were equivocal (55%), concordant (42%), and discordant (3%). IFM results in 185 patients were equivocal (54%), concordant (42%), and discordant (4%).

LIMITATIONS

Retrospective design.

CONCLUSIONS

Diagnostic testing has shifted in favor of genetic analysis. TEM and IFM frequently offer equivocal findings when compared to the specificity afforded by genetic analysis.

Clinical practice guidelines: Oral health care for children and adults living with epidermolysis bullosa

BACKGROUND

Inherited epidermolysis bullosa (EB) is a genetic disorder characterized by skin fragility and unique oral features.

AIMS

To provide (a) a complete review of the oral manifestations in those living with each type of inherited EB, (b) the current best practices for managing oral health care of people living with EB, (c) the current best practices on dental implant-based oral rehabilitation for patients with recessive dystrophic EB (RDEB), and (d) the current best practice for managing local anesthesia, principles of sedation, and general anesthesia for children and adults with EB undergoing dental treatment.

METHODS

Systematic literature search, panel discussion including clinical experts and patient representatives from different centers around the world, external review, and guideline piloting.

RESULTS

This article has been divided into five chapters: (i) general information on EB for the oral health care professional, (ii) systematic literature review on the oral manifestations of EB, (iii) oral health care and dental treatment for children and adults living with EB-clinical practice guidelines, (iv) dental implants in patients with RDEB-clinical practice guidelines, and (v) sedation and anesthesia for adults and children with EB undergoing dental treatment-clinical practice guidelines. Each chapter provides recommendations on the management of the different clinical procedures within dental practice, highlighting the importance of patient-clinician partnership, impact on quality of life, and the importance of follow-up appointments. Guidance on the use on nonadhesive wound care products and emollients to reduce friction during patient care is provided.

CONCLUSIONS

Oral soft and hard tissue manifestations of inherited EB have unique patterns of involvement associated with each subtype of the condition. Understanding each subtype individually will help the professionals plan long-term treatment approaches.

Inherited epidermolysis bullosa: update on the clinical and genetic aspects

Inherited epidermolysis bullosa is a group of genetic diseases characterized by skin fragility and blistering on the skin and mucous membranes in response to minimal trauma. Epidermolysis bullosa is clinically and genetically very heterogeneous, being classified into four main types according to the layer of skin in which blistering occurs: epidermolysis bullosa simplex (intraepidermal), junctional epidermolysis bullosa (within the lamina lucida of the basement membrane), dystrophic epidermolysis bullosa (below the basement membrane), and Kindler epidermolysis bullosa (mixed skin cleavage pattern). Furthermore, epidermolysis bullosa is stratified into several subtypes, which consider the clinical characteristics, the distribution of the blisters, and the severity of cutaneous and extracutaneous signs. Pathogenic variants in at least 16 genes that encode proteins essential for the integrity and adhesion of skin layers have already been associated with different subtypes of epidermolysis bullosa. The marked heterogeneity of the disease, which includes phenotypes with a broad spectrum of severity and many causal genes, hinders its classification and diagnosis. For this reason, dermatologists and geneticists regularly review and update the classification criteria. This review aimed to update the state of the art on inherited epidermolysis bullosa, with a special focus on the associated clinical and genetic aspects, presenting data from the most recent reclassification consensus, published in 2020.

Validity of first-time diagnoses of congenital epidermolysis bullosa in the Danish National Patient Registry and the Danish Pathology Registry

Purpose

Congenital epidermolysis bullosa (CEB) is a group of rare monogenic genodermatoses. Phenotypically, the diseases vary in both severity and dissemination, which complicates studies of their epidemiology. To investigate the potential of using the Danish National Patient Registry (DNPR) for epidemiological research on CEB, we examined the positive predictive value (PPV) of a first-time diagnosis of CEB.

Methods

We identified patients with a record of CEB in DNPR and the Danish Pathology Registry (DPR) during January 1, 1977, until December 31, 2015. We restricted diagnoses from two dermatological departments and one regional hospital. Diagnoses in the DNPR are coded by the eighth and tenth revisions of the ICD (ICD-8 and ICD-10) and in the DPR by the Systematized Nomenclature of Medicine (SNOMED). We used clinical description in medical records, family history, histological findings, and molecular genetic investigations to validate diagnoses and classified them as rejected and confirmed. We estimated PPVs for any diagnosis, according to coding systems used, and for additional subdivisions of ICD-10 codes.

