Molekularne podłoże keratynopatii

Keratin disorders are a group of rare bullous skin diseases. They are caused by mutations in genes encoding keratins – the main structural proteins of intermediate filament cytoskeleton of epithelial cells and also one of the major components of hair and nails. Different pairs of keratins are the expressed depending on the skin layer, thus variability in the course of keratinopathies is observed. This disorders are inherited in autosomal dominant pattern mostly. Mutations occur in different regions of the keratin genes. In most of these diseases correlation between the location of mutations, and the severity of clinical symptoms can be observed. The most common keratin disorder is epidermolysis bullosa simplex (EBS), which is caused by mutations in KRT5 and KRT14. These genes are expressed in basal layer of epidermal cells. Depending on the effect of the molecular defect in the protein, EB simplex can phenotype of EBS may be highly different - from mild and localized forms, to severe and generalized. Another disease from this group is epidermolytic ichthyosis, which is caused by mutations in KRT1 and KRT10, expressed in epidermal suprabasal cell layer. This paper contains an overview of selected keratin disorders in terms of their molecular pathology. Beside those mentioned above, ichthyosis bullosa of Siemiens, pachyonychia congenita, and Dowling-Degos disease are also described.     

Severe mucous membrane involvement in epidermolysis bullosa simplex with muscular dystrophy due to a novel plectin gene mutation

Epidermolysis bullosa simplex with muscular dystrophy (OMIM 226670) is an autosomal recessive disorder caused by mutations of the human plectin gene on chromosome 8q24. Here, we report a 3-year-old girl, offspring of a consanguineous Lebanese family, who presented with skin blistering and recurrent episodes of severe respiratory distress necessitating tracheotomy at the age of 2 years. Repeated examination did not provide any evidence of muscle involvement. Indirect immunofluorescence analysis of a diagnostic skin biopsy with four different domain specific plectin antibodies showed a complete absence of plectin staining. Mutation analysis revealed a novel homozygous single guanine insertion mutation (5588insG/5588insG) residing in the N-terminal part of exon 31 of the plectin gene. Conclusion: the complete lack of protein expression, which may be attributed to a nonsense-mediated plectin mRNA decay, is likely to cause muscular dystrophy and other multisystem involvement later in life.Abbreviations EB epidermolysis bullosa - EBS epidermolysis bullosa simplex - EBS-MD epidermolysis bullosa simplex with muscular dystrophy - PLEC1 plectin gene     

Molecular diagnostics facilitate distinction between lethal and non-lethal subtypes of junctional epidermolysis bullosa: a case report and review of the literature

The term epidermolysis bullosa (EB) encompasses a heterogeneous group of genodermatoses, characterised by fragility and blistering of the skin, often associated with extracutaneous manifestations. The clinical picture comprises severe subtypes with lethal outcome in the first years of life as well as milder subtypes with localised blistering or minimal symptoms confined exclusively to nail or teeth abnormalities. We present the case of a male infant, who was born with a few bullae and rapidly developed extensive blistering of the skin. The disease was complicated by painful erosions of the oral mucosa, refused ingestion, and recurrent infections. The child died at the age of 4 months because of cardiac failure due to severe sepsis. Antigen mapping of a skin biopsy showed a split within the lamina lucida of the epidermal basement membrane zone and junctional epidermolysis bullosa (JEB) was diagnosed within the first 3 weeks of life. Markedly reduced staining for laminin 5 indicated the Herlitz type of JEB (OMIM 226700), which could be confirmed by mutation analysis in the LAMB3 gene, showing homozygous nonsense mutations. CONCLUSION: early antigen mapping using antibodies against the proteins affected in epidermolysis bullosa, is a useful tool providing early mutation analysis and valuable prognostic information needed for adequate therapeutic strategies. The recently published literature on current diagnostic procedures and the revised classification system for inherited epidermolysis bullosa aim towards a better understanding of the disease.     

