Genetic factors in esophageal atresia, tracheo-esophageal fistula and the VACTERL association: roles for FOXF1 and the 16q24.1 FOX transcription factor gene cluster, and review of the literature

Esophageal Atresia with Tracheoesophageal Fistula Is Associated with Consanguinity

OBJECTIVE

To examine the association between nonsyndromic esophageal atresia with tracheoesophageal fistula (EA-TEF) and consanguinity.

STUDY DESIGN

A retrospective study comparing the incidence of EA-TEF between a low-consanguineous Jewish population and a high-consanguineous Bedouin population. All patients were treated at Soroka University Medical Center, the only tertiary medical center in southern Israel.

RESULTS

From 2000 to 2022, 579 130 children were born in southern Israel, and 386 915 (66.8%) were Jewish, and 192 215 were Bedouin Muslims. A total of 96 patients were diagnosed with EA-TEF; 83 of them were nonsyndromic. The incidence of EA-TEF was 1.66 cases per 10 000 live births and was statistically higher among the Bedouin population (3 vs 0.95 cases per 10 000 live births; P < .001). The consanguinity rate among the Bedouin group was higher compared with the Jewish (67.8% vs 0%; P < .001). There were no differences in other risk factors.

CONCLUSIONS

The incidence of EA-TEF is higher among the Bedouin population that lives in the same geographic region and has the same medical access as the Jewish population, proposing consanguinity as a risk factor for EA-TEF.

Pulmonary Hypertension in Developmental Lung Diseases

Diverse genetic developmental lung diseases can present in the neonatal period with hypoxemic respiratory failure, often associated with with pulmonary hypertension. Intractable hypoxemia and lack of sustained response to medical management should increase the suspicion of a developmental lung disorder. Genetic diagnosis and lung biopsy are helpful in establishing the diagnosis. Early diagnosis can result in optimizing management and redirecting care if needed. This article reviews normal lung development, various developmental lung disorders that can result from genetic abnormalities at each stage of lung development, their clinical presentation, management, prognosis, and differential diagnoses.

Single-cell analysis reveals the spatial-temporal expression of genes associated with esophageal malformations

Understanding the molecular mechanisms of congenital diseases is challenging due to their occurrence within specific developmental stages. Esophageal malformations are examples of such conditions, characterized by abnormalities in the development of esophagus during embryogenesis. These developmental malformations encompass a range of anomalies, including esophageal atresia, and tracheoesophageal fistula. Here, we investigated the preferential expression of 29 genes that are implicated in such malformations and their immediate interactome (a total of 67 genes). We conducted our analyses across several single-cell atlases of embryonic development, encompassing approximately 150,000 cells from the mouse foregut, 180,000 cells from human embryos, and 500,000 cells from 24 human organs. Our study, spanning diverse mesodermal and endodermal cell populations and early developmental stages, shows that the genes associated with esophageal malformations show their highest cell-type specific expression in lateral plate mesoderm cells and at the developmental stage of E8.75-E9.0 days. In human embryos, these genes show a significant cell-type specific expression among subpopulations of epithelial cells, fibroblasts and progenitor cells including basal cells. Notably, members of the forkhead-box family of transcription factors, namely FOXF1, FOXC1, and FOXD1, as well as the SRY-box transcription factor, SOX2, demonstrate the most significant preferential expression in both mouse and human embryos. Overall, our findings provide insights into the temporal and cellular contexts contributing to esophageal malformations.

Pediatric Aerodigestive Medicine: Advancing Collaborative Care for Children With Oropharyngeal Dysphagia

OBJECTIVES

Aerodigestive disorders encompass various pathological conditions affecting the lungs, upper airway, and gastrointestinal tract in children. While advanced care has primarily occurred in specialty centers, many children first present to general pediatric gastroenterologists with aerodigestive symptoms necessitating awareness of these conditions. At the 2021 Annual North American Society for Pediatric Gastroenterology, Hepatology and Nutrition meeting, the aerodigestive Special Interest Group held a full-day symposium entitled, Pediatric Aerodigestive Medicine: Advancing Collaborative Care of Children with Aerodigestive Disorders. The symposium aimed to underline the significance of a multidisciplinary approach to achieve better outcomes for these complex patients.

METHODS

The symposium brought together leading experts to highlight the growing aerodigestive field, promote new scientific and therapeutic strategies, share the structure and benefits of a multidisciplinary approach in diagnosing common and rare aerodigestive disorders, and foster multidisciplinary discussion of complex cases while highlighting the range of therapeutic and diagnostic options. In this article, we showcase the diagnostic and therapeutic approach to oropharyngeal dysphagia (OPD), one of the most common aerodigestive conditions, emphasizing the role of a collaborative model.

CONCLUSIONS

The aerodigestive field has made significant progress and continues to grow due to a unique multidisciplinary, collaborative model of care for these conditions. Despite diagnostic and therapeutic challenges, the multidisciplinary approach has enabled and greatly improved efficient, high-quality, and evidence-based care for patients, including those with OPD.

Identification and validation of candidate risk genes in endocytic vesicular trafficking associated with esophageal atresia and tracheoesophageal fistulas

Esophageal atresias/tracheoesophageal fistulas (EA/TEF) are rare congenital anomalies caused by aberrant development of the foregut. Previous studies indicate that rare or de novo genetic variants significantly contribute to EA/TEF risk, and most individuals with EA/TEF do not have pathogenic genetic variants in established risk genes. To identify the genetic contributions to EA/TEF, we performed whole genome sequencing of 185 trios (probands and parents) with EA/TEF, including 59 isolated and 126 complex cases with additional congenital anomalies and/or neurodevelopmental disorders. There was a significant burden of protein-altering de novo coding variants in complex cases (p = 3.3 × 10-4), especially in genes that are intolerant of loss-of-function variants in the population. We performed simulation analysis of pathway enrichment based on background mutation rate and identified a number of pathways related to endocytosis and intracellular trafficking that as a group have a significant burden of protein-altering de novo variants. We assessed 18 variants for disease causality using CRISPR-Cas9 mutagenesis in Xenopus and confirmed 13 with tracheoesophageal phenotypes. Our results implicate disruption of endosome-mediated epithelial remodeling as a potential mechanism of foregut developmental defects. Our results suggest significant genetic heterogeneity of EA/TEF and may have implications for the mechanisms of other rare congenital anomalies.

Annular pancreas in neonates; Case series and review of literatures

BACKGROUND

The annular pancreas is a rare congenital disorder of the pancreas first recognized in 1818. It is believed to result from faulty rotation of the ventral pancreatic bud in its course around the posterior aspect of the duodenal anlage. The duodenum is encircled and might be obstructed by normal pancreatic tissue. The management of the annular pancreas is still developing and under revision.