Results

We identified 116 cases from the hospital departments investigated and evaluated 96 medical records for validity. The overall PPV for probable CEB was 62.5% (95% CI: 52.5–71.5). For ICD-8, ICD-10, and SNOMED codes, the PPVs were 30.8% (95% CI: 11.4–57.7), 76.7% (95% CI: 65.8–84.9), and 0.0% (95% CI: 0.0–21.7), respectively. For the ICD-10 codes, we found the highest PPVs for diagnoses arising from the dermatological departments. For subdivisions of ICD-10 codes, PPVs were high for epidermolysis bullosa simplex and dystrophica.

Conclusion

The PPVs for first-time diagnoses of CEB registered in the two Danish nationwide registries investigated, DNPR and DPR, ranged from low to average. We therefore recommend that these data be used with caution and restricted to ICD-10 diagnoses from specialized dermatological departments.

Discovery of keratin function and role in genetic diseases: the year that 1991 was

In 1991, a set of transgenic mouse studies took the fields of cell biology and dermatology by storm in providing the first credible evidence that keratin intermediate filaments play a unique and essential role in the structural and mechanical support in keratinocytes of the epidermis. Moreover, these studies intimated that mutations altering the primary structure and function of keratin filaments underlie genetic diseases typified by cellular fragility. This Retrospective on how these studies came to be is offered as a means to highlight the 25th anniversary of these discoveries.

Pseudosyndactyly and Musculoskeletal Contractures in Inherited Epidermolysis Bullosa: Experience of the National Epidermolysis Bullosa Registry, 1986–2002

Mitten deformities of the hands and feet occur in nearly every patient with the most severe subtype (Hallopeau-Siemens) of recessive dystrophic epidermolysis bullosa, and in at least 40–50% of all other recessive dystrophic epidermolysis bullosa patients. Smaller numbers of patients with dominant dystrophic, junctional, and simplex types of epidermolysis bullosa are also at risk of this complication. Surgical intervention is commonly performed to correct these deformities, but recurrence and the need for repeated surgery are common. Higher numbers of epidermolysis bullosa patients also develop musculoskeletal contractures in other anatomic sites, further impairing overall function. Lifetable analyses not only better project the cumulative risk of mitten deformities and other contractures but also emphasize the need for early surveillance and intervention, since both of these musculoskeletal complications may occur within the first year of life.

Dystrophic epidermolysis bullosa: a review

Dystrophic epidermolysis bullosa is a rare inherited blistering disorder caused by mutations in the COL7A1 gene encoding type VII collagen. The deficiency and/or dysfunction of type VII collagen leads to subepidermal blistering immediately below the lamina densa, resulting in mucocutaneous fragility and disease complications such as intractable ulcers, extensive scarring, malnutrition, and malignancy. The disease is usually diagnosed by immunofluorescence mapping and/or transmission electron microscopy and subsequently subclassified into one of 14 subtypes. This review provides practical knowledge on the disease, including new therapeutic strategies.

MMP13 can be a useful differentiating marker between squamous cell carcinoma and benign hyperkeratotic lesions in recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe hereditary mechanobullous disease resulting from mutations in the COL7A1 gene, coding for type VII collagen. Patients with RDEB tend to develop squamous cell carcinomas (SCCs) at sites of chronic ulceration or scarring on the whole body. Distinguishing SCC from benign hyperkeratotic lesions is often difficult, not only clinically but also histologically in patients with RDEB. We investigated several matrix metallopeptidase (MMP) subtypes by comparing the DNA amplification microarray findings between evident SCCs and benign hyperkeratotic lesions in the same patient with RDEB. We report that MMP13 was found to be strongly positive in SCCs but negative in benign hyperkeratotic lesions. We found that there is an evident difference in the transitional area between SCCs and benign hyperkeratotic lesions. We propose that MMP13 may be a useful differentiating marker between SCC and benign hyperkeratotic lesions in RDEB.

