Hereditary epidermolysis bullosa

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

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

Practical Tips on Epidermolysis Bullosa for Caregivers: Part 2

The heritable condition epidermolysis bullosa (EB) is a rare but potentially devastating and life-threatening condition that is characterized primarily by cutaneous fragility, manifested when the dermis and epidermis fail to adhere properly. EB has no cure, and because of its rarity, few healthcare professionals have experience in treating it. Most families with an EB child are forced to rely on family caregiving which can be disruptive to family routines but, more importantly, place enormous time and emotional and financial burdens on the family. EB can be extremely painful, and families are often caught in the bind of trying to manage overwhelming financial burdens in an effort to help their children cope with excruciating pain. For many years, the nonprofit organization NoBabyBlisters.org has worked on five continents with families caring for EB children. Many of these families reside in under-developed nations with hot climates and limited healthcare resources. Over time, the healthcare professionals with NoBabyBlisters.org have worked with EB families both internationally and in the United States to develop a series of simple tips or "hacks" that may provide relief or great benefit to these children. The objective of this article is to share these field-tested tips with a wider audience. This is not a scientific study or a systematic review and is offered as a companion article to an earlier article on the same subject.

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

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

Severe hyponatremia in an infant with epidermolysis bullosa: a case report

Background

Epidermolysis bullosa is a rare inherited connective tissue disorder compromising cellular junctions. Blister formation is the first manifestation of epidermolysis bullosa. As cellular adhesion is affected, it can affect many organs. Due to compromised skin integrity, water loss and electrolyte imbalances are prevalent in these patients. However, hypernatremia is the usual observed sodium imbalance rather than hyponatremia.

Case presentation

The patient was a 48-day-old Iranian male infant born near term. He was diagnosed with epidermolysis bullosa at 1 month of age. The patient was brought to the pediatrics center with apnea and respiratory distress, and was intubated and admitted to the pediatric intensive care unit. His symptoms started 4 days before the admission with vomiting and poor feeding, and the patient later developed loss of consciousness. Vital signs revealed a pulse rate of 154 beats per minute, respiratory rate of 70 per minute, a temporal temperature of 36.5 °C, nondetectable blood pressure, and oxygen saturation of 96%. The patient was anuric at presentation and was rehydrated. Physical examination showed bolus eruptions all over the body but not in mucosal membranes. Important laboratory findings were white blood cell count of 41,000/mm³ with 68% neutrophils, hemoglobin of 10.8 g/dL, platelet count of 856,000/mm², negative C-reactive protein (CRP), blood sugar of 514 mg/dL, urea of 129 mg/dL, sodium of 98 mg/dL, corrected sodium of 105 mg/dL, potassium of 5.5 mg/dL, serum creatinine of 1.7 mg/dL, and serum procalcitonin of more than 75 ng/mL. Urine analysis revealed many red blood cells. Brain computed tomography demonstrated loss of differentiation between gray and white matter and effacement of cortical sulci suggesting severe cytotoxic edema.

We administered 3% hypertonic saline and corrected the plasma sodium levels, and provided the patient with multiple doses of mannitol as well as antibiotics due to the leukocytosis. Subsequently, after 3 days in pediatric intensive care unit, the symptoms of brain edema resolved, and after 4 days, he was weaned from the ventilator and extubated. Later he was discharged from the pediatric intensive care unit.

Conclusion

This study illustrates the possibility of severe hyponatremia in patients with epidermolysis bullosa to clinicians. Although uncommon, knowledge on such possibilities is vital due to the possible detrimental outcomes for patients.

Tie-Over Bolster Pressure Dressing Improves Outcomes of Skin Substitutes Xenografts on Athymic Mice

The efficacy of skin substitutes is established for the treatment of burn injuries, but its use is not limited to this condition. This technology has the potential to improve the treatment of various conditions by offering highly advanced and personalized treatments. In vivo studies are challenging but essential to move to clinical use in humans. Mice are the most widely used species in preclinical studies, but the main drawback of this model is the limited surface area of the graft in long-term transplantation studies caused by the displacement and the contraction of the graft. We improved the conventional surgical procedures by stabilizing the chamber covering the graft with intramuscular sutures and by adding a tie-over bolster dressing. The current study was therefore performed to compare outcomes of skin grafts between the conventional and optimized skin graft model. Human self-assembled skin substitutes (SASSs) were prepared and grafted to athymic mice either by the conventional method or by the new grafting method. Graft healing and complications were assessed using digital photographs on postoperative days 7, 14, and 21. Similar structure and organization were observed by histological staining. The new grafting method reduced medium and large displacement events by 1.26-fold and medium and large contraction events by 1.8-fold, leading to a 1.6-fold increase in graft surface area compared to skin substitutes grafted with the usual method. This innovation ensures better reproducibility and consistency of skin substitute transplants on mice.