CASE PRESENTATION

Six cases of neonatal intestinal obstruction secondary to the annular pancreas diagnosed, operated on, and involved in our study. Age, gender, maturity, age at referral, birth weight, clinical presentation, imaging findings, associated congenital anomalies, treatment, complications, and hospital stay were all studied. Polyhydramnios is found in 3 cases (50%). Down syndrome was diagnosed in one case. One patient has associated malrotation. Symptoms started earlier within the first 24 hours. Vomiting was bile stained in 4 cases (66.7%). Passing meconium, sometimes frequent, does not exclude the annular pancreas. Most patients show double bubbles sign on plain abdominal X-ray. All six neonates were treated with duodenoduodenostomy with excellent results. Survival was 100% and complications were minimum.

CONCLUSION

The annular pancreas, although rare, is an important cause of neonatal duodenal obstruction. The accurate diagnosis is usually performed during laparotomy. Vomiting may contain bile or not, furthermore, passing meconium does not exclude this condition. The best and the excellent surgical option is diamond duodenoduodenostomy. This case series might be added to the registered cases of the annular pancreas to standardize the method of diagnosis and to define the best management.

From the Ground Up: Esophageal Atresia Types, Disease Severity Stratification and Survival Rates at a Single Institution

Esophageal atresia (EA), although a rare congenital anomaly, represents one of the most common gastrointestinal birth defects. There is a gap in our knowledge regarding the impact of perioperative critical care in infants born with EA. This study addresses EA types, disease severity stratification, and mortality in a retrospective cohort at a single institution. Institutional Review Board approved our retrospective cross-sectional study of term-born (n = 53) and premature infants (28–37 weeks of gestation; n = 31) that underwent primary surgical repair of EA at a single institution from 2009–2020. Demographic and clinical data were obtained from the electronic medical record, Powerchart (Cerner, London, UK). Patients were categorized by (i) sex, (ii) gestational age at birth, (iii) types of EA (in relation to respiratory tract anomalies), (iv) co-occurring congenital anomalies, (v) severity of disease (viz. American Society of Anesthesiologists (ASA) and Pediatric Risk Assessment (PRAm) scores), (vi) type of surgical repair for EA (primary anastomosis vs. Foker process), and (vii) survival rate classification using Spitz and Waterston scores. Data were presented as numerical sums and percentages. The frequency of anatomical types of EA in our cohort parallels that of the literature: 9.5% (8/84) type A, 9.5% (8/84) type B, 80% (67/84) type C, and 1% (1/84) type D. Long-gap EA accounts for 88% (7/8) type A, 75% (6/8) type B, and 13% (9/67) type C in the cohort studied. Our novel results show a nearly equal distribution of sex per each EA type, and gestational age (term-born vs. premature) by anatomical EA type. PRAm scoring showed a wider range of disease severity (3–9) than ASA scores (III and IV). The survival rate in our EA cohort dramatically increased in comparison to the literature in previous decades. This retrospective analysis at a single institution shows incidence of EA per sex and gestational status for anatomical types (EA type A-D) and by surgical approach (primary anastomosis vs. Foker process for short-gap vs. long-gap EA, respectively). Despite its wider range, PRAm score was not more useful in predicting disease severity in comparison to ASA score. Increased survival rates over the last decade suggest a potential need to assess unique operative and perioperative risks in this unique population of patients. Presented findings also represent a foundation for future clinical studies of outcomes in infants born with EA.

Genetic Counseling and Diagnostics in Anorectal Malformation

Anorectal malformation (ARM) is a relatively frequently occurring congenital anomaly of hindgut development with a prevalence of 1 in 3,000 live births. ARM may present as an isolated anomaly, but it can also be associated with other anomalies, sometimes as part of a recognizable syndrome. After birth, much medical attention is given to the treatment and restoring of bowel function in children with ARM. Effort should also be given to studying the etiology of the ARM in these patients. This information is important to both the medical community and the family, because it can help guide treatment and provides information on the long-term prognosis of the patient and recurrence risk in the family.In this article, we will review the current knowledge on the (genetic) etiology of (syndromic) ARM and provide guidelines for (family) history taking and clinical and genetic studies of ARM patients and their families, which is needed to study the causal factors in an ARM patient and for genetic counseling of the families.

Mice lacking DYRK2 exhibit congenital malformations with lung hypoplasia and altered Foxf1 expression gradient

Congenital malformations cause life-threatening diseases in pediatrics, yet the molecular mechanism of organogenesis is poorly understood. Here we show that Dyrk2-deficient mice display congenital malformations in multiple organs. Transcriptome analysis reveals molecular pathology of Dyrk2-deficient mice, particularly with respect to Foxf1 reduction. Mutant pups exhibit sudden death soon after birth due to respiratory failure. Detailed analyses of primordial lungs at the early developmental stage demonstrate that Dyrk2 deficiency leads to altered airway branching and insufficient alveolar development. Furthermore, the Foxf1 expression gradient in mutant lung mesenchyme is disrupted, reducing Foxf1 target genes, which are necessary for proper airway and alveolar development. In ex vivo lung culture system, we rescue the expression of Foxf1 and its target genes in Dyrk2-deficient lung by restoring Shh signaling activity. Taken together, we demonstrate that Dyrk2 is essential for embryogenesis and its disruption results in congenital malformation.

Esophageal atresia/tracheoesophageal fistula and proximal symphalangism in a patient with a NOG nonsense mutation

Esophageal atresia and tracheoesophageal fistula (EA/TEF) are relatively common malformations of the human foregut. The etiology remains incompletely understood with genetic causes identified in a small minority of affected patients. We present the case of a newborn with type C EA/TEF along with proximal symphalangism found to have a de novo NOG nonsense mutation. Patients with chromosome 17q deletions including the NOG gene have previously been reported to have EA/TEF but mutations in the gene have not been identified in patients with this malformation. This case provides evidence that haploinsufficiency for NOG may be the cause for EA/TEF in the 17q deletion syndrome and suggests that the clinical spectrum of NOG-related symphalangism spectrum disorders may include EA/TEF.

Renal agenesis-related genes are associated with Herlyn-Werner-Wunderlich syndrome

OBJECTIVE

To explore the genetic causes of Herlyn-Werner-Wunderlich syndrome (HWWS) using whole-exome sequencing.

DESIGN

Retrospective genetic study.

SETTING

Academic medical center.

PATIENT(S)

Twelve patients with HWWS.

INTERVENTION(S)

Whole-exome sequencing was performed for each patient. Sanger sequencing was used to confirm the potential causative genetic variants. In silico analysis and American College of Medical Genetics and Genomics guidelines were used to classify the pathogenicity of each variant.

MAIN OUTCOME MEASURE(S)

Rare sequence variants associated with müllerian duct development and renal agenesis were identified and included in subsequent analyses.

