Oesophageal atresia, related malformations, and medical problems: a family study

Genomic Contributors to Esophageal Atresia and Tracheoesophageal Fistula: A 12 Year Retrospective Review

OBJECTIVE

To evaluate genetic testing utilization and diagnostic yield in infants with esophageal atresia (EA)/tracheoesophageal fistula (TEF) over the past 12 years to inform future practices and individualize prognostication and management.

STUDY DESIGN

A retrospective cohort study was performed for all infants with EA or EA/TEF hospitalized between January 2011 and January 2023 at a quaternary children's hospital. For each infant, demographic information, prenatal and postnatal history, and genetic testing were reviewed.

RESULTS

There were 212 infants who were classified as follows: 1) complex/syndromic with EA/TEF plus an additional major anatomic anomaly (n = 114, of which 74 met VACTERL criteria); 2) isolated/nonsyndromic EA/TEF (n = 88) and 3) isolated/nonsyndromic EA (n = 10). A range of genetic tests were sent with varying diagnostic rates including karyotype analysis in 12 (all with complex/syndromic phenotypes and all positive), chromosomal microarray analysis in 189 (114 of whom were complex/syndromic with an overall diagnostic rate of 3/189), single gene testing for CHD7 in 18 (4 positive), and exome analysis in 37 complex/syndromic patients (8 positive).

CONCLUSIONS

EA/TEF with and without additional anomalies is genetically heterogeneous with a broad range of associated phenotypes. While the genetic etiology of EA/TEF with or without VACTERL remains largely unknown, genome wide testing (exome or genome) including copy number analysis is recommended over chromosomal microarray testing. We anticipate that expanded genetic/genomic testing modalities such as RNA sequencing and tissue specific molecular testing are needed in this cohort to improve our understanding of the genomic contributors to EA/TEF.

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.

VACTERL associations in children undergoing surgery for esophageal atresia and anorectal malformations: Implications for pediatric surgeons

PURPOSE

The aim of this study was to compare the frequency and nature of VACTERL associations between children who underwent surgery for esophageal atresia/tracheoesophageal fistula (EA/TEF) and anorectal malformation (ARM).

METHODS

We identified all children who underwent surgery for EA/TEF and/or ARM at hospitals participating in the Pediatric Health Information System (PHIS) database between 2004 and 2012. PHIS is an administrative database of free-standing children's hospitals managed by the Child Health Corporation of America (Overland Park, KS) that contains patient-level care data from 43 hospitals. The complete records of patients in this cohort were cross-referenced for diagnoses of vertebral, cardiac, renal and limb anomalies.

RESULTS

2689 children underwent repair of esophageal atresia. Mean gestational age was 36.5±3.2weeks and mean birth weight was 2536.0±758.7g. Associated VACTERL diagnoses included vertebral anomaly in 686 (25.5%), ARM in 312 (11.6%), congenital heart disease in 1588 (59.1%), renal disease in 587 (21.8%) and limb defect in 192 (7.1%). 899 (33.4%) had 3 or more anomalies and met criteria for a VACTERL diagnosis. 4962 children underwent repair of ARM. Mean gestational age was 37.4±2.7weeks and mean birth weight was 2895.2±765.1g. Associated VACTERL diagnoses included vertebral anomaly in 1562 (31.5%), congenital heart disease in 2007 (40.4%), EA/TEF in 348 (7.0%), renal disease in 1723 (34.7%) and limb defect in 359 (7.2%). 1795 (36.2%) had 3 or more anomalies and met criteria for a VACTERL diagnosis.

CONCLUSION

VACTERL associations are relatively common in children with EA/TEF and ARM and occur in specific clusters, with cardiac disease more common in EA/TEF and spinal and renal/urinary anomalies more common in ARM.

Upper Airway Anomalies in Congenital Tracheoesophageal Fistula and Esophageal Atresia Patients

Objective:

To examine the prevalence of upper airway anomalies in patients diagnosed with congenital tracheoesophageal fistula and esophageal atresia (TEF/EA).

