Prenatal diagnosis of junctional epidermolysis bullosa associated with pyloric atresia

(New) antenatal ultrasound signs of fetal junctional epidermolysis bullosa: A case report and systematic review of literature

Epidermolysis bullosa is a rare hereditary autosomal disease that is included in the heterogeneous group of genodermatosis. It is characterized by skin and mucous membranes fragility and denudation, and it can be associated with pyloric atresia. Prognosis is often poor, and death can occur in neonatal period due to severe sepsis. We present a case of fetal junctional epidermolysis bullosa in a consanguineous couple, highly suggested by previous obstetric history and several antenatal ultrasound signs, such as polyhydramnios, gastric enlargment, the "snowflake sign", abnormal external ears, signs of skin desquamation, lower limbs anomalies and chorioamniotic membrane separation. We describe a marked perioral hipoecogenicity as a novel sign of skin-mucous denudation, which could be helpful for future diagnosis. A review of literature, focused specifically on the antenatal sonography role, is also reported. Prenatal ultrasound-based diagnosis of epidermolysis bullosa is difficult, especially in apparently low risk contexts, but may be possible.

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.

Carmi Syndrome in a Preterm Neonate: A Multidisciplinary Approach and Ethical Challenge

Epidermolysis bullosa (EB) is characterized by blistering of the skin and mucosal erosions caused by hemidesmosomal abnormalities. EB is divided into 3 major subgroups depending on the particular location of tissue separation: EB simplex, dystrophic EB, and junctional EB. Junctional EB (JEB) can further be broken down into Herlitz, non-Herlitz, and JEB with pyloric atresia (Carmi syndrome) depending on genetic and histologic testing. When extensive, management of a patient with EB can be challenging due to not only cutaneous but also extracutaneous manifestations as well. Families and health care teams are often faced with difficult decisions in their infant's best interest. We report a case of a preterm neonate with Carmi syndrome and unique findings on immunofluorescence studies. The patient's course was complicated by multisystem involvement and ultimately death. A multidisciplinary approach was crucial in the light of diagnostic, therapeutic, and ethical challenges.

A Nonlethal Case of Junctional Epidermolysis Bullosa and Congenital Pyloric Atresia: Compound Heterozygosity in a Patient with a Novel Integrin Beta 4 Gene Mutation

We report a case of nonfatal junctional epidermolysis bullosa and pyloric atresia in a newborn. We identified a substitution (c.914C>T) for the integrin β4 gene that has been associated with favorable outcome. A novel mutation (c.2011T>G) of unknown significance was also found in this patient who is now thriving.

Epidermolysis bullosa and congenital pyloric atresia

The association between epidermolysis bullosa (EB) and pyloric atresia (PA) is rare but well documented. Herein, we report a case of EB associated with congenital PA. A female baby, weighing 1480 g, was born vaginally to a 31-year-old gravida 7 lady at 33 weeks of gestation. Polyhydramnios was detected on antenatal assessment. The parents were non-consanguineous Saudis with no family history of significant illness. At birth, well-demarcated areas of peeled skin were present over knees, left leg and periumbilical region. Systemic examination revealed no other abnormality. On second day, the patient developed recurrent vomiting and abdominal distension. An abdominal X-ray revealed a single gastric gas bubble suggesting pyloric obstruction. Following gastroduodenostomy, the baby developed severe sepsis with multiorgan dysfunction and expired on 25th day of life. Skin biopsy showed cleavage within lamina lucida.

Connective tissue and related disorders and preterm birth: clues to genes contributing to prematurity

To identify candidate genes contributing to preterm birth, we examined the existing literature on the association between known disorders of connective tissue synthesis and metabolism and related diseases and prematurity. Our hypothesis was that abnormal matrix metabolism contributes to prematurity by increasing risk of preterm premature rupture of membranes (PPROM) and cervical incompetence. Based on this review, we identified gene mutations inherited by the fetus that could predispose to preterm birth as a result of PPROM. The responsible genes include COL5A1, COL5A2, COL3A1, COL1A1, COL1A2, TNXB, PLOD1, ADAMTS2, CRTAP, LEPRE1 and ZMPSTE24. Marfan syndrome, caused by FBN1 mutations, and polymorphisms in the COL1A1 and TGFB1 genes have been associated with cervical incompetence. We speculate that an analysis of sequence variation at the loci noted above will reveal polymorphisms that may contribute to susceptibility to PPROM and cervical incompetence in the general population.

