Esophageal atresia in twins compared to singletons: In utero manifestation and characteristics

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.

Epigenetic Findings in Twins with Esophageal Atresia

Esophageal atresia (EA) is the most common malformation of the upper gastrointestinal tract. The estimated incidence of EA is 1 in 3500 births. EA is more frequently observed in boys and in twins. The exact cause of isolated EA remains unknown; a multifactorial etiology, including epigenetic gene expression modifications, is considered. The study included six pairs of twins (three pairs of monozygotic twins and three pairs of dizygotic twins) in which one child was born with EA as an isolated defect, while the other twin was healthy. DNA samples were obtained from the blood and esophageal tissue of the child with EA as well as from the blood of the healthy twin. The reduced representation bisulfite sequencing (RRBS) technique was employed for a whole-genome methylation analysis. The analyses focused on comparing the CpG island methylation profiles between patients with EA and their healthy siblings. Hypermethylation in the promoters of 219 genes and hypomethylation in the promoters of 78 genes were observed. A pathway enrichment analysis revealed the statistically significant differences in methylation profile of 10 hypermethylated genes in the Rho GTPase pathway, previously undescribed in the field of EA (ARHGAP36, ARHGAP4, ARHGAP6, ARHGEF6, ARHGEF9, FGD1, GDI1, MCF2, OCRL, and STARD8).

Oesophageal atresia: sonographic signs may prenatally predict surgical complexity

OBJECTIVE

Oesophageal atresia (OA) is a major anomaly of varying severity. The complexity of surgical correction highly depends on the gap length of missing oesophagus and the presence of a distal fistula. The aim of this study was to identify antenatal sonographic findings associated with presence of a distal fistula and type of surgical repair METHODS: Prenatal medical records of neonates postnatally diagnosed with OA were reviewed. Sonographic signs of OA (small/absent stomach, polyhydramnios, oesophageal pouch) and the trimester at sign detection were recorded and compared between (1) OA with and without a distal fistula and (2) early one-step versus delayed two-step anastomosis. Multivariate analysis was performed.

RESULTS

Overall, 80 cases of OA were included. Absence of a distal fistula was significantly associated with higher rates of small/absent stomach (100% vs 28.6%, P<0.0001), oesophageal pouch (100% vs 24.3%, P<0.0001) and severe polyhydramnios (66.7% vs 22.9%, P=0.006), compared with OA with a distal fistula.Cases requiring a delayed two-step repair had higher rates of small/absent stomach (84.2% vs 16.7%, P>0.0001), severe polyhydramnios (47.4% vs 16.7%, P=0.008) and oesophageal pouch (73.7% vs 18.5%, P<0.0001), compared with those corrected in an early one-step anastomosis.Multivariate logistic regression found small/absent stomach and pouch to be significantly and independently associated with a delayed two-step anastomosis.

CONCLUSION

OA without a distal fistula is associated with higher rates of prenatal sonographic signs. Both small/absent stomach and a pouch are independently associated with a delayed two-step anastomosis. These findings may help improve antenatal parental counselling regarding the anticipated surgical repair.