Pediatric patient with end‐stage kidney disease secondary to Eagle‐Barrett syndrome and metastatic unresectable hepatoblastoma treated successfully with chemotherapy and liver‐kidney transplant

HBL is the most common malignant liver neoplasm in children. The etiology of HBL is largely unknown but there are certain syndromes, such as Beckwith‐Wiedemann syndrome, that have been clearly associated with an increased incidence of this malignancy. EBS, also known as prune belly syndrome, is a congenital anomaly characterized by lax abdominal musculature, bilateral cryptorchidism requiring, in some cases, hemodialysis due to significant kidney and urinary tract dysfunctions. Despite an improvement on the survival rates of patients with advanced‐stage HBL, the presence of concomitant end‐stage renal disease that occurs in patients with EBS constitutes a therapeutic challenge for the clinician not only due to the use of nephrotoxic chemotherapy but also due to the potential need for multi‐organ transplant. We report case of a 2‐year‐old male patient with EBS diagnosed with stage IV, metastatic HBL successfully treated with multi‐agent chemotherapy while on dialysis whom then underwent a simultaneous liver‐kidney transplant followed by adjuvant chemotherapy. Ultimately, the patient achieved cancer remission with normalization of his renal function. Our report emphasizes that patients with HBL in the setting of EBS will not only require careful kidney function monitoring while receiving chemotherapy, but they might also need to undergo multi‐organ transplantation in order to achieve adequate cancer control and also normalization of their kidney function. Awareness of this unusual association calls for further investigation to potentially establish a genetic association between these two disease processes.     

Successful Hypothermia Treatment of Hypoxic-Ischemic Encephalopathy in a Neonate with Epidermolysis Bullosa

Despite advances in the neonatal care, hypoxic ischemic encephalopathy in late preterm and term infants remains an important cause of morbidity and mortality. There is lack of data on the application of therapeutic hypothermia in the existence of severe skin lesions. Epidermolysis bullosa is a rare group of inherited conditions which causes blisters in skin and mucosal membranes. In this report, the authors describe a successful whole-body hypothermia treatment of severe hypoxic ischemic encephalopathy in a term newborn with dystrophic epidermolysis bullosa. They observed that therapeutic hypothermia may also be given in newborns with dystrophic epidermolysis bullosa without any complications.     

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.     

2Q型肢带型肌营养不良症的研究进展

肢带型肌营养不良症（LGMD）包括一组肌无力主要呈近端分布的肌营养不良，目前已确定一些与此疾病相关的基因。2Q型肢带型肌营养不良症（LGMD2Q）是肢带型肌营养不良症中的一个亚型，与PLEC基因突变有关。PLEC基因突变表型主要包括大疱性表皮松解症伴迟发型肌营养不良和大疱性表皮松解症伴其他病变，而无皮肤病变的LGMD2Q表型目前报道罕见。该文通过对LGMD2Q的致病基因PLEC及临床表现进行综述，以加深对LGMD2Q的致病基因和表型的认识。     

Lethal cardiomyopathy in epidermolysis bullosa associated with amitriptyline

There are previous reports of dilated cardiomyopathy (DCM) in recessive dystrophic epidermolysis bullosa (RDEB), a debilitating blistering skin disorder. The pathogenesis of DCM in RDEB remains uncertain, although dietary deficiency of selenium and carnitine have been implicated. A 6 year old girl with RDEB who died of DCM is reported; attention is drawn to the possible role of two potentially cardiotoxic drugs, amitriptyline and cisapride.     

Corneal ulcer in a young child with autosomal recessive epidermolysis bullosa

Ocular manifestations of epidermolysis bullosa typically occur in patients with severe skin findings and are more likely with increasing age. An 18-month-old boy with relatively mild dermatologic epidermolysis bullosa developed corneal ulceration and scarring.     

Lethal cardiomyopathy in epidermolysis bullosa associated with amitriptyline.

There are previous reports of dilated cardiomyopathy (DCM) in recessive dystrophic epidermolysis bullosa (RDEB), a debilitating blistering skin disorder. The pathogenesis of DCM in RDEB remains uncertain, although dietary deficiency of selenium and carnitine have been implicated. A 6 year old girl with RDEB who died of DCM is reported; attention is drawn to the possible role of two potentially cardiotoxic drugs, amitriptyline and cisapride.     

Junctional epidermolysis bullosa. Treatment with phenytoin

Junctional epidermolysis bullosa (EB) is a rare, heritable, blistering disease of the skin characterized by presence of bullae at birth, lack of scarring of the lesions, and early death. To date there has been no effective treatment for the disease. Phenytoin, which decreases collagenase activity in human skin explants and fibroblast cultures, has been used successfully to treat patients with recessive dystrophic EB. We found a marked decrease in new blister formation in one child with junctional EB during phenytoin therapy.     