Methods:

A retrospective review was conducted of all TEF/EA patients seen at a tertiary pediatric hospital between January 2008 and December 2013. Inclusion criteria included evaluation by the otolaryngology service. Exclusion criteria included age >18 years, acquired TEF/EA, subsequent rule out of TEF/EA, and otolaryngology evaluation for reasons not pertaining to the airway. Data collected and analyzed included demographics, comorbidities, presenting symptoms, surgical interventions, laryngoscopic and bronchoscopic examinations, and subsequent medical and surgical management.

Results:

Four hundred and thirty patients were diagnosed with TEF/EA at our institution. In all, 32.3%, or 139 children, were included in the analysis; 56.1% (n = 78) male, 43.9% (n = 61) female. Of the analyzed patients, 4.3% (n = 6) were diagnosed with laryngomalacia. Eighteen patients (12.9%) were diagnosed with subglottic stenosis. Thirty (21.6%) had vocal fold paresis or immobility. Laryngeal cleft was diagnosed in 25.9% (n = 36). Tracheomalacia was the most common airway finding, diagnosed in 37.4% (n = 52) patients.

Conclusion:

Patients diagnosed with congenital TEF/EA have a high rate of secondary upper airway anomalies. Consideration should be given to perform a complete airway evaluation in all of these patients.

Second study on the recurrence risk of isolated esophageal atresia with or without trachea-esophageal fistula among first-degree relatives: no evidence for increased risk of recurrence of EA/TEF or for malformations of the VATER/VACTERL association spectrum

BACKGROUND

Esophageal atresia with/without trachea-esophageal fistula (EA/TEF) denotes a spectrum of severe congenital malformations. The aim of this systematic study was to determine both the recurrence risk for EA/TEF, and the risk for malformations of the VATER/VACTERL association spectrum, in first-degree relatives of patients with isolated EA/TEF.

METHODS

A total of 108 unrelated patients with isolated EA/TEF were included. These individuals had 410 first-degree relatives including 194 siblings. The presence of EA/TEF and malformations of the VATER/VACTERL association spectrum in relatives was systematically assessed. Data from the EUROCAT network were used for comparison.

RESULTS

None of the first-degree relatives displayed any form of EA/TEF. In two families, a first-degree relative presented with malformations from the VATER/VACTERL association spectrum. However, no increase in the risk for malformations of the VATER/VACTERL association spectrum was found compared with the control cohort (p = 0.87). In three families, one more distantly related relative presented with EA/TEF.

CONCLUSION

In contrast to previous studies, our results suggest a very low recurrence risk for isolated EA/TEF and/or for malformations of the VATER/VACTERL association spectrum among first-degree relatives.

VACTERL/VATER Association

VACTERL/VATER association is typically defined by the presence of at least three of the following congenital malformations: vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities. In addition to these core component features, patients may also have other congenital anomalies. Although diagnostic criteria vary, the incidence is estimated at approximately 1 in 10,000 to 1 in 40,000 live-born infants. The condition is ascertained clinically by the presence of the above-mentioned malformations; importantly, there should be no clinical or laboratory-based evidence for the presence of one of the many similar conditions, as the differential diagnosis is relatively large. This differential diagnosis includes (but is not limited to) Baller-Gerold syndrome, CHARGE syndrome, Currarino syndrome, deletion 22q11.2 syndrome, Fanconi anemia, Feingold syndrome, Fryns syndrome, MURCS association, oculo-auriculo-vertebral syndrome, Opitz G/BBB syndrome, Pallister-Hall syndrome, Townes-Brocks syndrome, and VACTERL with hydrocephalus. Though there are hints regarding causation, the aetiology has been identified only in a small fraction of patients to date, likely due to factors such as a high degree of clinical and causal heterogeneity, the largely sporadic nature of the disorder, and the presence of many similar conditions. New genetic research methods offer promise that the causes of VACTERL association will be better defined in the relatively near future. Antenatal diagnosis can be challenging, as certain component features can be difficult to ascertain prior to birth. The management of patients with VACTERL/VATER association typically centers around surgical correction of the specific congenital anomalies (typically anal atresia, certain types of cardiac malformations, and/or tracheo-esophageal fistula) in the immediate postnatal period, followed by long-term medical management of sequelae of the congenital malformations. If optimal surgical correction is achievable, the prognosis can be relatively positive, though some patients will continue to be affected by their congenital malformations throughout life. Importantly, patients with VACTERL association do not tend to have neurocognitive impairment.