Procedural analgesia with nitrous oxide at home for epidermolysis bullosa: A case report

RATIONALE

Epidermolysis bullosa (EB) is an inherited disease characterized by fragile skin with painful blistering, which requires lifelong skin and wound care. This case report describes the use of inhaled nitrous oxide (N2O) for procedural pain control at home during wound care in a young man with severe dystrophic EB. To our knowledge, only 1 case was reported by Ingelmo et al in 2017 regarding the use of N2O at home in a 4-year-old-child. To date, no such attempt has been made in adult patients.

PATIENT CONCERNS

Our patient was a 28-year-old man. Frequent blisters appear spontaneously, and are often preceded by erythema and itching. Patient required daily treatment daily consisting of lancing blisters with a needle and emptying them by compression.

DIAGNOSES

Severe recessive dystrophic EB diagnosed at the time of delivery.

INTERVENTIONS

Procedural pain control was managed by the auto-administration of an inhaled N2O and air gas mixture.

OUTCOMES

Conscious sedation with N2O leads to beneficial effects, such as reduction in dressing duration, acute procedural pain, local antibiotic needing, medication memory, anxiety, anticipatory pain, and fatigue after the dressing session.

LESSONS

N2O analgesia is safe and effective, resulting in a significant reduction in procedural pain and an improvement in the quality of life of patients and their caregivers.

Novel and very rare causative variants in the COL7A1 gene of Vietnamese patients with recessive dystrophic epidermolysis bullosa revealed by whole-exome sequencing

BACKGROUND

Dystrophic epidermolysis bullosa (DEB) is a rare inherited disorder characterized by skin fragility leading to trauma-induced subepidermal blisters and healing with scarring. DEB is caused by mutations in COL7A1, the gene encoding for type VII collagen (COLVII). The DEB inheritance trait is divided into dominant dystrophic epidermolysis bullosa (DDEB) and recessive dystrophic epidermolysis bullosa (RDEB).

METHODS

Whole-exome sequencing (WES) was performed for identifying mutations in six affected individuals of five Vietnamese families.

RESULTS

Three novel variants in total of eight variants were found in five families. The first novel variant causing glycine substitution (c.8279G>A, p.G2760E), the remaining two novel variants resulted in splice site affecting (c.4518+2delT and c.5821-2A>G). Functional analysis indicated that the splice site at c.4518+2delT resulted in a skipping of exon 43, leading to an in-frame deletion of 12 amino acids.

CONCLUSION

Our finding expands the spectrum of COL7A1 mutations and reports altered splicing at c.4518+2delT during the processing of the pre-mRNA. This study provides an additional scientific basis for diagnosis, genetic counseling, and prognosis purposes of EB patients.

Personalized Development of Antisense Oligonucleotides for Exon Skipping Restores Type XVII Collagen Expression in Junctional Epidermolysis Bullosa

Intermediate junctional epidermolysis bullosa caused by mutations in the COL17A1 gene is characterized by the frequent development of blisters and erosions on the skin and mucous membranes. The rarity of the disease and the heterogeneity of the underlying mutations renders therapy developments challenging. However, the high number of short in-frame exons facilitates the use of antisense oligonucleotides (AON) to restore collagen 17 (C17) expression by inducing exon skipping. In a personalized approach, we designed and tested three AONs in combination with a cationic liposomal carrier for their ability to induce skipping of COL17A1 exon 7 in 2D culture and in 3D skin equivalents. We show that AON-induced exon skipping excludes the targeted exon from pre-mRNA processing, which restores the reading frame, leading to the expression of a slightly truncated protein. Furthermore, the expression and correct deposition of C17 at the dermal-epidermal junction indicates its functionality. Thus, we assume AON-mediated exon skipping to be a promising tool for the treatment of junctional epidermolysis bullosa, particularly applicable in a personalized manner for rare genotypes.