The genetics of skin fragility

Genetic skin fragility manifests with diminished resistance of the skin and mucous membranes to external mechanical forces and with skin blistering, erosions, and painful wounds as clinical features. Skin fragility disorders, collectively called epidermolysis bullosa, are caused by mutations in 18 distinct genes that encode proteins involved in epidermal integrity and dermal-epidermal adhesion. The genetic spectrum, along with environmental and genetic modifiers, creates a large number of clinical phenotypes, spanning from minor localized lesions to severe generalized blistering, secondary skin cancer, or early demise resulting from extensive loss of the epidermis. Laboratory investigations of skin fragility have greatly augmented our understanding of genotype-phenotype correlations in epidermolysis bullosa and have also advanced skin biology in general. Current translational research concentrates on the development of biologically valid treatments with therapeutic genes, cells, proteins, or small-molecule compounds in preclinical settings or human pilot trials.

Hallopeau-Siemens dystrophic epidermolysis bullosa due to homozygous 5818delC mutation in the COL7A gene

Epidermolysis bullosa (EB) is a group of inherited mechanobullous skin disease. The dystrophic EB (DEB), one subtype of EB, is inherited in an autosomal dominant DEB or in an autosomal recessive (RDEB). DEB is caused by mutations in the COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils. Over 300 pathogenic mutations have been detected within COL7A in DEB. Patients with the Hallopeau-Siemens type (HS-RDEB), most severe form of DEB, frequently have premature termination codon (PTC) mutations on both alleles. PTC mutations on both alleles result in depleted mRNA and α1 helix, and failure to form the triple helix structure characteristic of type VII collagen. As patients with HS-RDEB usually have a pair of heterozygous PTC mutations, there have been rarely reported homozygous ones in HS-RDEB. We report the first case of HS-RDEB homozygous PTC mutations of 5818delC in both COL7A1 alleles. This case report suggests the positional effect of PTC mutations and vigilance against early infantile death in EB including HS-RDEB.

Inherited epidermolysis bullosa: Case report of finger localization

Inherited epidermolysis bullosa is a rare condition that often present at birth with skin blisters and erosions. They are associated with defective cohesion of the dermis and epidermis. There are 3 principal types: Simple, junctional and dystrophic. The severity of the condition is quite variable. The most severe forms are incompatible with life. The most common types in our country are the severe ones such as the Hallopeau -Siemens subtype. Hands and mucosal areas can develop synechia. We report here a case of dystrophic epidermolysis bullosa in a 27-year-old woman whose finger lesion was managed surgically. This treatment consisted of complete removal of constrictions and adhesions, accompanied by use of a Hueston flap and skin graft to repair the tissue deficit. The patient's clinical course required several repeat operations. This surgery allowed the possible total loss of hand function to be delayed but the inevitable progression of the illness made the treatment somewhat disappointing. Psychosocial implications are very significant in our setting.

Epidermolysis bullosa simplex associated with muscular dystrophy and cardiac involvement

We report a new clinical variant of epidermolysis bullosa simplex with muscular dystrophy (EBS-MD) that was associated with cardiac involvement. A 33-year-old patient had atrial fibrillation, pericardial effusion, and hypokinetic left ventricular cardiac walls. The muscle biopsy material revealed diffuse endomysial fibrosis and small atrophic muscle fibers with rounded contours. A positive desmin expression with abnormal localization in the subsarcolemmal groups was observed. We concluded that patients with EBS-MD should be investigated carefully when there are associated cardiac findings.

Oral health care for patients with epidermolysis bullosa--best clinical practice guidelines

OBJECTIVE

  To provide the users with information on the current best practices for managing the oral health care of people living with EB.

METHODS

  A systematic literature search, in which the main topic is dental care in patients with Epidermolysis Bullosa, was performed. Consulted sources, ranging from 1970 to 2010, included MEDLINE, EMBASE, CINAHL, The Cochrane Library, DARE, and the Cochrane controlled trials register (CENTRAL). In order to formulate the recommendations of the selected studies the SIGN system was used. The first draft was analysed and discussed by clinical experts, methodologists and patients representatives on a two days consensus meeting. The resulting document went through an external review process by a panel of experts, other health care professionals, patient representatives and lay reviewers. The final document was piloted in three different centres in United Kingdom, Czech Republic and Argentina.

RESULTS

  The guideline is composed of 93 recommendations divided into 3 main areas: 1) Oral Care--access issues, early referral, preventative strategies, management of microstomia, prescriptions and review appointments 2) Dental treatment: general treatment modifications, radiographs, restorations, endodontics, oral rehabilitation, periodontal treatment, oral surgery and orthodontics, and 3) Anaesthetic management of dental treatment.

CONCLUSIONS

  A preventive protocol is today's dental management approach of choice.

