Genetic Basis of Dominantly Inherited Transient Bullous Dermolysis of the Newborn: A Splice Site Mutation in the Type VII Collagen Gene

Transient bullous dermolysis of the newborn (TBDN) is a blistering disease evident at birth or shortly thereafter, but the blistering tendency decreases with advancing age. The tissue separation in TBDN is below the lamina densa, and electron microscopy has revealed abnormalities in anchoring fibrils. Immunofluorescence staining demonstrates intracellular accumulation of type VII collagen. In this study, we report a G-to-C transversion mutation in the last nucleotide of intron 35 of the type VII collagen gene (COL7A1) in a family with autosomal dominant TBDN in three generations. This nucleotide substitution abolishes the obligatory consensus 3'-acceptor splice site, predicting in-frame skipping of exon 36. Thus, TBDN in this family is caused by a mutation in COL7A1, and is therefore allelic with other variants of dominant dystrophic epidermolysis bullosa

Genetic Basis of Dominantly Inherited Transient Bullous Dermolysis of the Newborn: A Splice Site Mutation in the Type VII Collagen Gene

Transient bullous dermolysis of the newborn (TBDN) is a blistering disease evident at birth or shortly thereafter, but the blistering tendency decreases with advancing age. The tissue separation in TBDN is below the lamina densa, and electron microscopy has revealed abnormalities in anchoring fibrils. Immunofluorescence staining demonstrates intracellular accumulation of type VII collagen. In this study, we report a G-to-C transversion mutation in the last nucleotide of intron 35 of the type VII collagen gene (COL7A1) in a family with autosomal dominant TBDN in three generations. This nucleotide substitution abolishes the obligatory consensus 3'-acceptor splice site, predicting in-frame skipping of exon 36. Thus, TBDN in this family is caused by a mutation in COL7A1, and is therefore allelic with other variants of dominant dystrophic epidermolysis bullosa

Normal Molecular Weight of Type VII Collagen Produced by Recessive Dystrophic Epidermolysis Bullosa Keratinocytes

Studies of the recessive dystrophic form of epidermolysis bullosa (RDEB) have suggested that an abnormality in type VII collagen may be involved in the pathogenesis of this disorder. Indirect immunofluorescence studies have shown that the staining for type VII collagen along the dermal-epidermal junction is markedly reduced or absent in all but rare cases of severe, generalized RDEB. These findings imply that the genetic defect may involve type VII collagen but do not exclude the possibility that the alterations demonstrated are secondary, for example, to nonspecific proteolysis of type VII collagen. To evaluate the ability of cells of affected patients to produce type VII collagen, we cultured keratinocytes from a severely affected patient and immunoprecipitated type VII collagen from the cells. Keratinocytes were metabolically labelled with 35S-methionine, and solubilized cell extracts were reacted with antibody to type VII collagen. The results indicate that the patient's keratinocytes synthesize type VII collagen and that the MI of the protein synthesized does not differ from that of an unaffected control. Because cultured cells from a patient severely affected with recessive dystrophic epidermolysis bullosa produce type VII collagen, the genetic defect, at least in this patient, is unlikely to reside in a major truncation of the type VII collagen molecule

The Appearance of Four Basement Membrane Zone Antigens in Developing Human Fetal Skin

In order to study the ontogeny of various structural and antigenic components of the basement membrane zone of human skin, we have examined skin specimens from 20 aborted fetuses ranging in gestational ages from 6 to 25 weeks, utilizing light microscopy, transmission electron microscopy, and indirect immunofluorescence with antibodies to bullous pemphigoid antigen, laminin, type IV collagen, and to the antigen defined by KF-1 monoclonal antibody. Both laminin and type IV collagen were detectable as early as 6 weeks of gestational age. In contrast, bullous pemphigoid antigen and the antigen defined by KF- 1 antibody were not detectable before 10 weeks and 16 weeks, respectively. The appearance of bullous pemphigoid antigen correlated with stratification of the epidermis and the formation of hemidesmosomes and anchoring fibrils at the basement membrane zone. KF- 1 antigen is first expressed when the epidermis is further stratified, hemidesmosomes and anchoring fibrils are present in greater numbers and with increased frequency at the dermal-epidermal junction, and hair follicles have begun to bud downward from the basal layer of the epidermis. Our findings suggest an orderly sequence to the appearance of these basement membrane zone components within human skin

Lamina Densa Malformation Involved in Histogenesis of Primary Localized Cutaneous Amyloidosis