Analysis of genitourinary anomalies in patients with VACTERL (Vertebral anomalies, Anal atresia, Cardiac malformations, Tracheo-Esophageal fistula, Renal anomalies, Limb abnormalities) association

The goal of this study was to describe a novel pattern of genitourinary (GU) anomalies in VACTERL association,which involves congenital anomalies affecting the vertebrae,anus, heart, trachea and esophagus, kidneys, and limbs.We collected clinical data on 105 patients diagnosed with VACTERL association and analyzed a subset of 89 patients who met more stringent inclusion criteria. Twenty-one percent of patients have GU anomalies, which are more severe (but not more frequent) in females. Anomalies were noted in patients without malformations affecting the renal, lower vertebral, or lower gastrointestinal systems. There should be a high index of suspicion for the presence of GU anomalies even in patients who do not have spatially similar malformations.

Reduction of interstitial cells of Cajal in esophageal atresia

OBJECTIVES

Postrepair esophageal dysmotility and gastroesophageal reflux are well-known consequences in patients with congenital esophageal atresia (EA) with or without distal tracheoesophageal fistula (TEF). The interstitial cells of Cajal (ICC), considered the intestinal pacemaker, are altered in congenital diseases with abnormal peristalsis, but no data are available for EA. Therefore, presence and maturation of ICC was verified in EA-TEF newborns.

PATIENTS AND METHODS

Fifteen full-term neonates underwent repair of EA-TEF. Control specimens were from 10 newborns who died of nonesophageal diseases. Specimens from upper pouch, fistula, proximal, and distal esophagus were processed for hematoxylin and eosin, c-kit immunohistochemistry for ICC identification, and transmission electron microscopy. Frequency of c-kit-positive cells was evaluated in 20 fields per slide using a visual score (absent, very low, low, medium, high, very high). Morphocytometry and statistical analysis were also performed.

RESULTS

In the proximal normal esophagus, ICC frequency was very high (3 cases), high (5), and medium (2); distally, it was high (4) and medium (6). In EA-TEF upper pouch, it was high (2) and medium (13); in the fistula, it was medium (5), low (6), very low (3), and absent (1). Morphocytometry confirmed these results. Comparison between pouch and fistula versus proximal and lower esophagus, respectively, showed statistically significant differences. Transmission electron microscopy demonstrated ICC immaturity in EA-TEF.

CONCLUSIONS

The significant lower ICC density in EA-TEF is in favor for the pathogenesis of esophageal dysmotility frequently observed in such patients.

Evidence for inheritance in patients with VACTERL association

VACTERL/VATER association is typically a sporadic disorder. We present data on inheritance in 78 probands with VACTERL association, and show that 9% of probands have a primary relative with at least one component feature of VACTERL association. The prevalence of component features in first-degree relatives is significantly higher than expected in the general population, which has implications for counseling of affected families and for research into possible etiologies.

Embryology of oesophageal atresia

Esophageal atresia (OA) and tracheoesophageal fistula (TOF) are important human birth defects of unknown etiology. The embryogenesis of OA/TOF remains poorly understood, mirroring the lack of clarity of the mechanisms of normal tracheoesophageal development. The development of rat and mouse models of OA/TOF has allowed the parallel study of both normal and abnormal embryogenesis. Although controversies persist, the fundamental morphogenetic process appears to be a rearrangement of the proximal foregut into separate respiratory (ventral) and gastrointestinal (dorsal) tubes. This process depends on the precise temporal and spatial pattern of expression of a number of foregut patterning genes. Disturbance of this pattern disrupts foregut separation and underlies the development of tracheoesophageal malformations.