Inherited epidermolysis bullosa: an update and suggested dental care considerations

BACKGROUND

Epidermolysis bullosa (EB) is a skin disease characterized by epithelial fragility that leads to blistering and erosion of the skin and mucosae. The authors conducted a literature review to provide an update on oral manifestations and dental care of patients with EB. Literature Search. The authors reviewed the dental literature on EB in relation to clinical findings and provision of dental care. They searched textbooks and three databases: MEDLINE, Cochrane Library and Embase. The authors did not impose any date or publication status restrictions. They searched all databases up to August 2010.

RESULTS

The literature review revealed that four major groups and 32 subtypes of EB can be distinguished on the basis of the ultrastructural characteristics of skin cleavage, genetic mode of transmission and clinical phenotype. Oral manifestations differ in frequency and severity according to the disease subtype, but the most common are bullae, which leave painful ulcers on rupture, followed by scarring and tissue contraction. Although good oral health status is essential to maintaining oral function, dental treatment can induce new lesions and be hindered by the sequelae of existing lesions.

CLINICAL IMPLICATIONS

Dental treatment in patients with EB requires a multidisciplinary approach. Dental procedures must be minimally traumatic, and the effectiveness of treatment is determined mainly by the patient's general health, cooperation in the dental office and at home, oral hygiene and diet.

Two novel recessive mutations in KRT14 identified in a cohort of 21 Spanish families with epidermolysis bullosa simplex

BACKGROUND

Basal epidermolysis bullosa simplex (EBS) is a group of blistering genodermatoses mostly caused by mutations in the keratin genes, KRT5 and KRT14. Recessive mutations represent about 5% of all EBS mutations, being common and specific in populations with high consanguinity, where affected patients show severe phenotypes.

OBJECTIVES

To accomplish the first mutational analysis in patients of Spanish origin with EBS and to delineate a comprehensive genotype-phenotype correlation.

METHODS

Twenty-one EBS families were analysed. Immunofluorescence mapping at the dermoepidermal junction level was performed on skin biopsies from patients. Mutation screening of the entire coding sequences of KRT5 and KRT14 in genomic DNA was assessed by polymerase chain reaction and direct sequencing.

RESULTS

KRT5 or KRT14 causative mutations were identified in 18 of the 21 EBS families. A total of 14 different mutations were disclosed, of which 12 were dominant missense mutations and two truncating recessive mutations. Five of the 14 mutations were novel including three dominant in KRT5 (p.V186E, p.T321P and p.A428T) and two recessive in KRT14 (p.K116X and p.K250RfsX8). The two patients with EBS carrying homozygous recessive mutations were affected by severe phenotypes and belonged to consanguineous families. All five families with the EBS Dowling-Meara subtype carried recurrent mutations affecting the highly conserved ends of the α-helical rod domain of K5 and K14. The seven mutations associated with the localized EBS subtype were widely distributed along the KRT5 and KRT14 genes. Two families with mottled pigmentation carried the P25L mutation in KRT5, commonly associated with this subtype.

CONCLUSIONS

This study further confirms the genotype-phenotype correlation established for EBS in other ethnic groups, and is the first in a Mediterranean country (excluding Israel). This study adds two novel recessive mutations to the worldwide record to date, which includes a total of 14 mutations. As in previous reports, the recessive mutations resulted in a lack of keratin K14, giving rise to a generalized and severe presentation.

The international dystrophic epidermolysis bullosa patient registry: an online database of dystrophic epidermolysis bullosa patients and their COL7A1 mutations

Dystrophic epidermolysis bullosa (DEB) is a heritable blistering disorder that can be inherited autosomal dominantly (DDEB) or recessively (RDEB) and covers a group of several distinctive phenotypes. A large number of unique COL7A1 mutations have been shown to underlie DEB. Although general genotype-phenotype correlation rules have emerged, many exceptions to these rules exist, compromising disease diagnosing and genetic counseling. We therefore constructed the International DEB Patient Registry (http://www.deb-central.org), aimed at worldwide collection and sharing of phenotypic and genotypic information on DEB. As of May 2011, this MOLGENIS-based registry contains detailed information on 508 published and 71 unpublished patients and their 388 unique COL7A1 mutations, and includes all combinations of mutations. The current registry RDEB versus DDEB ratio of 4:1, if compared to prevalence figures, suggests underreporting of DDEB in the literature. Thirty-eight percent of mutations stored introduce a premature termination codon (PTC) and 43% an amino acid change. Submission wizards allow users to quickly and easily share novel information. This registry will be of great help in disease diagnosing and genetic counseling and will lead to novel insights, especially in the rare phenotypes of which there is often lack of understanding. Altogether, this registry will greatly benefit the DEB patients.