RESULT(S)

A total of 11 variants were identified in 10 of 12 patients (83.3%) and were considered to constitute a molecular genetic diagnosis of HWWS. These 11 variants were related to 9 genes: CHD1L, TRIM32, TGFBR3, WNT4, RET, FRAS1, FAT1, FOXF1, and PCSK5. All variants were heterozygous and confirmed by Sanger sequencing. The changes included one frameshift variant, one splice-site variant, and eight missense variants. All of the identified variants were absent or rare in Genome Aggregation Database East Asian populations. One of the 11 variants (9.1%) was classified as a pathogenic variant according to the American College of Medical Genetics and Genomics guidelines, and 8 of the 11 variants (72.7%) were classified as variants of uncertain significance.

CONCLUSION(S)

To our knowledge, this is the first report of the genetic causes of HWWS. Renal agenesis-related genes, such as CHD1L, TRIM32, RET, and WNT4, may be associated with HWWS. Identification of these variants can not only help us understand the etiology of HWWS and the relationship between reproductive tract development and urinary system development, but additionally improve the level of genetic counseling for HWWS.

Transcriptomics unravels molecular players shaping dorsal lip hypertrophy in the vacuum cleaner cichlid, Gnathochromis permaxillaris

BACKGROUND

Teleosts display a spectacular diversity of craniofacial adaptations that often mediates ecological specializations. A considerable amount of research has revealed molecular players underlying skeletal craniofacial morphologies, but less is known about soft craniofacial phenotypes. Here we focus on an example of lip hypertrophy in the benthivorous Lake Tangnayika cichlid, Gnathochromis permaxillaris, considered to be a morphological adaptation to extract invertebrates out of the uppermost layer of mud bottom. We investigate the molecular and regulatory basis of lip hypertrophy in G. permaxillaris using a comparative transcriptomic approach.

RESULTS

We identified a gene regulatory network involved in tissue overgrowth and cellular hypertrophy, potentially associated with the formation of a locally restricted hypertrophic lip in a teleost fish species. Of particular interest were the increased expression level of apoda and fhl2, as well as reduced expression of cyp1a, gimap8, lama5 and rasal3, in the hypertrophic lip region which have been implicated in lip formation in other vertebrates. Among the predicted upstream transcription factors, we found reduced expression of foxp1 in the hypertrophic lip region, which is known to act as repressor of cell growth and proliferation, and its function has been associated with hypertrophy of upper lip in human.

CONCLUSION

Our results provide a genetic foundation for future studies of molecular players shaping soft and exaggerated, but locally restricted, craniofacial morphological changes in fish and perhaps across vertebrates. In the future, we advocate integrating gene regulatory networks of various craniofacial phenotypes to understand how they collectively govern trophic and behavioural adaptations.

Forkhead box F1 induces columnar phenotype and epithelial-to-mesenchymal transition in esophageal squamous cells to initiate Barrett's like metaplasia

Multiple genome-wide association studies (GWAS) have linked Forkhead Box F1 (FOXF1) to Barrett's esophagus (BE). Understanding whether FOXF1 is involved in initiation of Barrett's metaplasia could allow FOXF1 to be used for risk stratification and for therapy. Two-dimensional cell cultures and three-dimensional organoid cultures and well-annotated human biopsies were used to determine the role of FOXF1 in BE pathogenesis. Multiple established esophageal squamous and BE cell lines were tested in gain- and loss-of-function studies. Initiation of a BE-like metaplastic change was evaluated by measuring characteristic cytokeratins and global gene expression profiling and by culturing organoids. Epithelial-mesenchymal transition (EMT) was evaluated by immunostaining for E-cadherin, vimentin and Snail, and by cell motility assay. Columnar esophageal epithelium of BE patients exhibited higher expression of FOXF1 compared to normal squamous esophageal epithelium of GERD patients (P < 0.001). Acidic bile salts induced nuclear FOXF1 in esophageal squamous cells. FOXF1 overexpression in normal esophageal squamous cells: (a) increased columnar cytokeratins and decreased squamous cytokeratins, (b) converted squamous organoids to glandular organoids, and (c) switched global gene profiles to resemble that of human BE epithelium (P = 2.1685e - 06 for upregulated genes and P = 8.3378e - 09 for downregulated genes). FOXF1 inhibition in BE cell lines led to loss of BE differentiation markers, CK7, and mucin 2. Also, FOXF1 induced EMT and promoted cell motility in normal esophageal squamous epithelial cells. FOXF1-induced genes mapped to pathways such as Cancer, Cellular Assembly and Organization, DNA Replication, Recombination, and Repair. In conclusion, FOXF1 promotes a BE-like columnar phenotype and cell motility in esophageal squamous epithelial cells, which may have a critical role in BE development. FOXF1 should be studied further as a biomarker for BE and as a target for BE treatment.

Delayed Diagnosis in Esophageal Atresia and Tracheoesophageal Fistula: Case Study

BACKGROUND

Timely identification of esophageal atresia is challenging. Diagnosis may be suspected antenatally with a combination of polyhydramnios, associated with a small or absent stomach bubble or other anomalies. Esophageal atresia can be suspected postnatally in the presence of tachypnea, increased oral secretions, and an inability to advance an orogastric tube. Failure to recognize an esophageal atresia can have life-threatening implications.

CLINICAL FINDINGS

A 5-day-old infant with a history of failure to thrive and respiratory distress presented in a community emergency department following a prolonged apnea associated with a breastfeed.

PRIMARY DIAGNOSIS

Delayed postnatal diagnosis of esophageal atresia and tracheoesophageal fistula.

INTERVENTIONS

During stabilization in the emergency department, a nasogastric tube was placed to decompress the stomach. A subsequent chest and abdominal radiograph identified the nasogastric tube curled in the upper esophagus, confirming an esophageal atresia. The abdominal radiograph demonstrated gaseous distension, suggesting the presence of a distal tracheoesophageal fistula.

OUTCOMES

The neonate had a primary esophageal anastomosis and fistula ligation in a surgical neonatal unit. He was discharged home at 29 days of life.

PRACTICE RECOMMENDATIONS

Understanding the challenges of an antenatal diagnosis and awareness of postnatal presentation with a view to improving postnatal recognition and better-quality outcomes for infants with an esophageal atresia and tracheoesophageal fistula.