An overview of isolated and syndromic oesophageal atresia

Oesophageal atresia (OA) and/or tracheo-oesophageal fistula (TOF) are frequent malformations observed in approximately one in 3500 births. OA/TOF can be divided clinically into isolated OA (IOA) and syndromic OA (SOA) when associated with other features, the most frequent being cardiac, limb and vertebral malformations or anal atresia. SOA is observed in 50% of patients and can be subdivided into several causative groups comprising environmental agents, chromosomal disorders, malformative associations (CHARGE syndrome and VATER/VACTERL association), and other multiple congenital anomaly disorders. The observation of chromosomal disorders with SOA, as well as mouse models of OA provide support for the involvement of genetic factors in OA. Yet, epidemiological data (twin and family studies) do not support the major role of genetic factors in the majority of cases of IOA but rather a multifactorial model. However, several genes involved in SOA have been recently identified, namely N-MYC, SOX2, and CHD7 involved in Feingold (MIM 164280), anophthalmia-oesophageal-genital (MIM 600992) and CHARGE syndromes respectively (MIM 214800), suggesting that OA/TOF, at least in their syndromic forms, may be a highly genetically heterogeneous group.

Gastroesophageal reflux and related pathology in adults who were born with esophageal atresia: a long-term follow-up study

BACKGROUND & AIMS

Esophageal atresia (EA) is the most common congenital anomaly of the esophagus. There are few long-term follow-up data on adults who had surgery for EA as infants. The primary aims were to evaluate the prevalence of esophageal symptoms and pathology and second to develop recommendations for follow-up.

METHODS

This is a descriptive study of individuals attending a clinic in an adult tertiary referral hospital, established to provide care for adults who had surgery for EA as infants. Individuals aged 20 years or older were identified from an existing database and invited by telephone to attend the clinic. One hundred thirty-two patients attended the clinic from 2000-2003. Individuals were assessed by using a structured questionnaire. Endoscopy was performed in 62 patients because of symptoms.

RESULTS

Reflux symptoms were reported by 83 (63%), including 25 (19%) with severe symptoms. Dysphagia was reported by 68 patients (52%). Of those who underwent endoscopy, reflux esophagitis was present in 36 patients (58%), Barrett's esophagus in 7 (11%), and strictures in 26 (42%) patients. One patient was diagnosed with esophageal squamous cell carcinoma. Men who were 35 years or older and individuals with severe reflux symptoms were at high risk of having severe esophagitis or Barrett's metaplasia.

CONCLUSIONS

Reflux symptoms, esophagitis, and Barrett's esophagus are common in these individuals. We recommend clinical assessment as adults and upper endoscopy for reflux symptoms or dysphagia. Transition of young adults from pediatric care to an adult gastroenterology clinic with expertise in EA appears to be highly beneficial.

Expression of homeotic genes Hoxa3, Hoxb3, Hoxd3 and Hoxc4 is decreased in the lungs but not in the hearts of adriamycin-exposed mice