A Japanese-specific recurrent mutation and a novel splice site mutation in the LAMC2 gene identified in two Japanese families with Herlitz junctional epidermolysis bullosa

BACKGROUND

Herlitz junctional epidermolysis bullosa (H-JEB) is an extremely rare genodermatosis characterized by lethality owing to severe blister formation. We report two unrelated Japanese patients with H-JEB. Genetic analyses detected a single nonsense mutation on the LAMC2 gene in these two patients.

AIM

To identify the mutation involved and describe the first reported Japanese recurrent mutation in the LAMC2 gene.

METHODS

Direct sequencing was performed of DNA from either peripheral blood or fetal cells in amniotic fluid. Reverse transcriptase PCR was used to confirm that an aberrant transcript resulted from the splice site mutation. A haplotype analysis was performed to define the origin of the recurrent mutation.

RESULTS

Both patients had blisters and erosions on the trunk and limbs at birth, with nail dystrophy. Patient 1 died as a result of sepsis at 30 weeks of age, and patient 2 died as a result of disseminated intravascular coagulation at 20 weeks of age. Mutation analysis of the LAMC2 gene revealed that patient 1 was compound heterozygous for a nonsense mutation (p.Cys553X) and a novel splice site mutation (c.2868+1delG), and patient 2 was a homozygous for p.Cys553X. Prenatal diagnosis performed during a subsequent pregnancy in family 2 revealed that this second child was heterozygous for p.Cys553X, and was thus not affected. Haplotype analysis suggested that a p.Cys553X allele derived from the same origin had been independently inherited by these two unrelated families.

CONCLUSIONS

p.Cys553X in the LAMC2 gene may be a Japanese-specific recurrent mutation as a result of a founder effect, and it may therefore be useful for initial screening in the mutation analysis of H-JEB.

Inherited epidermolysis bullosa

Inherited epidermolysis bullosa (EB) encompasses a number of disorders characterized by recurrent blister formation as the result of structural fragility within the skin and selected other tissues. All types and subtypes of EB are rare; the overall incidence and prevalence of the disease within the United States is approximately 19 per one million live births and 8 per one million population, respectively. Clinical manifestations range widely, from localized blistering of the hands and feet to generalized blistering of the skin and oral cavity, and injury to many internal organs. Each EB subtype is known to arise from mutations within the genes encoding for several different proteins, each of which is intimately involved in the maintenance of keratinocyte structural stability or adhesion of the keratinocyte to the underlying dermis. EB is best diagnosed and subclassified by the collective findings obtained via detailed personal and family history, in concert with the results of immunofluorescence antigenic mapping, transmission electron microscopy, and in some cases, by DNA analysis. Optimal patient management requires a multidisciplinary approach, and revolves around the protection of susceptible tissues against trauma, use of sophisticated wound care dressings, aggressive nutritional support, and early medical or surgical interventions to correct whenever possible the extracutaneous complications. Prognosis varies considerably and is based on both EB subtype and the overall health of the patient.

Basement membrane changes in lichen planopilaris

BACKGROUND

Lichen planopilaris (LPP) is an inflammatory disease that affects the scalp and tends to produce cicatricial alopecia. The inflammatory process frequently results in the disruption of the basal cell of the external root sheath of the hair follicle.

OBJECTIVES

To investigate the alterations in the basement membrane zone (BMZ) in LPP by immunohistochemistry.

METHODS

Skin biopsies from six patients with LPP plus six normal controls were studied by immunohistochemistry with antibodies to the following BMZ components: cytokeratin 5, cytokeratin 14, BP230 (bullous pemphigoid), BP180, plectin, laminin 5, collagen IV and collagen VII.

RESULTS

The localization and staining of the hemidesmosome, laminin and collagen components were strikingly different in the inflamed follicular epithelium when compared to the uninvolved follicles or interfollicular epithelium in active LPP lesions. The hemidesmosome-associated complexes were weakly expressed and discontinuous in involved hair follicles. The expression of laminin-5, type IV collagen and type VII collagen was disrupted and not linear along the BMZ with finger-like projections of the staining protruding into the dermis. The expression of the intermediate filaments was normal.