EPIDERMOLYSIS BULLOSA IN ASSOCIATION WITH APLASIA CUTIS CONGENITA AND PYLORIC ATRESIA

ABSTRACT. A female infant born to a mother who had an elevated serum alpha-fetoprotein during early pregnancy, presented a combinstion of epidermolysis bullosa and aplasia cutis congenita. She developed evidence of upper gastrointestinal obstruction and died at the age of 43 hours. Post-mortem examination showed the presence of pyloric atresia and electron microscopy of skin biopsies showed epidermolysis bullosa simplex. Examination of the placenta revealed a unique abnormality of the membranes, indicating the existence of two sacs. This case and the previously reported cases, which are reviewed, suggest an autosomal recessive inheritance. Serum alphafetoprotein estimation, ultrasonography and fetoscopy with skin biopsy are suggested as a means of pre-natal diagnosis in future pregnancies.     

Lethal junctional epidermolysis bullosa with normal expression of BM 600 and antro-pyloric atresia: A new variant of junctional epidermolysis bullosa?

A newborn girl is described with a lethal junctional epidermolysis bullosa (Herlitz form) (JEB) associated with a congenital localized absence of skin, and a pyloric atresia (PA). The post-mortem examination of the digestive tract showed a widespread cleavage betweeen the epithelium and the chorion. Immunohistological and electron microscopical examination showed a cleavage occurring through the lamina lucida of the digestive basement membrane, as for the skin blisters. Despite the lethal character of this form of JEB, the BM 600 glycoprotein was normally recognized at the dermo-epidermal junction by the monoclonal antibody GB3. This rare association of lethal JEB-PA-localized absence of skin, with a quite unusual GB3 positive immunophenotype could correspond to a new variant of JEB.     

Leukocytoclastic vasculitis in a child with epidermolysis bullosa simplex

A 10-year-old boy with epidermolysis bullosa simplex (Weber-Cockayne variant) together with leukocytoclastic vasculitis is presented. He was admitted to the hospital with the provisional diagnoses of infected epidermolysis bullosa simplex or drug eruption. On the sixth day of hospitalization he developed palpable purpura, abdominal pain and bloody diarrhea, together with hematuria and proteinuria. A generalized tonic-clonic convulsion, changes in mental status, fluctuations in arterial blood pressure and intractable pain in his extremities occurred during the course of hospitalization. Systemic pulse steroid therapy, antibiotics, and antihypertensive and anticonvulsive drugs were given. On the 30th day of hospitalization, a skin graft was performed to replace a large tissue defect on his left hand. Despite high dose steroid therapy, his hematuria, proteinuria and hypertension continued after his discharge, suggesting a steroid-resistant renal pathology, such as focal glomerulosclerosis, that occurred secondary to leukocytoclastic vasculitis.     

Epidermolysis bullosa: pathophysiology and nursing care

Epidermolysis bullosa (EB) is defined as a group of skin disorders that presents as blistering of the skin in varying degrees of severity. Most cases are inherited, but rare cases may be acquired. There are three main types: simplex, junctional, and dystrophic. The dermal-epidermal junction of the newborn skin is a vital area of attachment. Any defects in the components that comprise this junction can lead to fragility of the skin. EB diagnosis and testing can be per formed both prenatally and postnatally. There is no cure for EB. Treatment revolves around supportive care and prevention of complications. The NICU nurse plays an important role on the multidisciplinary team as primary caregiver to the infant and educator to the family.     

Herlitz syndrome and "pyloric atresia"

The aetiological and pathogenic relation between junctional epidermolysis bullosa (Herlitz) and prepyloric and pyloric obstruction in newborns with junctional epidermolysis bullosa is still unknown. There are two different hypotheses; one suggesting two distinct genetically related disorders (namely junctional epidermolysis bullosa and congenital pyloric atresia), the other suggesting an intrauterine mucosal damage in junctional epidermolysis bullosa. We report two infants suffering from junctional epidermolysis bullosa, Herlitz-type, verified by electron microscopy, and from connatal prepyloric and pyloric obstruction. In both cases we could demonstrate proliferative inflammation at the prepyloric antrum and pylorus as the cause of the obstruction but no complete obliteration of the pyloric channel. These findings point to an intrauterine event impacting the mucosa of the gastrointestinal tract in patients with junctional epidermolysis bullosa of the Herlitz-type and don't comply with the hypothesis of two different but genetically related diseases.     

Effective esophageal balloon dilation for esophageal stenosis in recessive dystrophic epidermolysis bullosa.