Phenotypic Characteristics and Copy Number Variants in a Cohort of Colombian Patients with VACTERL Association

VACTERL association (OMIM 192350) is a heterogeneous clinical condition characterized by congenital structural defects that include at least 3 of the following features: vertebral abnormalities, anal atresia, heart defects, tracheoesophageal fistula, renal malformations, and limb defects. The nonrandom occurrence of these malformations and some familial cases suggest a possible association with genetic factors such as chromosomal alterations, gene mutations, and inherited syndromes such as Fanconi anemia (FA). In this study, the clinical phenotype and its relationship with the presence of chromosomal abnormalities and FA were evaluated in 18 patients with VACTERL association. For this, a G-banded karyotype, array-comparative genomic hybridization, and chromosomal fragility test for FA were performed. All patients (10 female and 8 male) showed a broad clinical spectrum: 13 (72.2%) had vertebral abnormalities, 8 (44.4%) had anal atresia, 14 (77.8%) had heart defects, 8 (44.4%) had esophageal atresia, 10 (55.6%) had renal abnormalities, and 10 (55.6%) had limb defects. Chromosomal abnormalities and FA were ruled out. In 2 cases, the finding of microalterations, namely del(15)(q11.2) and dup(17)(q12), explained the phenotype; in 8 cases, copy number variations were classified as variants of unknown significance and as not yet described in VACTERL. These variants comprise genes related to important cellular functions and embryonic development.

Novel candidate genes in esophageal atresia/tracheoesophageal fistula identified by exome sequencing

The various malformations of the aerodigestive tract collectively known as esophageal atresia/tracheoesophageal fistula (EA/TEF) constitute a rare group of birth defects of largely unknown etiology. Previous studies have identified a small number of rare genetic variants causing syndromes associated with EA/TEF. We performed a pilot exome sequencing study of 45 unrelated simplex trios (probands and parents) with EA/TEF. Thirteen had isolated and 32 had nonisolated EA/TEF; none had a family history of EA/TEF. We identified de novo variants in protein-coding regions, including 19 missense variants predicted to be deleterious (D-mis) and 3 likely gene-disrupting (LGD) variants. Consistent with previous studies of structural birth defects, there is a trend of increased burden of de novo D-mis in cases (1.57-fold increase over the background mutation rate), and the burden is greater in constrained genes (2.55-fold, p = 0.003). There is a frameshift de novo variant in EFTUD2, a known EA/TEF risk gene involved in mRNA splicing. Strikingly, 15 out of 19 de novo D-mis variants are located in genes that are putative target genes of EFTUD2 or SOX2 (another known EA/TEF gene), much greater than expected by chance (3.34-fold, p value = 7.20e-5). We estimated that 33% of patients can be attributed to de novo deleterious variants in known and novel genes. We identified APC2, AMER3, PCDH1, GTF3C1, POLR2B, RAB3GAP2, and ITSN1 as plausible candidate genes in the etiology of EA/TEF. We conclude that further genomic analysis to identify de novo variants will likely identify previously undescribed genetic causes of EA/TEF.

Congenital microgastria-limb reduction association: A case report and review of the literature

We report a patient with phenotypic semblance to the congenital microgastria-limb reduction association (MLRD). Our patient presented with microgastria, bilateral upper limb anomalies, asplenia, solitary kidney, and mild micrognathia. In addition to the anomalies seen in our patient, MLRD has been associated with respiratory, cardiovascular, and central nervous system anomalies. MLRD is thought to arise from a developmental field defect during embryonic weeks five and six; however, no genetic cause has been elucidated. Along with our patient presentation, we review the literature to further our understanding of the MLRD phenotype spectrum.

Genotype-phenotype correlation in two Polish neonates with alveolar capillary dysplasia

BACKGROUND

Alveolar capillary dysplasia (ACD) is a rare cause of severe pulmonary hypertension and respiratory failure in neonates. The onset of ACD is usually preceded by a short asymptomatic period. The condition is refractory to all available therapies as it irreversibly affects development of the capillary bed in the lungs. The diagnosis of ACD is based on histopathological evaluation of lung biopsy or autopsy tissue or genetic testing of FOXF1 on chromosome 16q24.1. Here, we describe the first two Polish patients with ACD confirmed by histopathological and genetic examination.

CASE PRESENTATION

The patients were term neonates with high Apgar scores in the first minutes of life. They both were diagnosed prenatally with heart defects. Additionally, the first patient presented with omphalocele. The neonate slightly deteriorated around 12th hour of life, but underwent surgical repair of omphalocele followed by mechanical ventilation. Due to further deterioration, therapy included inhaled nitric oxide (iNO), inotropes and surfactant administration. The second patient was treated with prostaglandin E1 since birth due to suspicion of aortic coarctation (CoA). After ruling out CoA in the 3rd day of life, infusion of prostaglandin E1 was discountinued and immediately patient's condition worsened. Subsequent treatment included re-administration of prostaglandin E1, iNO and mechanical ventilation. Both patients presented with transient improvement after application of iNO, but died despite maximized therapy. They were histopathologically diagnosed post-mortem with ACD. Array comparative genomic hybridization in patient one and patient two revealed copy-number variant (CNV) deletions, respectively, ~ 1.45 Mb in size involving FOXF1 and an ~ 0.7 Mb in size involving FOXF1 enhancer and leaving FOXF1 intact.

CONCLUSIONS

Both patients presented with a distinct course of ACD, extra-pulmonary manifestations and response to medications. Surgery and ceasing of prostaglandin E1 infusion should be considered as potential causes of this variability. We further highlight the necessity of thorough genetic testing and histopathological examination and propose immunostaining for CD31 and CD34 to facilitate the diagnostic process for better management of infants with ACD.

Oesophageal atresia

Oesophageal atresia (EA) is a congenital abnormality of the oesophagus that is caused by incomplete embryonic compartmentalization of the foregut. EA commonly occurs with a tracheo-oesophageal fistula (TEF). Associated birth defects or anomalies, such as VACTERL association, trisomy 18 or 21 and CHARGE syndrome, occur in the majority of patients born with EA. Although several studies have revealed signalling pathways and genes potentially involved in the development of EA, our understanding of the pathophysiology of EA lags behind the improvements in surgical and clinical care of patients born with this anomaly. EA is treated surgically to restore the oesophageal interruption and, if present, ligate and divide the TEF. Survival is now ~90% in those born with EA with severe associated anomalies and even higher in those born with EA alone. Despite these achievements, long-term gastrointestinal and respiratory complications and comorbidities in patients born with EA are common and lead to decreased quality of life. Oesophageal motility disorders are probably ubiquitous in patients after undergoing EA repair and often underlie these complications and comorbidities. The implementation of several new diagnostic and screening tools in clinical care, including high-resolution impedance manometry, pH-multichannel intraluminal impedance testing and disease-specific quality of life questionnaires now provide better insight into these problems and may contribute to better long-term outcomes in the future.

Eosinophilic Esophagitis in Esophageal Atresia

Recent studies have reported a higher prevalence of eosinophilic esophagitis in children with esophageal atresia. Under recognition of eosinophilic esophagitis in these patients may lead to excessive use of antireflux therapy and an escalation of interventions, including fundoplication, as symptoms may be attributed to gastroesophageal reflux disease. In addition, long-term untreated eosinophilic esophagitis may lead to recurrent strictures due to transmural esophageal inflammation, necessitating repeated dilatations. Eosinophilic esophagitis should be considered when children with esophageal atresia show persistent symptoms on standard antireflux treatment, increasing dysphagia, and recurrent strictures. Treatment has been found to not only significantly reduce intraepithelial eosinophil count, but also to improve symptoms, and to lower the occurrence of strictures and the need for dilatations. Future prospective studies are warranted in this area.