CONCLUSION

These alterations in the BMZ in LPP may explain the abnormal healing at follicular level which leads to irreversible hair loss and scarring in this condition.

Dental and anaesthetic management of children with dystrophic epidermolysis bullosa

BACKGROUND

Epidermolysis bullosa (EB) is a genetic disease associated with fragility and bullous lesions of the skin and mucous membranes. There are various patterns of inheritance and histopathology. The disease is associated with systemic and oral manifestations, among which may be dental decay necessitating oral rehabilitation. General anaesthesia is frequently required for oral rehabilitation in children with dystrophic EB. Paediatric dentists should be aware of the implications of dystrophic EB for dental and anaesthetic management.

CASE REPORT

Two siblings with moderate to severe systemic and oral manifestations of dystrophic EB requiring extensive oral rehabilitation for rampant decay are described, including special anaesthetic techniques required for airway management and maintenance of skin integrity.

CONCLUSION

Dystrophic EB is a rare genetic disorder in which vesiculobullous lesions occur with erosions and scarring of cutaneous and extracutaneous surfaces in the oral cavity. Poor oral hygiene results from efforts to avoid mucosal trauma, resulting in decay. The comprehensive care of children with dystrophic EB impacts not only dental management but anaesthesia administration as well.

Doenças da pele em caprinos e ovinos no semi-árido brasileiro

Foi realizado um estudo das doenças de pele diagnosticadas em ovinos e caprinos, no semi-árido dos Estados da Paraíba, Pernambuco e Rio Grande do Norte. De janeiro de 2000 a novembro de 2006 foram registrados no Hospital Veterinário da Universidade Federal de Campina Grande, em Patos, Paraíba, 656 diagnósticos em caprinos e 324 em ovinos, além do estudo de espécimes de necropsia ou biópsia da pele de 31 em caprinos e 45 em ovinos enviados para exame histológico. Dos casos atendidos 80 (8,16%) apresentavam alterações na pele, destes 35 ocorreram em caprinos (5,33% do total de casos diagnosticados nesta espécie) e 45 em ovinos (13,88% dos casos diagnosticados nesta espécie). Das doenças de pele, a mais freqüente foi a miíase (10 casos em caprinos e 7 em ovinos) seguida do ectima contagioso (8 casos em caprinos e 2 em ovinos), carcinoma epidermoide (4 casos em caprinos e 5 em ovinos), dermatofilose (8 casos em ovinos), dermatite alérgica (1 caso em ovino e 1 em caprino). Além disso, foram diagnosticados dois casos de pitiose em ovinos, dois casos de epidermólise bolhosa em caprinos, um caso de intoxicação por Brachiaria brizantha (fotossensibilização) e outro de intoxicação por Leucaena leucocephala (alopecia) em ovinos e um caso de papilomatose, um de pênfigo foliáceo, um de prototecose e um de rabdomiossarcoma em caprinos. Em 4 casos em ovinos e 19 em caprinos não foi realizado diagnóstico etiológico da doença. A informação gerada sobre a ocorrência e epidemiologia das doenças de pele permite estabelecer medidas adequadas de controle.

Epidermolysis bullosa and the risk of life-threatening cancers: the National EB Registry experience, 1986-2006

BACKGROUND

Case series have demonstrated that potentially lethal cutaneous squamous cell carcinomas arise in patients with recessive dystrophic epidermolysis bullosa (RDEB), although the magnitude of this risk is undefined.

METHODS

Systematic case finding and data collection were performed throughout the continental United States (1986-2002) by the National EB Registry on 3280 EB patients to determine cumulative and conditional risks for squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and malignant melanoma (MM) within each major EB subtype, as well as the cumulative risk of death from each tumor. Study design was cross-sectional, with a nested randomly sampled longitudinal subcohort (N = 450).

RESULTS

SCCs arose primarily in RDEB, especially the Hallopeau-Siemens subtype (RDEB-HS), first beginning in adolescence. Less frequently, SCCs occurred in junctional EB (JEB). Cumulative risks rose steeply in RDEB-HS, from 7.5% by age 20 to 67.8%, 80.2%, and 90.1% by ages 35, 45, and 55, respectively. In Herlitz JEB, the risk was 18.2% by age 25. SCC deaths occurred only in RDEB, with cumulative risks in RDEB-HS of 38.7%, 70.0%, and 78.7% by ages 35, 45, and 55, respectively. MM arose in RDEB-HS, with a cumulative risk of 2.5% by age 12. BCCs arose almost exclusively in the most severe EB simplex subtype (Dowling-Meara) (cumulative risk = 43.6% by age 55).

