Esophageal and duodenal atresia in a girl with a 12q24.3-qter deletion

Microarray analysis in fetuses with duodenal obstruction: It is not just trisomy 21

OBJECTIVE

To explore the copy number variants (CNVs) in case of fetal duodenal obstruction (DO) and assess the associated prenatal findings and postnatal outcomes.

MATERIALS AND METHODS

This retrospective study reviewed 51 fetuses with DO and the findings of chromosomal microarray analysis (CMA) used as a first-tier test in our institution between January 2014 and May 2019.

RESULTS

The frequency of pathogenic aberrations in fetuses with DO was 15.7% (8/51), including 9.8% (5/51) pathogenic CNVs. Three fetuses with isolated DO each had a deletion on chromosome 13q, one fetus had duplication at 1q43q44, and one had microduplication at 17q12. No significant differences in pathogenic CNVs were observed between isolated DO and DO plus additional anomalies (4/42, 9.5% vs 1/9, 11.1%, P = .89). Of the 51 fetuses with DO, 11 pregnancies were terminated, and eight fetuses had chromosomal abnormalities; one pregnancy ended with intrauterine death, and there were 39 live births. Neonatal outcomes were available for 31 fetuses, and no neonatal deaths occurred after surgery.

CONCLUSIONS

Our cohort study demonstrated the value of CMA in fetuses with DO, suggesting that CNVs may underly genetic etiologies that should be considered in the diagnostic evaluation of DO. We think CMA should be recommended in case of DO.

Chromosome aberrations and gene mutations in patients with esophageal atresia

Esophageal atresia (EA) is one of the most frequent congenital malformations of the gastrointestinal tract. Many genetic alterations in patients with EA have been described in the literature. It is thought that the etiology of EA is heterogeneous. This review of the literature provides detailed information about chromosomal aberrations, gene mutations, and clinical features of neonates with EA, and serves as an excellent source to compare newly diagnosed patients with those described in the literature.

Chromosomal anomalies in the aetiology of oesophageal atresia and tracheo-oesophageal fistula

Oesophageal atresia (OA) and tracheo-oesophageal fistula (TOF) are severe congenital anomalies of which the aetiology is largely unknown. Several chromosomal anomalies have been described in patients presenting with these anatomical malformations, but until now none of these has led to the identification of a single aetiological factor. This paper reviews the chromosomal abnormalities reported in cases of OA/TOF and serves as a starting point to identify chromosomal regions harbouring genes involved in the aetiology of OA/TOF.

Oesophageal atresia with a terminal deletion of chromosome 2q37.1

We herein report the case of a newborn girl with oesophageal atresia associated with cardiac and gastrointestinal anomalies, including patent ductus arteriosus, tracheomalacia, and gastro-oesophageal reflux with hiatus hernia. In addition, she had a terminal deletion of the long arm of chromosome 2, with a breakpoint of 2q37.1. The patient died following a cardiac arrest at 90 days of age. No cause of death was identified at autopsy.

Fibroblast growth factor-10 serves a regulatory role in duodenal development

PURPOSE

Duodenal obstruction occurs in 1 of 6000 live births and requires urgent surgical intervention. Duodenal atresia previously has been ascribed to a developmental failure of luminal recanalization; however, the cause of duodenal atresia remains incompletely understood. Although familial intestinal atresias have been described and syndromic associations are known, no specific genetic link has been established. Fibroblast growth factor-10 (Fgf10) is a known regulatory molecule relevant to mesenchymal-epithelial interactions, and mice deficient in Fgf10 demonstrate congenital anomalies in several organ systems including the gastrointestinal tract. The authors hypothesized that Fgf10 could serve a regulatory role in establishing normal duodenal development.

METHODS

Wild-type mice with beta-galactosidase under the control of the Fgf10 promoter were harvested from timed-pregnancy mothers. The expression of Fgf10 in the duodenum during development was evaluated by developing the embryos in X-Gal solution. Wild-type and mutant Fgf10(-/-) embryos were harvested from timed-pregnancy mothers at 18.5 days postconception (near term) and were analyzed for duodenal morphology (Institutional Animal Care and Use Committee-approved protocol 32-02). Photomicrographs were reviewed.

RESULTS

Fibroblast growth factor-10 is active in the duodenum at a late stage of development. The Fgf10(-/-) mutants demonstrate duodenal atresia with a variable phenotype similar to clinical findings. The duodenum fails to develop luminal continuity and has proximal dilation. The phenotype occurs in an autosomal recessive pattern with incomplete penetrance (38%).

CONCLUSIONS

Fibroblast growth factor-10 serves as a regulator in normal duodenal growth and development. Its deletion leads to duodenal atresia and challenges traditionally accepted theories of pathogenesis. This novel, genetically mediated duodenal malformation reflects an animal model that will allow further evaluation of the pathogenesis of this surgically correctable disease. By studying the mechanism of Fgf10 function in foregut development, the authors hope to better understand these anomalies and to explore possible therapeutic alternatives.