Copy number variations of MTHFSD gene across pig breeds and its association with litter size traits in Chinese indigenous Xiang pig

Copy number variation (CNV) is a major proportion of genetic variation, which changes the gene structure and dosage and affects gene expression and function. To validate the presence and the function of CNV in pig, we used real-time quantitative polymerase chain reaction (qPCR) method to validate a 496 kb CNV region comprising MTHFSD gene on chromosome 6 of Xiang pig detected by single nucleotide polymorphism (SNP) array. Then we investigated the distribution of the MTHFSD CNV in a total of 545 pigs in four breeds. About 46.2% and 32.7% individuals in the four pig breeds were detected to be types of loss and gain of MTHFSD locus. The relative copy numbers of MTHFSD gene showed the largest variation range (0-55 copies) in the Xiang pig population. The copy numbers of MTHFSD gene presented the positive correlations with the transcript level of MTHFSD gene in adult ovaries. Statistical analysis indicated that CNVs of MTHFSD gene was significantly changed the litter size traits of Xiang pigs, and the individuals with CNV gain showed more litter size than the CNV loss pigs. We have reasons to believe that the MTHFSD as RNA-binding protein play an important role in pig reproduction as a result of regulating MTHFS mRNA metabolism.

Atrioventricular canal defect and genetic syndromes: The unifying role of sonic hedgehog

The atrioventricular canal defect (AVCD) is a congenital heart defect (CHD) frequently associated with extracardiac anomalies (75%). Previous observations from a personal series of patients with AVCD and "polydactyly syndromes" showed that the distinct morphology and combination of AVCD features in some of these syndromes is reminiscent of the cardiac phenotype found in heterotaxy, a malformation complex previously associated with functional cilia abnormalities and aberrant Hedgehog (Hh) signaling. Hh signaling coordinates multiple aspects of left-right lateralization and cardiovascular growth. Being active at the venous pole the secondary heart field (SHF) is essential for normal development of dorsal mesenchymal protrusion and AVCD formation and septation. Experimental data show that perturbations of different components of the Hh pathway can lead to developmental errors presenting with partially overlapping manifestations and AVCD as a common denominator. We review the potential role of Hh signaling in the pathogenesis of AVCD in different genetic disorders. AVCD can be viewed as part of a "developmental field," according to the concept that malformations can be due to defects in signal transduction cascades or pathways, as morphogenetic units which may be altered by Mendelian mutations, aneuploidies, and environmental causes.

Experience with genomic sequencing in pediatric patients with congenital cardiac defects in a large community hospital

BACKGROUND

Congenital cardiac defects, whether isolated or as part of a larger syndrome, are the most common type of human birth defect occurring on average in about 1% of live births depending on the malformation. As there is an expanding understanding of the underlying molecular mechanisms by which a cardiac defect may occur, there is a need to assess the current rates of diagnosis of cardiac defects by molecular sequencing in a clinical setting.

METHODS AND RESULTS

In this report, we evaluated 34 neonatal and pediatric patients born with a cardiac defect and their parents using exomized preexisting whole genome sequencing (WGS) data to model clinically available exon-based tests. Overall, we identified candidate variants in previously reported cardiac-related genes in 35% (12/34) of the probands. These include clearly pathogenic variants in two of 34 patients (6%) and variants of uncertain significance in relevant genes in 10 patients (26%), of these latter 10, 2 segregated with clinically apparent findings in the family trios.

CONCLUSIONS

These findings suggest that with current knowledge of the proteins underlying CHD, genomic sequencing can identify the underlying genetic etiology in certain patients; however, this technology currently does not have a high enough yield to be of routine clinical use in the screening of pediatric congenital cardiac defects.

Surveillance in Patients With Esophageal Atresia/Tracheoesophageal Fistula

PURPOSE OF REVIEW

Esophageal atresia/tracheoesophageal fistula (EA/TEF) is a congenital aerodigestive anomaly with high survival rates after surgical repair. Care should now be focused on prevention of long-term complications using appropriate surveillance techniques.

RECENT FINDINGS

The incidence of gastroesophageal reflux disease (GERD) is high in patients with EA/TEF. Consequences of untreated GERD include esophagitis, strictures, and Barrett esophagus. Subjective symptoms are an unreliable indicator of presence or severity of GERD, and therefore, diagnostic testing is needed to assess esophageal heath and monitor the effectiveness of anti-reflux treatment. Esophagogastroduodenoscopy with biopsy remains the primary surveillance tool, but is invasive and not without risks. Less-invasive modalities such as multichannel intraluminal impedance and pH monitoring to assess GERD appear to correlate strongly with esophageal histology and may provide sufficient information to guide treatment. EA/TEF patients face numerous challenges that need to be considered. Routine surveillance protocols and close monitoring are warranted to assess complications. Further research is needed to delineate the frequency of esophagogastroduodenoscopy versus less-invasive and promising modalities such as multichannel intraluminal impedance-pH monitoring.

Motility, digestive and nutritional problems in Esophageal Atresia

Esophageal atresia (EA) with or without tracheoesophageal fistula (TEF) is a rare congenital malformation. Digestive and nutritional problems remain frequent in children with EA both in early infancy and at long-term follow-up. These patients are at major risk of presenting with gastroesophageal reflux and its complications, such as anastomotic strictures. Esophageal dysmotility is constant, and can have important consequences on feeding and nutritional status. Patients with EA need a systematic follow-up with a multidisciplinary team.

Rhinocerebral zygomycosis: an unusual dramatic presentation in a paediatric cardiac patient without risk factors

Mucormycosis is an angioinvasive infection caused by ubiquitous filamentous fungi of the order Mucorales. We describe a case of rhinocerebral mucormycosis presented in a paediatric patient after cardiac surgery correction of a complete atrioventricular canal defect. The rhinocerebral form of mucormycosis in our patient presented as an important epistaxis that needed immediate intubation due to blood inhalation. Furthermore, due to the worsening of pulmonary function, the patient also needed mechanical support with veno-arterial extracorporeal membrane oxygenation. The patient died as a consequence of a disseminated form of fungal infection. We describe our experience of this rare opportunistic infection and we think that early recognition of the disease could help in proper management.

