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

Clinical outcomes and molecular profile of patients with Carmi syndrome: A systematic review and evidence quality assessment

PURPOSE

Carmi syndrome is a rare genetic disorder characterized by junctional epidermolysis bullosa (JEB) and pyloric atresia (PA). We reviewed the clinicopathologic and molecular features of patients with Carmi syndrome to identify predictors of clinical outcome and guide surgical PA repair.

METHODS

A PRISMA-compliant systematic literature review of PubMed, CINAHL, and the Cochrane Library was performed.

RESULTS

63 original studies including a total of 100 patients were included. PA type 1 and 2 were equally prevalent (47.2%, 95% CI: 34.4-60.3). Heineke-Mikulicz pyloroplasty (96%, 95% CI: 78.8-99) and gastroduodenostomy (72%, 95% CI: 52.2-85.9) were the most common type 1 and 2 PA repairs, respectively. Seventy lethal cases were identified (74.5%, 95% CI: 64.8-83.5). Of the 73 patients that received an operation, 49 died (67.1%, 95% CI: 55.7-76.8) and 24 survived (32.9%, 95% CI: 23.2-44.3). Integrin α6β4 expression was absent or markedly reduced in lethal cases. Integrin α6, plectin-1, cephalic integrin β4 (exon 3 to intron 11), and premature termination codon mutations were also associated with poor prognosis.

CONCLUSIONS

Although Carmi syndrome typically has poor prognosis, 1 in 4 patients exhibits nonlethal phenotypes. Immunofluorescence mapping and genetic consultation can guide surgical intervention and provide valuable family planning information.

EVIDENCE RATING/CLASSIFICATION

Prognosis study, Level IV.

Pyloric atresia associated with multiple intestinal atresias and pylorocholedochal fistula

Although congenital pyloric atresia commonly occurs in isolation, it has rarely been reported in association with other alimentary tract atresias. This is a report of a newborn with congenital pyloric atresia associated with duodenal atresia, jejunal atresia, apple-peel ileal atresia, and pylorocholedochal fistula. Preoperative diagnosis was duodenal atresia because of bilious vomiting, and erect radiogram showed double bubble sign. The presented case is the first report of such an association.

Junctional epidermolysis bullosa gravis (Herlitz): diagnostic and genetic aspects

We report on a boy suffering from lethal junctional epidermolysis bullosa gravis (JEBH) (Herlitz-type) (OMIM 226700). Screening for mutations of LAMB3 gene with polymerase chain reaction (PCR) amplification of all exons from genomic DNA and subsequent heteroduplex analysis and dideoxynucleotide sequencing of heteroduplex forming PCR products disclosed two mutations: the recurrent maternal mutation R635X and the novel paternal mutation 1629insG, both in exon 14 of LAMB3. Both mutations lead to a premature termination code, non-sense mediated mRNA decay and to absence of the synthesis of the beta3 chain of laminin 5. During the mutation screening of the index patient a second pregnancy was ascertained. After amniocentesis (14 + 1 week of pregnancy), prenatal diagnosis from fetal cells was performed and compound heterozygosity for both mutations was evident. The consultants decided to have a termination of pregnancy shortly after the diagnosis. Remarkable skin fragility of the fetus was evident by clinical examination. Complete absence of laminin 5 could be demonstrated by immunofluorescence staining. By the third pregnancy of this couple so far screened for mutations by chorionic villus sampling for prenatal molecular diagnosis a healthy but heterozygous child is expected.

Herlitz junctional epidermolysis bullosa: a case report and review of current diagnostic methods

We report an infant with Herlitz junctional epidermolysis bullosa (JEB) presenting at birth with erosions on the scalp, thigh and periumbilical area in addition to nail abnormalities. Ultrastructural studies demonstrated a split through the lamina lucida with poorly formed hemidesmosomes and no clearly defined subbasal dense plates. Indirect immunofluorescence staining with antibodies GB3 (antilaminin 5) and 19-DEJ-1 (antiuncein) was totally absent. These findings, in combination with the clinical picture, favor a diagnosis of Herlitz JEB. Immunohistochemistry findings greatly facilitated an accurate diagnosis, which is essential in view of the poor prognosis for patients with this form of junctional epidermolysis bullosa.