Pyloric atresia associated with epidermolysis bullosa--three cases presenting in three months

Three neonates presenting with pyloric atresia and epidermolysis bullosa are described in this report. Two babies underwent surgery for pyloric atresia, and 1 of these has survived until 3 months of age with no complications. The clinical presentation and complications of the pyloric atresia-epidermolysis bullosa syndrome are discussed with a brief review of literature.

Distal foregut atresias in consecutive siblings and twins in the same family

The distal foregut comprises the antrum of the stomach and supra-ampullary region of the duodenum. In this part of the gut, intraluminal mucosal diaphragms, webs, membranes (type I), and rarely solid cord (type II) atresias are occasionally seen in clinical practice. Due to increased awareness, the number of reported cases has increased in recent years. These foregut lesions are known to have a strong genetic association. Both antral (AA) and duodenal atresias (DA) may occur as potentially curable sporadic cases or in combination with lethal malformations such as hereditary multiple gastrointestinal atresias affecting the fore-, mid-, and hindgut. The association of AA and junctional epidermolysis bullosa lethalis is well-known. We describe an unusual occurrence of foregut atresias in two consecutive siblings and a pair of monozygous twins. The involvement of four siblings in a single family is extraordinary and as yet unreported. This cluster of cases not only lends a strong support to a genetic origin, but also the mode of transmission, despite the absence of a history of consanguinity. It indicates that atresia of the gastric antrum and supra-ampullary DA are etiologically closely related. It is also possible that the discordant expression in the twins could be a pleiotropic effect of the same genetic factor. Attempts are made to explain the possible pathogenesis of this unusual atresia and relate it to other associated anomalies.

Alpha 6 beta 4 integrin abnormalities in junctional epidermolysis bullosa with pyloric atresia

Junctional epidermolysis bullosa with pyloric atresia (JEB-PA) (MIM 226730) is an autosomal recessive disorder resulting from mutations in the genes encoding alpha 6 beta 4 integrin (ITGA6 and ITGB4). Clinically, it is characterized by mucocutaneous fragility and gastrointestinal atresia, which most commonly affects the pylorus. Additional features of JEB-PA include involvement of the urogenital tract, aplasia cutis and failure to thrive. While most affected individuals have a poor prognosis resulting in death in infancy, others have milder clinical features and a better prognosis. We report two previously undescribed homozygous ITGB4 mutations in two unrelated families, which resulted in severe skin blistering, pyloric atresia and lethality in infancy. Delineation of the mutations was used to undertake DNA-based prenatal diagnosis in subsequent pregnancies at risk for recurrence in both families. We review all previously published ITGA6 and ITGB4 mutation reports to help define genotype--phenotype correlation in this rare genodermatosis.

Pyloric atresia: five new cases, a new association, and a review of the literature with guidelines

BACKGROUND/PURPOSE

Pyloric atresia is an uncommon condition occurring in 1 of 100,000 live births. When occurring in isolation, the clinical course usually is uncomplicated after surgical treatment. However, it may occur in association with other congenital abnormalities. The authors present 5 new cases, 3 of associated abnormalities including 1 of esophageal atresia and 2 of agenesis of the gall bladder and malrotation. Agenesis of the gall bladder has not been described previously in combination with pyloric atresia. The literature has been reviewed and guidelines are suggested for the management.

METHODS

The case records of 4 neonates who presented to the author's institution between January 1998 and June 1999 and 1 who presented at another center in 1991 were reviewed. A Medline literature search was performed, and guidelines were developed for the management of this condition based on our cases and the literature review.

RESULTS

Patients 1 and 5 had no associated anomalies. Patient 2 had associated esophageal atresia, tracheoesophageal fistula, atrial septal defect, crossed renal ectopia, malrotation, and absent gall bladder. Patient 3 had a rectovestibular fistula, vaginal atresia, atrial septal defect, malrotation absent gallbladder, and absent extrahepatic portal vein. Patient 4 had epidermolysis bullosa. Patients 2 and 5 had unremarkable recoveries, patients 2 and 3 had markedly delayed gastric emptying that responded to cisapride. Patient 3 has portal hypertension and remains under close follow-up. Patient 4 died at 22 days of age of pseudomonas sepsis.