Recessive dystrophic epidermolysis bullosa (RDEB) is an inherited disorder of squamous epithelium that results in dystrophic scarring of the skin after minor trauma. RDEB is classified into two subtypes: Hallopeau-Siemens (HS) and non-Hallopeau-Siemens (nHS). Although severe scarring of the skin is the most common and obvious complication of the disease, esophageal scarring with formation of long strictures may also develop. Treatment options for esophageal stenosis in patients with RDEB include steroids, hyperalimentation, esophageal dilation and replacement. This report describes a child who was dilated immediately after diagnosis of severe esophageal stenosis subsequent to nHS-RDEB and managed successfully. Endoscopic esophageal balloon dilation under fluoroscopic control was very useful for detecting the region of stenosis and bougienage. The literature on such injuries is reviewed here, and the problems associated with the treatment of children with esophageal stenosis associated with RDEB are discussed.     

Aplasia cutis congenita. A case report and annotation

Aplasia cutis congenita (ACC) including epidermolysis bullosa (EB) are rare congenital conditions. In ACC there is a localised absence of skin while in EB blistering occurs with a split at the epidermal or dermal level. In the past these 2 conditions have been reported to occur in the same patient. A case of a Gurkha baby girl illustrating just such an entity with severe erosive defects over the head, face, trunk and acral parts of the limbs presenting at birth is reported. There was also widespread blistering over the chest, abdomen and back. The baby died after 3 days from serious complications.     

Laryngo-onycho-cutaneous syndrome: an inherited epithelial defect.

Three children with an unusual but clearly defined combination of clinical findings that appear to have been inherited in an autosomal recessive manner are described. All had developed laryngeal abnormalities, chronic skin ulceration, nail dystrophy, and conjunctival disease in infancy. In every case, dental enamel was hypoplastic and both skin and mucosal surfaces demonstrated increased susceptibility to trauma. Progression of disease occurred, to life threatening respiratory obstruction in two cases and to effective blindness and fatal respiratory obstruction in the third child. All of these children came from the Pakistani ethnic group. No medical treatment has halted progression of this disease but laser therapy has been partially successful in alleviating laryngeal manifestations. Ultrastructural and immunohistological examination of unaffected skin was undertaken in each child. No abnormality was found in the child with the mildest clinical disease. Both of the other children showed abnormal hemidesmosomes on ultrastructural examination. The most severely affected child also had abnormally weak immunoreactivity with antibodies G71 and GB3 directed against basal cell alpha 6 beta 4 integrin and the basement membrane glycoprotein nicein respectively. These abnormal findings are also seen in skin from patients with junctional epidermolysis bullosa. These three children have the laryngo-onycho-cutaneous syndrome, which may not be rare in their ethnic group. The available clinical and pathological evidence is consistent with this syndrome being caused by an inherited defect affecting the lamina lucida of the skin basement membrane zone. The laryngo-onycho-cutaneous syndrome may therefore represent a new and distinctive type of junctional epidermolysis bullosa.     

Management of digestive lesions associated to congenital epidermolysis bullosa

Background:

Congenital epidermolysis bullosa (CEB) is a rare genodermatosis. The digestive system is very frequently associated with skin manifestations. Pyloric atresia (PA) and oesophageal stenosis (OS) are considered the most serious digestive lesions to occur. The aim of this work is to study the management and the outcome of digestive lesions associated to CEB in four children and to compare our results to the literature.

Patients and Methods:

A retrospective study of four observations: Two cases of PA and two cases of OS associated to CEB managed in the Paediatric Surgery Department of Fattouma Bourguiba Teaching Hospital in Monastir, Tunisia.

Results:

Four patients, two of them are 11 and 8 years old, diagnosed as having a dystrophic epidermolysis bullosa since the neonatal period. They were admitted for the investigation of progressive dysphagia. Oesophageal stenosis was confirmed by an upper contrast study. Pneumatic dilation was the advocated therapeutic method for both patients with afavourable outcome. The two other patients are newborns, diagnosed to have a CEB because of association of PA with bullous skin lesions with erosive scars. Both patients had a complete diaphragm excision with pyloroplasty. They died at the age of 4 and 3 months of severe diarrhoea resistant to medical treatment.

Conclusion:

Digestive lesions associated to CEB represent an aggravating factor of a serious disease. OS complicating CEB is severe with difficult management. Pneumatic dilatation is the gold standard treatment method. However, the mortality rate in PA with CEB is high. Prenatal diagnosis of PA is possible, and it can help avoiding lethal forms.Key words: Congenital epidermolysisbullosa, oesophageal stenosis, pyloric atresia