Skin lesions of lichenoid amyloidosis and macular amyloidosis were immunohistochemically investigated using five monoclonal antibodies against basement membrane zone (BMZ) components. A hemidesmosomal component did not contribute to amyloid deposits, but components of the lamina densa and anchoring fibrils were associated with amyloid deposits in the uppermost dermis. Immunoelectron microscopy revealed that these BMZ components were not only aggregated in the BMZ and dermis, but were also involved in the individual amyloid islets. The lamina densa was disrupted in the interface areas just above the amyloid deposits, where cytoplasm of the basal cells directly faced the aggregate of amyloid filaments. Aggregates of some BMZ components were continuous to the amyloid islets from the lamina densa area. These findings suggest that a lamina densa malformation is involved in amyloid production in the interface of the BMZ, and support the secretion theory rather than the fibrillar body theory of amyloidogenesis in these types of primary localized cutaneous amyloidosis

Genotype-phenotype correlation in Junctional Epidermolysis Bullosa:signposts to severity

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

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

Increased Frequency of HLA-DR2 in Patients with Autoantibodies to Epidermolysis Bullosa Acquisita Antigen: Evidence that the Expression of Autoimmunity to Type VII Collagen Is HLA Class II Allele Associated

Epidermolysis bullosa acquisita (EBA) is a chronic blistering disease characterized by circulating and tissue bound IgG auto-antibodies to the basement membrane zone (BMZ) of stratified squamous epithelium. Recent studies have shown that antibodies recognize epitopes present in the noncollagenous carboxyl-terminal domain of type VII collagen, a BMZ matrix protein. Antibodies with identical specificity also have been detected in patients with the rare blistering disease, bullous systemic lupus erythematosus (bullous SLE), suggesting EBA and bullous SLE are immunologically related diseases. In this study we determined the major histo-compatibility antigen types of 29 EBA patients and 6 patients with bullous SLE. Analysis of the results showed HLA-DR2 was significantly increased in both black EBA patients, P = 0.013 (corrected, RR = 4.8) and whit EBA patients, P = 0.0008 (corrected, RR = 13.1). Five of the six bullous SLE patients also were positive for the DR2 antigen, P = 0.009. These results show the expression of autoimmunity to type VII collagen is HLA class II allele associated and that EBA and bullous SLE are immunogentically related diseases

Garotas de loja, história social e teoria social [Shop Girls, Social History and Social Theory]

Shop workers, most of them women, have made up a significant proportion of Britain’s labour force since the 1850s but we still know relatively little about their history. This article argues that there has been a systematic neglect of one of the largest sectors of female employment by historians and investigates why this might be. It suggests that this neglect is connected to framings of work that have overlooked the service sector as a whole as well as to a continuing unease with the consumer society’s transformation of social life. One element of that transformation was the rise of new forms of aesthetic, emotional and sexualised labour. Certain kinds of ‘shop girls’ embodied these in spectacular fashion. As a result, they became enduring icons of mass consumption, simultaneously dismissed as passive cultural dupes or punished as powerful agents of cultural destruction. This article interweaves the social history of everyday shop workers with shifting representations of the ‘shop girl’, from Victorian music hall parodies, through modernist social theory, to the bizarre bombing of the Biba boutique in London by the Angry Brigade on May Day 1971. It concludes that progressive historians have much to gain by reclaiming these workers and the service economy that they helped create

Identification and reconstruction of low-energy electrons in the ProtoDUNE-SP detector

Measurements of electrons from $\nu_e$ interactions are crucial for the Deep Underground Neutrino Experiment (DUNE) neutrino oscillation program, as well as searches for physics beyond the standard model, supernova neutrino detection, and solar neutrino measurements. This article describes the selection and reconstruction of low-energy (Michel) electrons in the ProtoDUNE-SP detector. ProtoDUNE-SP is one of the prototypes for the DUNE far detector, built and operated at CERN as a charged particle test beam experiment. A sample of low-energy electrons produced by the decay of cosmic muons is selected with a purity of 95%. This sample is used to calibrate the low-energy electron energy scale with two techniques. An electron energy calibration based on a cosmic ray muon sample uses calibration constants derived from measured and simulated cosmic ray muon events. Another calibration technique makes use of the theoretically well-understood Michel electron energy spectrum to convert reconstructed charge to electron energy. In addition, the effects of detector response to low-energy electron energy scale and its resolution including readout electronics threshold effects are quantified. Finally, the relation between the theoretical and reconstructed low-energy electron energy spectrum is derived and the energy resolution is characterized. The low-energy electron selection presented here accounts for about 75% of the total electron deposited energy. After the addition of lost energy using a Monte Carlo simulation, the energy resolution improves from about 40% to 25% at 50~MeV. These results are used to validate the expected capabilities of the DUNE far detector to reconstruct low-energy electrons.Comment: 19 pages, 10 figure