CONCLUSIONS

Based on our cases and literature review, we have adopted the following guidelines: (1) All children with pyloric atresia should be screened for multiple anomalies. (2) Delayed gastric emptying should be considered early and may respond to prokinetic agents. (3) Association with Epidermolysis bullosa should not preclude surgical treatment. (4) A skin biopsy specimen should be taken at the time of surgery for electron microscopy if there is a family history of epidermolysis bullosa.

Prenatal diagnosis as a test for genodermatoses: its past, present and future

The prenatal diagnosis (PND) of severe hereditary skin diseases started in the early 1980s using fetal skin biopsy techniques based on ultrastructural and immunohistochemical abnormalities of the fetal skin. Recent success in identifying responsible genes and demonstrating mutations in such genes has set the stage for DNA-based PND in the 1990s. Common examples of skin conditions which can be prenatally diagnosed include epidermolysis bullosa, oculocutaneous albinism and Harlequin ichthyosis in which the severity of the clinical phenotype appears to justify PND in families at risk. More recently, preimplantation diagnoses of inherited diseases have become possible using in vitro fertilization techniques. The diagnosis consists of a blastomere biopsy of the six to ten-cell embryo and a DNA analysis of single blastomeres. Disease-free embryos are selected for transfer to the uterus, thereby avoiding the need for termination of a fetus found to be affected by conventional PND. Furthermore, carrying out a PND using a single fetal cell from the maternal blood, such as nucleated erythrocytes, has become technically feasible. Although there are many questions that remain unanswered, the outlook for further development of noninvasive PND in the future appears optimistic.

Pyloric atresia-junctional epidermolysis bullosa syndrome: mutations in the integrin beta4 gene (ITGB4) in two unrelated patients with mild disease

Junctional epidermolysis bullosa associated with pyloric atresia (EB-PA; OMIM 226730) is a rare autosomal recessively inherited disease in which mucocutaneous fragility is associated with gastrointestinal atresia. This disease is usually fatal within the first few weeks or months of life even following surgical correction of the intestinal obstruction. Recently, mutations in the genes encoding the epithelial integrin alpha6beta4 (ITGA6 and ITGB4) have been identified in several patients with EB-PA. We report two unrelated patients with this disease who have survived into early childhood with mild cutaneous involvement, in whom we have identified pathogenetic mutations in ITGB4. The first patient was a compound heterozygote for a splice site mutation in exon 30 (3793 + 1G-to-A) and a non-sense mutation in exon 36 (W1478X), and the second was a compound heterozygote for a missense mutation in exon 3 (C38R) and a 1 bp deletion in exon 36 (4776delG). Although the non-sense and deletion mutations are predicted to result in markedly reduced beta4 integrin mRNA levels, the presence of the missense or splice site mutation on the second allele may enable the synthesis of some functional, albeit perturbed, beta4 polypeptide. Determination of the molecular mechanisms in these two cases increases our understanding of EB-PA and may enable correlation between genotype and phenotype.

Novel ITGB4 mutations in lethal and nonlethal variants of epidermolysis bullosa with pyloric atresia: missense versus nonsense

Epidermolysis bullosa with pyloric atresia (EB-PA), an autosomal recessive genodermatosis, manifests with neonatal cutaneous blistering associated with congenital pyloric atresia. The disease is frequently lethal, but nonlethal cases have also been reported. Expression of the alpha6 beta4 integrin is altered at the dermal-epidermal basement-membrane zone; recently, mutations in the corresponding genes (ITGA6 and ITGB4) have been disclosed in a limited number of patients, premature termination codons in both alleles being characteristic of lethal variants. In this study, we have examined the molecular basis of EB-PA in five families, two of them with lethal and three of them with nonlethal variants of the disease. Mutation analysis disclosed novel lesions in both ITGB4 alleles of each proband. One of the patients with lethal EB-PA was a compound heterozygote for premature termination-codon mutations (C738X/4791delCA), whereas the other patient with a lethal variant was homozygous for a missense mutation involving a cysteine residue (C61Y). The three nonlethal cases had missense mutations in both alleles (C562R/C562R, R1281W/R252C, and R1281W/R1281W). Immunofluorescence staining of skin in two of the nonlethal patients and in one of the lethal cases was positive, yet attenuated, for alpha6 and beta4 integrins. These results confirm that ITGB4 mutations underlie EB-PA and show that missense mutations may lead to nonlethal phenotypes.