Exposure of rat and mouse embryos to adriamycin (doxorubicin chlorhydrate) induces esophageal atresia (EA) and VACTERL association. Sonic hedgehog (Shh) and Gli2/Gli3 pathways are involved in these conditions and knockout mice for homeotic Hox genes Hoxa3, Hoxb3, Hoxc3, Hoxc4 and Hoxa5 show phenotypes with some of the associated VACTERL features. This study aims at evaluating the possible influence of Hoxa3, Hoxb3, Hoxd3 and Hoxc4 as upstream regulators of this complex signalling. Pregnant mice were exposed either to 4 mg/kg of adriamycin (EA group) or vehicle (controls) on embryonic days 7.5 and 8.5. Embryos were recovered at four endpoints (E12.5-E15.5) and randomly assigned for immunohistochemical or molecular biology studies. Lungs and hearts were separately harvested and processed for Hoxa3, Hoxb3, Hoxd3 and Hoxc4 quantitative RT-PCR measurements. Antibodies for Hoxa3, Hoxb3 and Hoxd3 proteins were used for immunohistochemical studies. RT-PCR studies showed a drastic and statistically significant decrease of the four genes in the lungs of EA mice when compared to controls, with a slight recovery from E15.5. Hearts of both groups showed a similar expression of all the genes throughout gestation. Control embryos expressed the hox3 paralogous genes in heart, skin, foregut derivatives and their surrounding mesoderm through E12.5-E15.5 whereas adriamycin-exposed embryos showed a severe decrease in expression of these three proteins in the same tissues but not in the heart. Adriamycin drastically reduced the expression of Hoxa3, Hoxb3, Hoxd3 and Hoxc4 in mice embryonic lungs. Their expression in the heart did not seem to be influenced by adriamycin in this experimental setting.

Esophageal atresia. Lessons I have learned in a 40-year experience

A brief resume of the highlights in the history of oesophageal atresia is presented. This is followed by research into the etiology, ontogeny and embryology, and microbiological studies. A revised classification of risk factors with consequent survival statistics is presented. Lessons learned in the management of the condition over a 40-year period are reported with particular emphasis on the management of the preterm infant with associated severe respiratory distress, right-side aortic arch, upper pouch fistula, 'long-gap' atresia, and the use of gastrostomy and intercostals drains. The incidence and treatment of early and late complications is discussed.

Oesophageal atresia, tracheo-oesophageal fistula, and the VACTERL association: review of genetics and epidemiology

Oesophageal atresia and/or tracheo-oesophageal fistula are relatively common malformations occurring in approximately 1 in 3500 births. In around half of the cases (syndromic oesophageal atresia), there are associated anomalies, with cardiac malformations being the most common. In the remainder (non-syndromic cases), oesophageal atresia/tracheo-oesophageal fistula occur in isolation. Data from twin and family studies suggest that genetic factors do not play a major role, and yet there are well-defined instances of this malformation where genetic factors clearly are important. This is highlighted by the recent identification of no fewer than three separate genes with a role in the aetiology of oesophageal atresia: those for Feingold syndrome (N-MYC), anophthalmia-oesophageal-genital (AEG) syndrome (SOX2), and CHARGE syndrome (CHD7). Additional support for genetic factors in this malformation comes from chromosomal studies and mouse models. This paper reviews current knowledge of the genetics and epidemiology of the different oesophageal atresia/tracheo-oesophageal fistula syndromes and associations.

Genetic players in esophageal atresia and tracheoesophageal fistula

Esophageal atresia is a common and serious developmental anomaly, of which the causes remain largely unknown. Studies in vertebrate models indicate the importance of the sonic hedgehog pathway in esophageal atresia, but its relevance to the human condition remains to be defined. Now, three genes have been identified that cause syndromic forms of esophageal atresia when mutated. NMYC and SOX2 are transcription factors, whereas CHD7 is encoded by a chromodomain helicase DNA-binding gene, important for chromatin structure and gene expression. These new genes broaden our view of human foregut development.

A new autosomal recessive oto-facial syndrome with midline malformations

Two sisters from a Lebanese family presented with slight developmental delay, short stature, congenital microcephaly, frontal bossing, mild hyperplastic supra-orbital ridges, broad nasal root, small dysplastic low-set ears, high arched palate, short neck, and hearing impairment. In addition, the oldest affected sister had esophageal atresia and the other sister had cleft palate. Temporal bone abnormalities included hypoplasia of the external auditory canal, small middle ear cavity, abnormal ossicles, and inner ear malformations with enlarged vestibular acqueducts. Differential diagnosis is discussed, and the possibility of a newly recognized autosomal recessive syndrome is raised.