The genetic landscape and clinical implications of vertebral anomalies in VACTERL association

VACTERL association is a condition comprising multisystem congenital malformations, causing severe physical disability in affected individuals. It is typically defined by the concurrence of at least three of the following component features: vertebral anomalies (V), anal atresia (A), cardiac malformations (C), tracheo-oesophageal fistula (TE), renal dysplasia (R) and limb abnormalities (L). Vertebral anomaly is one of the most important and common defects that has been reported in approximately 60–95% of all VACTERL patients. Recent breakthroughs have suggested that genetic factors play an important role in VACTERL association, especially in those with vertebral phenotypes. In this review, we summarised the genetic studies of the VACTERL association, especially focusing on the genetic aetiology of patients with vertebral anomalies. Furthermore, genetic reports of other syndromes with vertebral phenotypes overlapping with VACTERL association are also included. We aim to provide a further understanding of the genetic aetiology and a better evidence for genetic diagnosis of the association and vertebral anomalies.

Respiratory Care of Infants and Children with Congenital Tracheo-Oesophageal Fistula and Oesophageal Atresia

Despite acute respiratory and chronic respiratory and gastro-intestinal complications, most infants and children with a history of oesophageal atresia / trachea-oesophageal fistula [OA/TOF] can expect to live a fairly normal life. Close multidisciplinary medical and surgical follow-up can identify important co-morbidities whose treatment can improve symptoms and optimize pulmonary and nutritional outcomes. This article will discuss the aetiology, classification, diagnosis and treatment of congenital TOF, with an emphasis on post-surgical respiratory management, recognition of early and late onset complications, and long-term clinical outcomes.

Fetal Magnetic Resonance Imaging of Malformations Associated with Heterotaxy

Magnetic resonance imaging (MRI) is increasingly used as an investigation during fetal life, particularly for assessment of intracranial masses, congenital diaphragmatic hernia, myelomeningocele, and abdominal masses. As the number of scans increases, so is the variety of congenital malformations being recognized. It is axiomatic that interpretation of the findings is enhanced when attention is paid to the likely findings in the setting of known syndromes, this information then dictating the need for additional acquisition of images. One such syndrome is so-called "visceral heterotaxy", in which there is typically an isomeric, rather than a lateralized, arrangement of the thoracic and abdominal organs. Typically associated with complex congenital cardiac malformations, heterotaxy can also involve the central nervous system, and produce pulmonary, gastrointestinal, immunologic, and genitourinary malformations. In this review, we discuss how these findings can be demonstrated using fetal MRI.

Polymorphisms near TBX5 and GDF7 are associated with increased risk for Barrett's esophagus

BACKGROUND & AIMS

Barrett's esophagus (BE) increases the risk of esophageal adenocarcinoma (EAC). We found the risk to be BE has been associated with single nucleotide polymorphisms (SNPs) on chromosome 6p21 (within the HLA region) and on 16q23, where the closest protein-coding gene is FOXF1. Subsequently, the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON) identified risk loci for BE and esophageal adenocarcinoma near CRTC1 and BARX1, and within 100 kb of FOXP1. We aimed to identify further SNPs that increased BE risk and to validate previously reported associations.

METHODS

We performed a genome-wide association study (GWAS) to identify variants associated with BE and further analyzed promising variants identified by BEACON by genotyping 10,158 patients with BE and 21,062 controls.

RESULTS

We identified 2 SNPs not previously associated with BE: rs3072 (2p24.1; odds ratio [OR] = 1.14; 95% CI: 1.09-1.18; P = 1.8 × 10(-11)) and rs2701108 (12q24.21; OR = 0.90; 95% CI: 0.86-0.93; P = 7.5 × 10(-9)). The closest protein-coding genes were respectively GDF7 (rs3072), which encodes a ligand in the bone morphogenetic protein pathway, and TBX5 (rs2701108), which encodes a transcription factor that regulates esophageal and cardiac development. Our data also supported in BE cases 3 risk SNPs identified by BEACON (rs2687201, rs11789015, and rs10423674). Meta-analysis of all data identified another SNP associated with BE and esophageal adenocarcinoma: rs3784262, within ALDH1A2 (OR = 0.90; 95% CI: 0.87-0.93; P = 3.72 × 10(-9)).

CONCLUSIONS

We identified 2 loci associated with risk of BE and provided data to support a further locus. The genes we found to be associated with risk for BE encode transcription factors involved in thoracic, diaphragmatic, and esophageal development or proteins involved in the inflammatory response.

Results from the French National Esophageal Atresia register: one-year outcome

Background

The aim of the present national prospective population-based study was to assess the early morbidity of esophageal atresia (EA).

Methods

All 38 multidisciplinary French centers that care for patients with EA returned a specific questionnaire about the 1-year outcome for each patient. This information was centralized, checked, and entered into a database.

Results

From the total population of 307 EA patients born in 2008 and 2009, data about the 1-year outcome were obtained from 301 (98%) patients, of whom 4% were lost to follow-up and 5% died. Medical complications occurred in 34% of the patients: anastomotic leaks (8%), recurrent tracheoesophageal fistula (4%), and anastomotic stenosis (22%); all of the latter group needed dilation (median, 2 dilations/patient). A new hospitalization was required for 59% of patients (2.5 hospitalizations/patient) for digestive (52%) or respiratory (48%) reasons. Twelve percent of patients required antireflux surgery at a median age of 164 days (range, 33–398 days), and 1% underwent an aortopexy for severe tracheomalacia. The weight/age Z-score was −0.8 (range, −5.5 to 3.7 months) at 12 months. Fifteen percent of patients were undernourished at 12 months of age, whereas 37% presented with respiratory symptoms and 15% had dysphagia at the last follow-up. Significant independent factors associated with medical complications were anastomotic esophageal tension (p = .0009) and presence of a gastrostomy (p = .0002); exclusive oral feeding at discharge was associated with a decreased risk of complications (p = .007).

Conclusions

Digestive and respiratory morbidities remain frequent during the first year of life and are associated with difficult anastomosis and lack of full oral feeding.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-014-0206-5) contains supplementary material, which is available to authorized users.

One shall become two: Separation of the esophagus and trachea from the common foregut tube

The alimentary and respiratory organ systems arise from a common endodermal origin, the anterior foregut tube. Formation of the esophagus from the dorsal region and the trachea from the ventral region of the foregut primordium occurs by means of a poorly understood compartmentalization process. Disruption of this process can result in severe birth defects, such as esophageal atresia and tracheo-esphageal fistula (EA/TEF), in which the lumina of the trachea and esophagus remain connected. Here we summarize the signaling networks known to be necessary for regulating dorsoventral patterning within the common foregut tube and cellular behaviors that may occur during normal foregut compartmentalization. We propose that dorsoventral patterning serves to establish a lateral region of the foregut tube that is capable of undergoing specialized cellular rearrangements, culminating in compartmentalization. We review established as well as new rodent models that may be useful in addressing this hypothesis. Finally, we discuss new experimental models that could help elucidate the mechanism behind foregut compartmentalization. An integrated approach to future foregut morphogenesis research will allow for a better understanding of this complex process.