Surgical Management of Hand Deformity in Epidermolysis Bullosa: Initial Experience and Technique

Epidermolysis bullosa describes a rare group of genetic mucocutaneous disorders characterized by excessive epithelial fragility resulting in mechanically induced blistering and abnormal wound healing.^1,2 Its prevalence and incidence are 8.2 and 19.6 per 1,000,000 live births, respectively.² Gene therapy, protein replacement, and cell therapy strategies have been investigated, but there is currently no cure.².

Epidermolysis Bullosa: A Case of Successful Total Hip Arthroplasty

Epidermolysis bullosa (EB) is a rare dermatological disease in which patients suffer from skin fragility and blisters. One of the major complications is the development of skin infections, which may preclude surgical intervention. We present a case of a 49-year-old female with a past medical history of EB, who presented to the emergency department (ED) with right groin pain of one-hour duration after falling on her right side. The patient underwent a successful open reduction and internal fixation for her right hip without complications. Over the course of three months after the procedure, she experienced worsening of the pain accompanied by skin necrosis and total collapse of the femoral head. Subsequent total hip replacement surgery was performed using a cementless (Zimmer, Warsaw, IN) prosthesis and fixated via cannulated screws. To decrease the risk of infection, IV cefazolin was given as a prophylactic antibiotic preoperatively. Vancomycin IV and imipenem/cilastatin IV were given for four days postoperatively. We made sure that our patient is experiencing the least possible pain by giving sufficient analgesics after the surgery. We used morphine, paracetamol, and gabapentin for pain control. For 25 days after the surgery, the patient did not complain of any pain. Upon follow-up, sutures were removed, and no surgical wound infection, rashes, or lacerations were noted. We encourage orthopedic surgeons dealing with patients suffering from dermatological conditions with fragile skin such as EB and decreased level of activity that requires total hip arthroplasty to proceed with the surgical intervention after considering adequate infection control to improve quality of life. 

Previously Unreported COL7A1 Mutation in a Somali Patient with Dystrophic Epidermolysis Bullosa

Epidermolysis bullosa (EB) encompasses a group of inheritable skin disorders characterized by various degrees of epithelial fragility that lead to cutaneous and mucosal blistering following negligible mechanical traumas. These disorders are clinically and genetically heterogeneous, ranging from mild skin involvement to severe disabling conditions with associated manifestations affecting the gastrointestinal and vesico-urinary tracts. EB may be classified into 4 main categories: simplex, junctional, dystrophic, and Kindler syndrome. Clinically, EB may present as syndromic or nonsyndromic forms. EB subtypes have mainly reported a number of mutations in the candidate COL7A1 gene encoding type VII collagen, a major stabilizing molecule of the dermoepidermal junction. Herein, we report a Somali girl with dystrophic EB who showed a previously unreported missense variant c.6797G>T in exon 86 in COL7A1.

Dental-craniofacial manifestation and treatment of rare diseases

Rare diseases are usually genetic, chronic and incurable disorders with a relatively low incidence. Developments in the diagnosis and management of rare diseases have been relatively slow due to a lack of sufficient profit motivation and market to attract research by companies. However, due to the attention of government and society as well as economic development, rare diseases have been gradually become an increasing concern. As several dental-craniofacial manifestations are associated with rare diseases, we summarize them in this study to help dentists and oral maxillofacial surgeons provide an early diagnosis and subsequent management for patients with these rare diseases.

[Mucosal manifestations of epidermolysis bullosa : Clinical presentation and management]

Mucosal lesions occur with different prevalence and severity in all subtypes of hereditary epidermolysis bullosa (EB), a group of rare genodermatoses. They are associated with increased morbidity and mortality, especially in severe junctional and dystrophic subtypes. Despite progress in clinical approaches to curative therapy, the management of these patients is still primarily symptom-oriented. Current recommendations mainly rely on expert opinion and experience from health care professionals of specialized centers, since the rarity of this disease largely limits the availability and feasibility of randomized controlled trials. Accurate preventive and supportive care measures, however, can significantly lessen symptoms, avoid/ameliorate complications, and enhance the quality of life of these patients.