Esophageal atresia with tracheoesophageal fistula in both members of monozygotic twins

Outcomes of multi-gestational pregnancies affected by esophageal atresia - tracheoesophageal fistula

BACKGROUND

Contemporary outcomes of infants with esophageal atresia with or without tracheoesophageal fistula (EA/TEF) from multi-gestational pregnancies compared to those of singleton pregnancies have not been reported.

METHODS

A single-center retrospective review of EA/TEF patients born from 1999 to 2013 was performed. Patient demographics, gestational age (GA), birth weight, associated anomalies, requirement for gastrostomy tube and mortality were reviewed.

RESULTS

Singleton EA/TEF patients outnumbered those from multi-gestational pregnancies nearly 10:1 (214 vs 22 patients). EA/TEF patients from multi-gestational pregnancies were more likely to be premature (77% vs. 32%), have lower birth weight (mean 1766 g vs. 2695 g), have associated duodenal atresia (18% vs. 6%) and require gastrostomy tube (41% vs. 33%) for feeding challenges compared to EA/TEF singletons. Mortality was also significantly greater for multi-gestational EA/TEF patients compared to singleton EA/TEF patients (18% vs. 6%).

CONCLUSION

EA/TEF infants from multi-gestational pregnancies have greater clinical complexity and mortality than singleton EA/TEF patients. Parents of EA/TEF multi-gestational infants should be appropriately counseled and supported.

Nine new twin pairs with esophageal atresia: a review of the literature and performance of a twin study of the disorder

BACKGROUND

Isolated esophageal atresia (EA) is a rare congenital malformation whose etiology remains largely unknown. Nine twin pairs with EA were identified from our clinical service, prompting the performance of a systematic review of the literature and the first reported twin study of isolated EA.

METHODS

A total of 330 twin pairs with EA were identified from the literature. The zygosity, concordance, and malformation (isolated vs. nonisolated) status of all 339 twin pairs were evaluated. A total of 72 twin pairs (4 of 9 / 68 of 330) fulfilled the criteria for inclusion in a classic twin study of isolated EA.

RESULTS

The pairwise concordance rates were 50% (95% confidence interval [CI], 34-66%) for monozygous (MZ) twin pairs and 26% (95% CI, 15-42%) for dizygous (DZ) twin pairs (p = 0.033). The probandwise concordance rates were 67% (95% CI, 53-78%) for MZ twin pairs and 42% (95% CI, 29-56%) for DZ twin pairs (p = 0.011). The MZ/DZ ratios were 1.9 for pairwise analysis and 1.6 for probandwise analysis. The familial risk ratios for MZ and DZ twin pairs were 1700 and 900, respectively.

CONCLUSION

The observation of higher concordance rates for MZ compared to DZ twin pairs indicates that genetic factors contribute to isolated EA.

Copy number detection in discordant monozygotic twins of Congenital Diaphragmatic Hernia (CDH) and Esophageal Atresia (EA) cohorts

The occurrence of phenotypic differences between monozygotic (MZ) twins is commonly attributed to environmental factors, assuming that MZ twins have a complete identical genetic make-up. Yet, recently several lines of evidence showed that both genetic and epigenetic factors could have a role in phenotypic discordance after all. A high occurrence of copy number variation (CNV) differences was observed within MZ twin pairs discordant for Parkinson's disease, thereby stressing on the importance of post-zygotic mutations as disease-predisposing events. In this study, the prevalence of discrepant CNVs was analyzed in discordant MZ twins of the Esophageal Atresia (EA) and Congenital Diaphragmatic Hernia (CDH) cohort in the Netherlands. Blood-derived DNA from 11 pairs (7 EA and 4 CDH) was screened using high-resolution SNP arrays. Results showed an identical copy number profile in each twin pair. Mosaic chromosome gain or losses could not be detected either with a detection threshold of 20%. Some of the germ-line structural events demonstrated in five out of eleven twin pairs could function as a susceptible genetic background. For example, the 177-Kb loss of chromosome 10q26 in CDH pair-3 harbors the TCF7L2 gene (Tcf4 protein), which is implicated in the regulation of muscle fiber type development and maturation. In conclusion, discrepant CNVs are not a common cause of twin discordancy in these investigated congenital anomaly cohorts.