Oesophageal atresia and tracheo-oesophageal fistula

Oesophageal atresia with tracheo-oesophageal fistula is a relatively common congenital anomaly occurring in around 1:2500 births. The aetiology and embryology of the condition remain unclear, whilst associations with other significant anomalies are common. Studies in rodent models are contributing to our understanding of the condition. Advances in surgical care and neonatal management have improved survival considerably to around 90%. Long-gap and isolated oesophageal atresia present significant management challenges. Post-operative and long-term complications including oesophageal stricture, gastro-oesophageal reflux and respiratory compromise however remain relatively common and continue to pose a challenge for the ongoing management of patients.

Genome-wide association study of maternal and inherited effects on left-sided cardiac malformations

Congenital left-sided lesions (LSLs) are serious, heritable malformations of the heart. However, little is known about the genetic causes of LSLs. This study was undertaken to identify common variants acting through the genotype of the affected individual (i.e. case) or the mother (e.g. via an in utero effect) that influence the risk of LSLs. A genome-wide association study (GWAS) was performed using data from 377 LSL case-parent triads, with follow-up studies in an independent sample of 224 triads and analysis of the combined data. Associations with both the case and maternal genotypes were assessed using log-linear analyses under an additive model. An association between LSLs and the case genotype for one intergenic SNP on chromosome 16 achieved genome-wide significance in the combined data (rs8061121, combined P = 4.0 × 10(-9); relative risk to heterozygote: 2.6, 95% CI: 1.9-3.7). In the combined data, there was also suggestive evidence of association between LSLs and the case genotype for a variant in the synaptoporin gene (rs1975649, combined P = 3.4 × 10(-7); relative risk to heterozygote: 1.6, 95% CI: 1.4-2.0) and between LSLs and the maternal genotype for an intergenic SNP on chromosome 10 (rs11008222, combined P = 6.3 × 10(-7); relative risk to heterozygote: 1.6, 95% CI: 1.4-2.0). This is the first GWAS of LSLs to evaluate associations with both the case and maternal genotypes. The results of this study identify three candidate LSL susceptibility loci, including one that appears to be associated with the risk of LSLs via the maternal genotype.

Eosinophilic esophagitis in children with esophageal atresia

Eosinophilic esophagitis (EoE) has only rarely been reported in esophageal atresia (EA) patients. A retrospective case analysis of all EA patients born at our center between January 1999 and April 2012 was performed. A total of 113 of patients were identified; 10 patients were excluded as a result of inadequate data. Eighteen patients (17%) were diagnosed with EoE. The average number of eosinophilis was 30/high-power field (HPF) (19/HPF-80/HPF). The median age for diagnosis of EoE was 1 year and 6 months (8 months-8 years and 7 months). Children with EoE had a significantly greater incidence of reflux symptoms, dysphagia, tracheomalacia, and 'hypoxic spells' (P < 0.05). EoE patients also underwent significantly more surgery including fundoplication and aortopexy when compared with those without EoE (P < 0.0001). Although the incidence of gastrostomy was greater in the EoE group (33% vs. 13%), this was not statistically significant. Half of the EoE patients had a coexisting atopic condition at time of diagnosis. The commonest condition was asthma 7/18 (38%) followed by specific food allergy 6/18 (33%). EoE was treated in 11 patients with either swallowed fluticasone or budesonide slurry. All improved clinically. Histologically, five had complete resolution and six had partial improvement. Six children with EoE were treated with acid suppression alone. All improved clinically, and 5/6 had subsequent histological resolution. One child who received acid suppression and an exclusion diet also improved. Seven patients (38%) had an esophageal stricture at time of EoE diagnosis. Five were dilated at time of the initial endoscopy, prior to the diagnosis of EoE being available. Two patients had resolution of their strictures on medical treatment of their EoE alone and did not require further dilatation. EoE was seen in 17% of children with EA in this study. EoE should be considered in EA patients with persistent symptoms on standard reflux treatment, increasing dysphagia, and recurrent strictures.

Alveolar capillary dysplasia with multiple congenital anomalies and bronchoscopic airway abnormalities

Alveolar capillary dysplasia is a rare and fatal disease of newborn infants. Here we describe a patient with alveolar capillary dysplasia, multiple congenital anomalies, a novel genetic mutation and previously undocumented airway findings on bronchoscopy. Knowledge of these associations may help diagnose this rare disorder in neonates with hypoxemic respiratory failure.

Structural and numerical changes of chromosome X in patients with esophageal atresia

Esophageal atresia with or without tracheoesophageal fistula (EA/TEF) is a relatively common birth defect often associated with additional congenital anomalies such as vertebral, anal, cardiovascular, renal and limb defects, the so-called VACTERL association. Yet, little is known about the causal genetic factors. Rare case reports of gastrointestinal anomalies in children with triple X syndrome prompted us to survey the incidence of structural and numerical changes of chromosome X in patients with EA/TEF. All available (n=269) karyotypes of our large (321) EA/TEF patient cohort were evaluated for X-chromosome anomalies. If sufficient DNA material was available, we determined genome-wide copy number profiles with SNP array and identified subtelomeric aberrations on the difficult to profile PAR1 region using telomere-multiplex ligation-dependent probe amplification. In addition, we investigated X-chromosome inactivation (XCI) patterns and mode of inheritance of detected aberrations in selected patients. Three EA/TEF patients had an additional maternally inherited X chromosome. These three female patients had normal random XCI patterns. Two male EA/TEF patients had small inherited duplications of the XY-linked SHOX (Short stature HOmeoboX-containing) locus. Patients were small for gestational age at birth (<P5) and had additional, mostly VACTERL associated, anomalies. Triple X syndrome is rarely described in patients with EA/TEF and no duplications of the SHOX gene were reported so far in these patients. As normal patterns of XCI were seen, overexpression of X-linked genes that escape XCI, such as the SHOX gene, could be pathogenic by disturbing developmental pathways.

TACRD and VACTERL associations in a fetus: case report and review of the literature

Tracheal agenesis is a rare and potentially lethal congenital anomaly. The incidence is less than 1/50,000, with a male:female ratio of 2:1. We report the case of a male fetus with complete agenesis of the trachea and a tracheoesophageal fistula arising from the esophagus that connected through the carina, as well as several abnormalities (congenital cardiac abnormalities, duodenal atresia, vertebral defects, anal atresia, renal defects, limb defects, and diaphragmatic hernia). To our knowledge, few cases of infants with VACTERL or TACRD association have been reported to date. Here, we report a new case of a fetus that showed the full range of VACTERL and TACRD associations.