Novel ITGB4 mutations in a patient with junctional epidermolysis bullosa-pyloric atresia syndrome and altered basement membrane zone immunofluorescence for the alpha6beta4 integrin

Immunofluorescence studies of junctional epidermolysis bullosa with pyloric atresia (JEB-PA) have suggested abnormalities in the expression of the alpha6 beta4 integrin, an integral component of hemidesmosomes. In this study, we examined a family with two affected individuals with JEB-PA for mutations in the ITGA6 and ITGB4 genes which encode the alpha6 and beta4 integrin polypeptides, respectively. Mutation detection strategy based on PCR amplification of genomic DNA, followed by heteroduplex analysis and direct nucleotide sequencing, did not reveal sequence variants in ITGA6. Putative pathogenic mutations, however, were identified in both ITGB4 alleles. Specifically, the proband was a compound heterozygote for a 1-bp maternal deletion, 3434delT, and an 8-bp paternal deletion, 4050de18. Both mutations result in a frameshift and premature termination codon downstream from the deletion. At the protein level, immunofluorescence of the skin of the proband revealed negative staining for the integrin alpha6 and markedly reduced staining for the beta4 subunit. Thus, the results support the notion of close association of the alpha6 beta4 integrin subunits and further attest to the critical role of this integrin in providing physiologic stability to the dermal-epidermal junction.

Gastric outlet obstruction and epidermolysis bullosa

We describe a case of pyloric atresia coexisting with epidermolysis bullosa, almost certainly of the junctional type. The coexistence of pyloric atresia and junctional epidermolysis bullosa (PA-JEB syndrome) has been repeatedly observed. This syndrome has several clinical features that distinguish it from Herlitz junctional epidermolysis bullosa (JEB). These include a lack of prominent granulation tissue formation and increased frequencies of genitourinary tract involvement and ear anomalies. Aplasia cutis congenita is sometimes present; esophageal atresia is uncommonly present. In all 12 patients examined to date, normal basement membrane zone expression of laminin-5 biochemically distinguishes PA-JEB syndrome from Herlitz JEB. Mutations in the beta 4 integrin gene have been observed in one patient with PA-JEB syndrome. Thus there are both clinical and biochemical reasons to separate the PA-JEB syndrome from Herlitz JEB. This is the second known case of papillary hyperplasia of the amnion to be seen in any setting. The other was a case of JEB without pyloric atresia.

Defective integrin alpha 6 beta 4 expression in the skin of patients with junctional epidermolysis bullosa and pyloric atresia

Junctional epidermolysis bullosa (JEB) is a heterogeneous group of rare inherited skin disorders in which defects in cell adhesion components cause incomplete formation of hemidesmosomes. We have immunohistochemically examined the skin from ten JEB patients (JEB gravis, n = 4; JEB mitis, n = 3; JEB plus pyloric atresia [JEB/PA], n = 3) using monoclonal antibodies specific for the integrin adhesion receptors alpha 3 beta 1 and alpha 6 beta 4, and for the alpha 3, beta 3, and gamma 2 subunits of the basement membrane ligand, laminin 5. Consistent with our previous reports, only the JEB gravis patients without associated pyloric atresia expressed reduced or absent epitopes for laminin-5 subunits in their epidermal basement membrane. In contrast, all three JEB/PA cases showed abnormalities in integrin alpha 6 beta 4, but not in laminin 5, expression in their basal epidermal cells. Integrin beta 4 subunit was undetectable in the biopsied epidermis of these JEB/PA individuals using five different monoclonal antibodies that recognize both intra- and extracellular epitopes. The absence of the beta 4 subunit in the epidermis of JEB/PA specimens was confirmed by Western blot analysis of tissue extracts. Epidermal expression of the integrin alpha 6 subunit was variable in the JEB/PA patients. Abnormal integrin alpha 6 beta 4 expression may define the subset of JEB cases with pyloric atresia. These results strongly implicate a functional role for alpha 6 beta 4 in the formation of complete hemidesmosomes and in stable adhesion of basal keratinocytes to the basement membrane in vivo.

Beta4 integrin is required for hemidesmosome formation, cell adhesion and cell survival

The integrin heterodimer alpha 6 beta 4 is expressed in many epithelia and in Schwann cells. In stratified epithelia, alpha 6 beta 4 couple with BPAG1-e and BPAG2 to form hemidesmosomes, attaching externally to laminin and internally to the keratin cytoskeleton. To explore the function of this atypical integrin, and its relation to conventional actin-associated integrins, we targeted the removal of the beta 4 gene in mice. Tissues that express alpha 6 beta 4 are grossly affected. Stratified tissues are devoid of hemidesmosomes, display only a very fragile attachment to the basal lamina, and exhibit signs of degeneration and tissue disorganization. Simple epithelia which express alpha 6 beta 4 are also defective in adherence, even though they do not form hemidesmosomes. In the absence of beta 4, alpha 6 is dramatically downregulated, and other integrins do not appear to compensate for the loss of this heterodimer. These data have important implications for understanding integrin function in cell-substratum adhesion, cell survival and differentiation, and for understanding the role of alpha 6 beta 4 in junctional epidermolysis bullosa, an often lethal human disorder with pathology similar to our mice.

