Genotype-phenotype correlations on epidermolysis bullosa with congenital absence of skin: A comprehensive review.

Congenital absence of skin (CAS) is a clinical sign associated with the main types of epidermolysis bullosa (EB). Very few studies have investigated the genetic background that may influence the occurrence of this condition. Our objective was to investigate genotype-phenotype correlations on EB with CAS through a literature revision on the pathogenic variants previously reported. A total of 171 cases (49 EB simplex, EBS; 23 junctional EB, JEB; and 99 dystrophic EB, DEB), associated with 132 pathogenic variants in eight genes, were included in the genotype-phenotype analysis. In EBS, CAS showed to be a recurrent clinical sign in EBS with pyloric atresia (PA) and EBS associated with kelch-like protein 24; CAS was also described in patients with keratins 5/14 alterations, particularly involving severe phenotypes. In JEB, this is a common clinical sign in JEB with PA associated with premature termination codon variants and/or amino acid substitutions located in the extracellular domain of integrin α6ß4 genes. In DEB with CAS, missense variants occurring close to non-collagenous interruptions of the triple-helix domain of collagen VII appear to influence this condition. This study is the largest review of patients with EB and CAS and expands the spectrum of known variants on this phenomenon.

Self-improving dystrophic epidermolysis bullosa: First report of clinical, molecular, and genetic characterization of five patients from Southeast Asia.

Self-improving dystrophic epidermolysis bullosa is a rare subtype of dystrophic epidermolysis bullosa (DEB) characterized by significant improvement in skin fragility within the first few years of life. Genetic inheritance has previously been reported as autosomal dominant or recessive with both forms harboring mutations in COL7A1. To date, there have been no reports of this rare clinical entity from various Southeast Asian ethnicities. Here, we describe the clinical and molecular features of five patients from the Southeast Asia region who presented with predominantly acral-distributed blisters and erosions in the first few days of life. Blistering resolved over several months, without appearance of new blisters. By immunofluorescence, intraepidermal retention of Type VII collagen was observed in all patient skin biopsies when investigated with antibody staining. Genetic analysis of four patients revealed pathogenic variants in COL7A1 which have not been previously reported. The clinical diagnosis in these rare patients is confirmed with molecular histology and genetic characterization.

Successful forearm prosthesis fitting in a patient with epidermolysis bullosa dystrophica: Case report.

BACKGROUND: Epidermolysis bullosa dystrophica is a rare dermatological disease characterized by extreme skin fragility and elevated risk of developing a squamous cell carcinoma. In some cases, amputation of a limb is necessary. Case description and methods: A 37-year-old man with recessive, severe generalized epidermolysis bullosa dystrophica developed a squamous cell carcinoma on the right forearm requiring a below-elbow amputation. Preoperative advice concerning indication and level of amputation was given. Due to potential skin problems, a conventional prosthesis was not feasible. Findings and outcomes: A custom-designed adaptive prosthesis with an upper arm cuff was trialed and was well tolerated. Multiple working tools, attached with a rotation and inclination system, allowed independence and return to work. CONCLUSION: Despite multiple potential skin problems of the stump, the patient was successfully fitted with a custom-designed adaptive prosthesis. Preparation for this fitting was done by a comprehensive multidisciplinary patient-centered approach. Clinical relevance Despite severe skin fragility, a patient with epidermolysis bullosa dystrophica was successfully fitted with a custom-designed adaptive upper limb prosthesis allowing good functional outcome. This required a multidisciplinary and patient-centered approach.

Recessive dystrophic epidermolysis bullosa results in painful small fibre neuropathy.

Small fibres in the skin are vulnerable to damage in metabolic or toxic conditions such as diabetes mellitus or chemotherapy resulting in small fibre neuropathy and associated neuropathic pain. Whether injury to the most distal portion of sensory small fibres due to a primary dermatological disorder can cause neuropathic pain is still unclear. Recessive dystrophic epidermolysis bullosa (RDEB) is a rare condition in which mutations of proteins of the dermo-epidermal junction lead to cycles of blistering followed by regeneration of the skin. Damage is exclusive to the skin and mucous membranes, with no known direct compromise of the nervous system. It is increasingly recognized that most RDEB patients experience daily pain, the aetiology of which is unclear but may include inflammation (in the wounds), musculoskeletal (due to atrophy and retraction scars limiting movement) or neuropathic pain. In this study we investigated the incidence of neuropathic pain and examined the presence of nerve dysfunction in RDEB patients. Around three quarters of patients presented with pain of neuropathic characteristics, which had a length-dependent distribution. Quantitative sensory testing of the foot revealed striking impairments in thermal detection thresholds combined with an increased mechanical pain sensitivity and wind up ratio (temporal summation of noxious mechanical stimuli). Nerve conduction studies showed normal large fibre sensory and motor nerve conduction; however, skin biopsy showed a significant decrease in intraepidermal nerve fibre density. Autonomic nervous system testing revealed no abnormalities in heart rate and blood pressure variability however the sympathetic skin response of the foot was impaired and sweat gland innervation was reduced. We conclude that chronic cutaneous injury can lead to injury and dysfunction of the most distal part of small sensory fibres in a length-dependent distribution resulting in disabling neuropathic pain. These findings also support the use of neuropathic pain screening tools in these patients and treatment algorithms designed to target neuropathic pain.