Forkhead transcription factor FOXF1 is a novel target gene of the p53 family and regulates cancer cell migration and invasiveness

p53 is an established tumor suppressor that can activate the transcription of multiple target genes. Recent evidence suggests that p53 may contribute to the regulation of cell invasion and migration. In this study, we show that the forkhead box transcription factor FOXF1 is a novel target of the p53 family because FOXF1 is upregulated by p53, TAp73 and TAp63. We show that FOXF1 is induced upon DNA damage in a p53-dependent manner. Furthermore, we identified a response element located within the FOXF1 gene that is responsive to wild-type p53, TAp73β and TAp63γ. The ectopic expression of FOXF1 inhibited cancer cell invasion and migration, whereas the inactivation of FOXF1 stimulated cell invasion and migration. We also show that FOXF1 regulates the transcriptional activity of E-cadherin (CDH1) by acting on its FOXF1 consensus binding site located upstream of the E-cadherin gene. Collectively, our results show that FOXF1 is a p53 family target gene, and our data suggest that FOXF1 and p53 form a portion of a regulatory transcriptional network that appears to have an important role in cancer cell invasion and migration.

Inhibition of Hedgehog signaling in the gastrointestinal tract: targeting the cancer microenvironment

This review summarizes emerging information regarding the Hedgehog (Hh) signaling pathway during neoplastic transformation in the gastrointestinal tract. Although there is a role for the well-established canonical pathway in which Hedgehog ligands interact with their receptor Patched, there is sufficient evidence that downstream components of the Hh pathway, e.g., Gli1, are hijacked by non-Hh signaling pathways to promote the conversion of the epithelium to dysplasia and carcinoma. We review the canonical pathway and involvement of primary cilia, and then focus on current evidence for Hh signaling in luminal bowel cancers as well as accessory organs, i.e., liver, pancreas and biliary ducts. We conclude that targeting the Hh pathway with small molecules, nutriceuticals and other mechanisms will likely require a combination of inhibitors that target Gli transcription factors in addition to canonical modulators such as Smoothened.

Esophageal atresia: data from a national cohort

PURPOSE

A prospective national register was established in 2008 to record all new cases of live-birth newborns with esophageal atresia (EA). This epidemiological survey was recommended as part of a national rare diseases plan.

METHODS

All 38 national centers treating EA participated by completing for each patient at first discharge a questionnaire validated by a national committee of experts. Data were centralized by the national reference center for esophageal anomalies. Quantitative and qualitative analyses were performed, with P-values of less than 0.05 considered statistically significant. Results of the 2008-2009 data collection are presented in this report.

RESULTS

Three hundred seven new living cases of EA were recorded between January 1, 2008, and December 31, 2009. The male/female sex ratio was 1.3, and the live-birth prevalence of EA was 1.8 per 10,000 births. Major characteristics were comparable to those reported in the literature. Survival was 95%, and no correlation with caseload was noted.

CONCLUSIONS

Epidemiologic surveys of congenital anomalies such as EA, which is a rare disease, provide valuable data for public health authorities and fulfill one important mission of reference centers. When compared with previous epidemiological data, this national population-based registry suggests that the incidence of EA remains stable.

Novel FOXF1 mutations in sporadic and familial cases of alveolar capillary dysplasia with misaligned pulmonary veins imply a role for its DNA binding domain

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare and lethal developmental disorder of the lung defined by a constellation of characteristic histopathological features. Nonpulmonary anomalies involving organs of gastrointestinal, cardiovascular, and genitourinary systems have been identified in approximately 80% of patients with ACD/MPV. We have collected DNA and pathological samples from more than 90 infants with ACD/MPV and their family members. Since the publication of our initial report of four point mutations and 10 deletions, we have identified an additional 38 novel nonsynonymous mutations of FOXF1 (nine nonsense, seven frameshift, one inframe deletion, 20 missense, and one no stop). This report represents an up to date list of all known FOXF1 mutations to the best of our knowledge. Majority of the cases are sporadic. We report four familial cases of which three show maternal inheritance, consistent with paternal imprinting of the gene. Twenty five mutations (60%) are located within the putative DNA-binding domain, indicating its plausible role in FOXF1 function. Five mutations map to the second exon. We identified two additional genic and eight genomic deletions upstream to FOXF1. These results corroborate and extend our previous observations and further establish involvement of FOXF1 in ACD/MPV and lung organogenesis.

Adriamycin-Induced Models of VACTERL Association

Animal models are of great importance for medical research. They have enabled analysis of the aetiology and pathogenesis of complex congenital malformations and have also led to major advances in the surgical and therapeutic management of these conditions. Animal models allow us to comprehend the morphological and molecular basis of disease and consequently to discover novel approaches for both surgical and medical therapy. The anthracycline antibiotic adriamycin was incidentally found to have teratogenic effects on rats, producing a range of defects remarkably similar to the VACTERL association of congenital anomalies in humans, providing a reproducible animal model of this condition. VACTERL association is a spectrum of birth defects which includes vertebral, anal, cardiovascular, tracheo-oesophageal, renal and limb anomalies. In recent years, adriamycin rodent models of VACTERL have provided valuable insights into the pathogenesis of this complex association, particularly in relation to tracheo-oesophageal malformations. The adriamycin rat model and adriamycin mouse model are now well established in the investigation of the morphology of faulty organogenesis and the regulation of gene expression in tracheo-oesophageal anomalies.

Considering the Embryopathogenesis of VACTERL Association

The nonrandom co-occurrence of vertebral, anorectal, cardiac, tracheoesophageal, genitourinary, and limb malformations, recognized as the VACTERL association, has not been satisfactorily explained from either a causation or embryopathogenesis standpoint. Few familial cases have been identified and maternal diabetes is the only environmental influence implicated to date. Mutations in single genes have been found in a number of syndromes with one or more of the VACTERL malformations, but these syndromes usually have other features which distinguish them from the VACTERL association. Animal models have provided clues to molecular pathways that may be involved in the embryogenesis of the VACTERL structures. What is lacking is the systematic study of individual genes and pathways in well-composed cohorts of patients, which is now possible with high throughput molecular technologies.

Congenital acinar dysplasia: report of a case and review of literature

Objective Describe a case of congenital acinar dysplasia and review the literature. Study Design Retrospective chart review and literature search. Results Congenital acinar dysplasia is a rare malformation of growth arrest of the lower respiratory tract resulting in critical respiratory insufficiency at birth. It is a form of pulmonary hypoplasia that is characterized by diffuse maldevelopment and derangement of the acinar and alveolar architecture of the lungs, resulting in the complete absence of gas exchanging units. The growth-arrested lung tissue resembles the pseudoglandular phase of 16 weeks' gestation. The etiology is unknown. It is diagnosed by exclusion of all other causes of pulmonary hypoplasia and a summation of clinical, imaging, and histopathologic findings. Conclusion There is no cure and clinical treatment is supportive until death of the infant. We present a case of congenital acinar dysplasia in a male infant who lived 20 days with intensive support.