Deficiency of the integrin beta 4 subunit in junctional epidermolysis bullosa with pyloric atresia: consequences for hemidesmosome formation and adhesion properties

Junctional epidermolysis bullosa (JEB) comprises a group of inherited autosomal recessive blistering disorders characterized by dermo-epidermal separation through the lamina lucida of the basement membrane. We identified a patient with JEB associated with pyloric atresia (PA), in whom the integrin beta 4 subunit was completely absent. At the ultrastructural level, the hemidesmosomes were reduced in number, appeared rudimentary and lacked a subbasal dense plate and frequently an inner attachment plaque. However, keratin filaments were still anchored to the cytoplasmic plaque of the hemidesmosome. Immunofluorescence analysis showed that the beta 4 subunit was absent in the skin of the PA-JEB patient, whereas the alpha 6 subunit appeared to be normally distributed along the basement membrane zone, as were the other hemidesmosomal components BP230, BP180 and HD1. Furthermore, the alpha 3 and beta 1 subunits were not only detected at the lateral membranes of basal cells in PA-JEB skin, as in normal skin, but also along the basement membrane zone. The few hemidesmosome-like structures found in cultured keratinocytes from the PA-JEB patient contained the hemidesmosomal components BP230, BP180 and HD1, but not the integrin alpha 6 subunit. Like alpha 3, this subunit was colocalized with vinculin in focal contacts at the ends of actin stress fibers. Immunoprecipitation analysis revealed that alpha 6 was associated with beta 1 on PA-JEB keratinocytes, whereas normal human keratinocytes (NHKs) exclusively express alpha 6 beta 4 on their cell surface. The initial adhesion of PA-JEB and normal keratinocytes to laminin-1 and laminin-5, both ligands for alpha 6 beta 1 and alpha 6 beta 4, was similar. In migration assays, the PA-JEB keratinocytes were more motile on laminin-5 than normal keratinocytes. Our observations indicate that the integrin alpha 6 beta 4 plays a crucial role in the proper assembly of hemidesmosomes and in the stabilization of the dermal-epidermal junction. The fragility of the skin and the blistering in this patient appear to have been due to the deficiency of the integrin beta 4 subunit, which results in the formation of too few and structurally abnormal hemidesmosomes.

Junctional epidermolysis bullosa and pyloric atresia: a distinct entity. Clinical and pathological studies in five patients

Junctional epidermolysis bullosa (JEB) associated with pyloric atresia (PA) is a distinct entity which is inherited as an autosomal recessive disorder. We describe five patients with this association; four died in the neonatal period and one is still alive at 4 years of age. The cutaneous lesions in these patients are identical or similar to those in other JEB subtypes. Urinary tract involvement is part of the syndrome and presents a problem for long-term survival. Using the monoclonal antibody GB3 we investigated skin biopsies from three of our patients and showed normal expression in all of them, unrelated to the outcome of their disease. This indicates that the GB3 monoclonal antibody is without prognostic significance in this syndrome. It is clear that JEB with PA is a distinct entity. The molecular basis as yet is unknown.

Epidermolysis bullosa associated with pyloric, esophageal, and anal atresia: a case report

The association of epidermolysis bullosa (EB) and pyloric atresia (PA) in newborns is rare but has been well described. It has been reported that in patients with EB, the esophageal, gastric, intestinal, and colonic mucosae are affected. The authors report a case of EB and PA associated with esophageal and anal atresia in a newborn. To our knowledge, these associations had not been reported in the English-language literature.

Integrin beta 4 mutations associated with junctional epidermolysis bullosa with pyloric atresia

Pyloric atresia associated with junctional epidermolysis bullosa (PA-JEB), is a rare inherited disorder characterized by pyloric stenosis and blistering of the skin as primary manifestations. We demonstrate that in one PA-JEB patient the disease resulted from two distinct mutations in the beta 4 integrin gene alleles. The paternal mutation consists of a one base pair deletion causing a shift in the open reading frame, and a downstream premature termination codon. The maternal mutation occurs in a donor splice site, and results in in-frame exon skipping involving the cytoplasmic domain of the polypeptide. Our results implicate mutations in the beta 4 integrin gene in some forms of PA-JEB.