A case of congenital pyloric atresia with dystrophic epidermolysis bullosa.

Pyloric atresia with epidermolysis bullosa (EB) dystrophica is a rare entity that may not be immediately recognized. We describe the fourth confirmed case of pyloric atresia associated with the dystrophic subtype of EB diagnosed by standard pathologic measures, and discuss the clinical disease features and recent advances in the pathophysiology.

Allogeneic blood and bone marrow cells for the treatment of severe epidermolysis bullosa: repair of the extracellular matrix.

Contrary to the prevailing professional opinion of the past few decades, recent experimental and clinical data support the fact that protein replacement therapy by allogeneic blood and marrow transplantation is not limited to freely diffusible molecules such as enzymes, but also large structural proteins such as collagens. A prime example is the cross-correction of type VII collagen deficiency in generalised severe recessive dystrophic epidermolysis bullosa, in which blood and marrow transplantation can attenuate the mucocutaneous manifestations of the disease and improve patients' quality of life. Although allogeneic blood and marrow transplantation can improve the integrity of the skin and mucous membranes, today's accomplishments are only the first steps on the long pathway to cure. Future strategies will be built on the lessons learned from these first transplant studies.

A reporter-based screen to identify potent 3' trans-splicing molecules for endogenous RNA repair.

In the treatment of genetic disorders, repairing defective pre-mRNAs by RNA trans-splicing has become an emerging alternative to conventional gene therapy. Previous studies have made clear that the design of the binding domains of the corrective RNA trans-splicing molecules (RTMs) is crucial for their optimal functionality. We established a reporter-based screening method that allows for selection of highly functional RTMs from a large pool of variants. The efficiency and functionality of the screen were validated in the COL7A1 gene, in which mutations are the cause of the skin disease dystrophic epidermolysis bullosa. Comparison of RTMs containing different binding domains hybridizing to COL7A1 intron 64/exon 65 revealed highly different trans-splicing efficiencies. Isolated RTMs were then adapted for endogenous trans-splicing in a recessive dystrophic epidermolysis bullosa (RDEB) keratinocyte cell line expressing reduced levels of COL7A1 mRNA. Our results confirm the applicability and relevance of prescreening reporter RTMs, as significant levels of endogenous COL7A1 mRNA repair were seen with RTMs identified as being highly efficient in our screening system.

Cell-based therapy for RDEB: how does it work?

No effective or specific treatment is currently available for recessive dystrophic epidermolysis bullosa (RDEB), a severe heritable blistering disorder caused by mutations in the type VII collagen gene (COL7A1). Recent studies have suggested that delivery of allogeneic fibroblasts to the skin of patients with RDEB may be beneficial in improving skin adhesion and increasing type VII collagen deposition at the dermal-epidermal junction. In this issue, Nagy et al. explore mechanisms of fibroblast therapy in a patient with RDEB displaying reduced type VII collagen protein expression at the dermal-epidermal junction. The results suggest that allogeneic fibroblast injection elicits expression of cytokines, including heparin binding-EGF-like growth factor (HB-EGF), that upregulate the expression of a patient-specific COL7A1 allele. Thus, fibroblast therapy may provide a novel way to improve skin therapy in a select subgroup of patients with this currently intractable disease.

Restrictions in oral functions caused by oral manifestations of epidermolysis bullosa.

Several forms of epidermolysis bullosa (EB) present oral manifestations. Blistering of the (peri)oral mucosa affects the opening of the mouth, the mobility of the tongue and lips, thereby restricting oral functions. We describe the prevalence and characteristics of oral manifestations of EB in relation to loss of oral functions in a cross-sectional study of different types of EB patients using standardized measurement techniques. Twenty-two patients were included. The mobility of the mandible, lips and tongue was measured, the mandibular function impairment questionnaire (MFIQ) was filled out and additional questions regarding hindrance of EB during oral hygiene and intelligibility of speech (being understood) were asked in structured interviews. The median age was 11.8 yrs. Mobility of the mandible, tongue and lip was restricted, oral hygiene procedures were hindered in most patients. A data comparison was made between the recessive dystrophic EB (RDEB) and junctional EB (JEB) groups. Mandibular function was impaired in both groups but more severely in the RDEB-population. Intelligibility in both groups was almost unaffected. Restrictions in mobility of the mouth, tongue and lips are frequently present in EB patients. These are most severe in the RDEB group and support the clinical relevance of optimizing symptomatic treatment.