LIMITATIONS

Mutational analyses were performed on only a minority of enrollees in the National EB Registry, preventing evaluation of the possible influence of specific genotypes on the risk of developing or dying from cutaneous SCCs.

CONCLUSIONS

SCC is the most serious complication of EB within adults, especially those with RDEB-HS. By mid-adulthood, nearly all will have had at least one SCC, and nearly 80% will have died of metastatic SCC despite aggressive surgical resection. When compared with SCCs arising within the normal population, the remarkably high risk of occurrence of and then death from SCCs among RDEB patients suggests likely differences in pathogenesis. Additional studies of EB-derived tumors and SCC cell lines may not only provide new insights into the mechanisms of carcinogenesis but also means whereby these particular tumors may be prevented or more effectively treated.

The risk of cardiomyopathy in inherited epidermolysis bullosa

BACKGROUND

Case reports have suggested that cardiomyopathy may be a complication of recessive dystrophic epidermolysis bullosa (RDEB).

OBJECTIVE

To determine the risk of congestive heart failure (CHF) or cardiomyopathy in each major EB subtype.

METHODS

These data represent systematic case findings and data collection performed throughout the continental United States from 1986 through 2002, by the National Epidermolysis Bullosa Registry. Study design is cross-sectional (n = 3280) with a nested randomly sampled longitudinal subcohort (n = 450). Frequencies of CHF and cardiomyopathy were determined by patient self-reporting, medical histories and review of medical records. In those who died, death certificates were reviewed and histories obtained from surviving family. Cumulative risks were stratified by cause and EB subtype.

RESULTS

Cardiomyopathy was reported as early as within the first year of life. In patients having no other known risk factors for CHF or cardiomyopathy, the highest risk of cardiomyopathy was seen among patients with Hallopeau-Siemens RDEB (RDEB-HS), with a cumulative risk of 4.51% on or after age 20 years. The cumulative risk of cardiomyopathy was only 1.14% and 0.40% in non-Herlitz junctional EB (JEB) and non-Hallopeau-Siemens RDEB, respectively, and was not observed in any other EB subtype. When patients with coexistent chronic renal failure were included, the cumulative risk for RDEB-HS rose to 18.86% by age 35 years. About 30% of our patients affected with RDEB-HS died of CHF or cardiomyopathy, even those with no other known risk factors.

CONCLUSIONS

CHF and cardiomyopathy are uncommon complications in both major RDEB subtypes and non-Herlitz JEB, and may be fatal.

Surgical treatment of pseudosyndactyly of children with epidermolysis bullosa: a case report

Recessive dystrophic epidermolysis bullosa (RDEB) is an uncommon and severe disorder characterised by trauma-induced blisters, intractable skin ulcers, scarring, milia, and nail dystrophy. We report the good result of both surgical release of fingers allowing spontaneous epithelisation without skin grafting and post-operative meticulous skin care without splinting, followed-up for one year.

Gastrointestinal complications of inherited epidermolysis bullosa: cumulative experience of the National Epidermolysis Bullosa Registry

BACKGROUND

Portions of the gastrointestinal (GI) tract may be severely involved in patients with inherited epidermolysis bullosa (EB). Evidence-based data are lacking as to the frequency and time of onset of these complications.

PATIENTS AND METHODS

Cross-sectional and longitudinal data were analyzed on 3,280 and 450 patients with EB, respectively, who were followed from 1986-2002 as part of the National EB Registry, an epidemiological study that attempted to identify, enroll, and collect data on every EB patient residing within the continental United States. Frequencies of abnormalities arising within the esophagus, stomach, small and large intestines, rectum, and anus were determined for each major EB subtype. Cumulative risks were similarly calculated for esophageal stenoses or strictures, and for severe growth retardation.

RESULTS

Esophageal strictures and growth retardation were commonly seen among the more severe EB subtypes, most notably Hallopeau-Siemens recessive dystrophic EB, and occurred as early as within the first year of life. EB subtype-specific differences were also observed in the frequency of occurrence of other GI complications.