Gastric outlet obstruction and gastric infarct in junctional epidermolysis bullosa

A newborn boy had junctional epidermolysis bullosa, duodenal obstruction, and gastric infarction, a newly described combination that extends the spectrum of gastrointestinal findings associated with junctional epidermolysis bullosa. The infant underwent feeding jejunostomy, but died 16 days after birth. This report emphasizes the need for gastrointestinal assessment in any neonate suspected of having epidermolysis bullosa, especially if the pregnancy was complicated by polyhydramnios.

Junctional epidermolysis bullosis: defects in expression of epiligrin/nicein/kalinin and integrin beta 4 that inhibit hemidesmosome formation

Junctional epidermolysis bullosis (JEB) is a heterogeneous inherited blistering disorder of human epithelial basement membranes (BMs). Characteristically, the epidermis detaches from the BM between the basal cells and the lamina lucida due to reduced numbers of hemidesmosomes (HDs). Attempts to identify a candidate gene for JEB led to the characterization of nicein, a protein complex in normal BMs that is absent from BMs of patients with JEB gravis. In independent research, two related BM glycoproteins, epiligrin and kalinin, were identified as functional adhesion components of HDs. Epiligrin was characterized as a BM ligand for basal cell adhesion via integrins alpha 3 beta 1 in focal adhesions and alpha 6 beta 4 in HDs. Kalinin was characterized as an adhesive ligand and a component of anchoring filaments. Recent antibody and sequence studies on epiligrin/nicein/kalinin have identified limited homologies with laminin. Ongoing studies in multiple laboratories seek to identify mutations in one or more of the three subunits of epiligrin that are causal in JEB gravis. Consistent with the genetic heterogeneity of JEB, we have identified a patient with a variant form of JEB that is associated with pyloric atresia. This patient has negligible HDs, normal epiligrin, but reduced expression of integrin beta 4. A defect in the beta 4 expression may define a subset of JEB cases that also present with pyloric atresia. These results testify to the dual requirements for epiligrin in the BM and integrin beta 4 in the plasma membrane in regulating function of HDs in epithelium.

Prenatal exclusion of pyloric atresia-junctional epidermolysis bullosa syndrome

BACKGROUND

The pyloric atresia--junctional epidermolysis bullosa (PA-JEB) syndrome is an autosomal recessive disorder with a poor prognosis. Electron microscopy of fetal skin has been the only reliable method for prenatal diagnosis.

OBJECTIVE

The purpose of this study was to make the prenatal diagnosis of PA-JEB syndrome with a more reliable method by means of immunocytochemical probes.

METHODS

Expression of a range of basement membrane antigens was examined in different types of JEB. On the basis of the results, a fetal skin biopsy specimen was obtained for prenatal diagnosis.

RESULTS

In PA-JEB syndrome (n = 2), GB3 antigen (BM600) was normally expressed; the 19-DEJ-1 antigen was completely absent. In fetal skin at risk for PA-JEB syndrome, the 19-DEJ-1 antigen was normally expressed, and no ultrastructural abnormality was found by electron microscopy. A normal male infant was delivered at 38 weeks of pregnancy.

CONCLUSION

19-DEJ-1 monoclonal antibody serves as a useful probe for the prenatal diagnosis of PA-JEB syndrome.

Kalinin is abnormally expressed in epithelial basement membranes of Herlitz's junctional epidermolysis bullosa patients

Kalinin is an extracellular adhesion molecule specific to epithelial basement membranes (BM) identified as a component of anchoring filaments of hemidesmosomes. This heterotrimeric protein is synthesized by cultured normal human keratinocytes and is involved in cell attachment. In indirect immunofluorescence studies, the epidermal BM of patients with junctional epidermolysis bullosa (JEB) of Herlitz's type were found not to be reactive with the anti-kalinin monoclonal antibodies ka146 and K140 and displayed a decreased immunoreactivity to two anti-kalinin antibodies cross-reacting with K-laminin, an anchoring filament component recently described. The intrinsic defect of JEB keratinocytes in the synthesis of kalinin was further documented by indirect immunofluorescence on in vitro cultures of these cells. In non-Herlitz JEB patients, staining of BM was constantly detected. Impairment of expression of kalinin correlated with the lack of reactivity to the monoclonal antibody GB3, which detects the BM component nicein/BM600. These results clearly demonstrate a defect of kalinin expression in epithelial basement membranes of Herlitz JEB patients and suggest that kalinin may play a role in the pathogenesis of the disease. Further studies are in progress to define possible relationships between kalinin and nicein.