A case of dystrophic epidermolysis bullosa improved with etanercept for concomitant psoriatic arthritis.

Epidermolysis bullosa is a group of inherited, chronic, non-inflammatory skin disorders, and dystrophic epidermolysis bullosa (DEB) is one of the most severe variants. The role of tumour necrosis factor alpha (TNFalpha) has not been reported in the pathogenesis of DEB. A DEB case is reported that appears to have responded well to the TNFalpha inhibitor etanercept given for the treatment of concomitant psoriatic arthritis. A progressive improvement in DEB was apparent over the first 3 months of treatment and persistent good control of DEB was noted over 3 years of therapy. A correlation between DEB improvement and etanercept has not been made, but the case may provide insight into the causal mechanisms of DEB.

A hypomorphic mouse model of dystrophic epidermolysis bullosa reveals mechanisms of disease and response to fibroblast therapy.

Dystrophic epidermolysis bullosa (DEB) is a severe skin fragility disorder associated with trauma-induced blistering, progressive soft tissue scarring, and increased risk of skin cancer. DEB is caused by mutations in type VII collagen. In this study, we describe the generation of a collagen VII hypomorphic mouse that serves as an immunocompetent animal model for DEB. These mice expressed collagen VII at about 10% of normal levels, and their phenotype closely resembled characteristics of severe human DEB, including mucocutaneous blistering, nail dystrophy, and mitten deformities of the extremities. The oral blistering experienced by these mice resulted in growth retardation, and repeated blistering led to excessive induction of tissue repair, causing TGF-beta1-mediated contractile fibrosis generated by myofibroblasts and pseudosyndactyly in the extremities. Intradermal injection of WT fibroblasts resulted in neodeposition of collagen VII and functional restoration of the dermal-epidermal junction. Treated areas were also resistant to induced frictional stress. In contrast, untreated areas of the same mouse showed dermal-epidermal separation following induced stress. These data demonstrate that fibroblast-based treatment can be used to treat DEB in a mouse model and suggest that this approach may be effective in the development of clinical therapeutic regimens for patients with DEB.

Reduced expression of insulin-like growth factor-binding protein-3 (IGFBP-3) in Squamous cell carcinoma complicating recessive dystrophic epidermolysis bullosa.

Squamous cell carcinoma (SCC) is a common complication in individuals with recessive dystrophic epidermolysis bullosa (RDEB). For the severe Hallopeau-Siemens subtype, the mortality rate from SCC is over 55% by the age of 40 y. Currently, little is known about the molecular pathology or cell biology of SCC in RDEB. In this study, we compared gene expression in RDEB SCC (n=3) and non-EB SCC (n=3) with corresponding RDEB and non-EB peri-tumoral skin, with microarray analysis using DermArray membranes as well as semi-quantitative and real-time RT-PCR. Both tumor sets showed downregulation of epidermal differentiation markers (e.g., profilaggrin, keratins 1 and 10) as well as certain pro-apoptotic genes (e.g., death-associated kinase-3 or ZIP kinase). Likewise, in both groups there was upregulation of matrix metalloproteinase 1 and laminin 5 in the tumors. But we found that the expression of insulin-like growth factor-binding protein-3 (IGFBP-3) was lower (mean of 5.8-fold) in RDEB SCC compared with non-EB SCC. These data were verified by immunohistochemistry. IGFBP-3 has an important role in cancer cell apoptosis mediated via the nuclear retinoid X receptor alpha (RXRalpha). Reduced expression of IGFBP-3 in RDEB SCC may provide a partial explanation for the aggressive behavior and poor prognosis of these tumors in this genodermatosis.

Twelve hour anaesthesia in a patient with epidermolysis bullosa.

Epidermolysis bullosa (EB), an inherited disorder presents clinically with recurrent cutaneous blister formation with possible involvement of mucous membranes and other organs. The sequelae of this disease pose multiple challenges to the anaesthetist and operating room team. Recent literature describes several anaesthetic techniques for the short surgical procedures this patient population may undergo. We describe the anaesthetic technique employed in a 28-yr-old women with recessive dystrophic epidermolysis bullosa who underwent 12 hr reconstructive surgery followed by a review of the literature that includes a recent description of the possible association of EB with at least two distinct neuromuscular diseases. A detailed description of airway and skin management is described in addition to preoperative concerns. We conclude that a prolonged operative procedure can be undertaken successfully in this population with minimal sequelae involving skin integrity and airway management.

Epidermólisis ampollosa distrófica recesiva generalizada (Síndrome de Hallopeau-Siemens): comunicación de un caso / Recessive epidermolysis dystrophic bullous (Hallopeau Siemens Syndrome): a case report

Se reporta el caso de una paciente de 40 días de nacida con un epidermólisis bulosa distrófica recesiva generalizada (Sindrome de Hallopeau-Siemens).