DISCUSSION

A variety of GI complications arise in patients with inherited EB, varying across the major EB subtypes in their relative severity, frequency, and time of onset.

CONCLUSIONS

Data generated by the National EB Registry should provide a sound basis whereby evidence-based strategies can be implemented for more effective surveillance and treatment of specific GI complications.

Cause-specific risks of childhood death in inherited epidermolysis bullosa

OBJECTIVE

To determine the cause-specific risks of death in children with epidermolysis bullosa (EB).

STUDY DESIGN

Data were collected throughout the continental United States between 1986 and 2002 by the National EB Registry. The study design is cross-sectional (n = 3280), containing within it a nested randomly sampled longitudinal subcohort (n = 450).

RESULTS

The risk of death during infancy and childhood was greatest in junctional EB (JEB), with cumulative and conditional risks of 40% to 44.7% by age 1 in both JEB subtypes, rising to 61.8% in children with JEB, Herlitz subtype and 48.2% in those with JEB, non-Herlitz subtype (JEB-nH) by age 15. In decreasing order, sepsis, failure to thrive, and respiratory failure were the major causes of death in children with JEB, plateauing by age 2 to 6. A small minority of children with epidermolysis bullosa simplex, Dowling-Meara subtype was at risk for death by age 1 (cumulative risk, 2.8%), with sepsis and respiratory failure accounting for cumulative risks of 1.9% and 0.9%. Only a minority of children with recessive dystrophic epidermolysis bullosa, Hallopeau-Siemens subtype was at risk of death (cumulative risk = 8% by age 15). Renal failure also rarely accounted for death in children with JEB-nH.

CONCLUSIONS

Infants and children with inherited EB, particularly those with JEB, are at significant risk of death as a result of disease complications.

Tracheolaryngeal Complications of Inherited Epidermolysis Bullosa: Cumulative Experience of the National Epidermolysis Bullosa Registry

OBJECTIVES/HYPOTHESIS

To accurately determine the frequency with which complications arise in the ears, noses, and throats of patients with inherited epidermolysis bullosa (EB) as well as the cumulative risk of tracheolaryngeal stenosis or stricture.

STUDY DESIGN

Cross-sectional study (3,280 patients) with a nested, randomly sampled longitudinal subcohort (n=450), representing data collection, stratified by major EB subtype, of the National EB Registry, an epidemiologic project focused on enrolling all EB patients within the continental United States from 1986 to 2002, to permit generalization of findings to the entire American EB population.

METHODS

Systematic epidemiologic case finding and data collection were performed throughout the continental United States, followed by subclassification of patients by EB subtype. ENT complications were quantified via contingency tables (as frequencies) and lifetable analyses. Frequencies of surgical procedures were also determined.

RESULTS

The most important clinical ENT complication in inherited EB was tracheolaryngeal stenosis or stricture, arising during early childhood and primarily within infants and children with junctional EB (JEB) (cumulative risk of 39.8% and 12.8% in Herlitz and non-Herlitz JEB, respectively, by ages 6 and 9). Other uncommon complications included chronic otitis media, chronic otitis externa, and hearing loss.

CONCLUSIONS

Given the potential risk for sudden airway occlusion and death, meticulous surveillance by a pediatric otolaryngologist is a critical part of the overall management of infants and children with EB, especially those with JEB and two rare subtypes of generalized EB simplex. Elective tracheostomy should be considered in EB infants and children with evidence of airway embarrassment.

Amnia for intractable skin ulcers with recessive dystrophic epidermolysis bullosa: report of three cases

Recessive dystrophic epidermolysis bullosa (RDEB) is a disease characterized by recurrent blistering and chronic ulceration of the skin. In these patients, recurrent blisters frequently result in intractable skin ulcers due to impaired wound healing caused by mutations in the type VII collagen gene and malnutrition as well as by increased collagenase activity. To evaluate the efficacy of amnia for intractable ulcers in RDEB, we treated RDEB patients with amnia. The amniotic membrane was simply placed on the cleansed wound surface. The procedure was repeated once a week for up to 10 weeks. As a result, wound conditions improved remarkably after treatment with amnia for 2-10 weeks in all the patients, resulting in total re-epithelization of the ulcers. Amnia could be an effective therapy for intractable skin ulcers in RDEB patients, and should be considered as a re-emerging therapeutic option for the disease.