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.

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.

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.

Altered expression of a new antigen of the dermal-epidermal junction (NU-T2 DEJ Ag) in junctional epidermolysis bullosa

NU-T2 antigen (Ag) is a new and recently described antigen of the dermal-epidermal junction, recognized by an anti-CD1b monoclonal antibody denominated NU-T2. We studied NU-T2 Ag expression in junctional epidermolysis bullosa (13 patients) and in other forms of hereditary epidermolysis bullosa (23 patients), comparing the results with nicein expression. In junctional epidermolysis bullosa gravis type no differences were found between the expression of NU-T2 and nicein, both being negative in bullous as well as in non-bullous skin. Interestingly, in mitis type junctional epidermolysis bullosa, NU-T2 Ag was found to be absent or reduced in five of six patients both in lesional and in uncleaved skin. When compared with nicein expression, clearcut differences were found, further suggesting that these two antigens are different. These data confirm that NU-T2 Ag is a novel epitope of the dermal-epidermal junction, probably relevant in dermal-epidermal cohesion, and it could be responsible, together with nicein, 19-DEJ-1 and other adhesion molecules, for the different subtypes of junctional epidermolysis bullosa. Finally, NU-T2 monoclonal antibody is a new relevant tool for the diagnosis, classification, and prenatal diagnosis of junctional epidermolysis bullosa.

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.

Prenatal testing in a fetus at risk for autosomal dominant polycystic kidney disease and autosomal recessive junctional epidermolysis bullosa with pyloric atresia

Amniocentesis and fetal skin biopsies were performed at 18 weeks of gestation in a fetus at risk for autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive junctional epidermolysis bullosa (EBJ) with pyloric atresia. A previous son of the couple under investigation had died at 3 months of EBJ. The mother of the propositus has ADPKD. Genetic linkage studies were carried out in 11 relatives (4 with ADPKD), and on fetal DNA obtained from cultured amniocytes, using 8 flanking DNA markers tightly linked to the PKD1 locus on chromosome 16p, and a DNA marker linked to another putative ADPKD locus on chromosome 2p. The linkage results indicated that the fetus had not inherited the ADPKD chromosome from the affected mother, with a diagnostic accuracy of > 99%. Ultrastructural and immunohistochemical analyses of multiple fetal skin biopsies showed no EBJ-associated abnormalities. Thus, combining recent morphological and molecular diagnostic methods, we could show that the fetus was free from both diseases. After 40 weeks of gestation, a normal male infant was delivered.

Prenatal detection of epidermolysis bullosa letalis with pyloric atresia in a fetus by abnormal ultrasound and elevated alpha-fetoprotein

We report on the prenatal diagnosis of epidermolysis bullosa letalis with pyloric atresia in a pregnancy not known to be at risk for this condition. Elevated maternal serum alpha-fetoprotein levels led to ultrasonography which demonstrated gastric dilatation, consistent with pyloric atresia, and echogenic particles in the amniotic fluid, the "snowflake sign," previously described in two pregnancies of fetuses with disorders of skin sloughing. Amniotic fluid alpha-fetoprotein was markedly elevated and the acetylcholinesterase was positive. The diagnosis of epidermolysis bullosa letalis with pyloric atresia was confirmed after delivery by electron microscopy of fetal skin which showed typical changes of hypoplastic absent hemidesmosomes and separation along the dermal-epidermal junction. None of these abnormal prenatal findings are consistently present in pregnancies with epidermolysis bullosa with pyloric atresia. Thus, although useful when abnormal, when the test results are normal, the need for confirmatory fetoscopy and fetal skin biopsy remains.