Mutation Screening and Array Comparative Genomic Hybridization Using a 180K Oligonucleotide Array in VACTERL Association

Johanna Winberg,Erik Iwarsson,Ellika Sahlin,Edvard Nordenskjöld,Göran Annerén,Pär-Johan Svensson,Agneta Nordenskjöld,Nikos Papadogiannakis,Peter Gustavsson,Ann Nordgren,Frideborg Bradley

doi:10.1371/journal.pone.0085313

Johanna Winberg, Erik Iwarsson + Show 9 more

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https://doi.org/10.1371/journal.pone.0085313

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Abstract

In order to identify genetic causes of VACTERL association (V vertebral defects, A anorectal malformations, C cardiac defects, T tracheoesofageal fistula, E esophageal atresia, R renal anomalies, L limb deformities), we have collected DNA samples from 20 patients diagnosed with VACTERL or with a VACTERL-like phenotype as well as samples from 19 aborted fetal cases with VACTERL. To investigate the importance of gene dose alterations in the genetic etiology of VACTERL association we have performed a systematic analysis of this cohort using a 180K array comparative genomic hybridization (array-CGH) platform. In addition, to further clarify the significance of PCSK5, HOXD13 and CHD7 genes in the VACTERL phenotype, mutation screening has been performed. We identified pathogenic gene dose imbalances in two fetal cases; a hemizygous deletion of the FANCB gene and a (9;18)(p24;q12) unbalanced translocation. In addition, one pathogenic mutation in CHD7 was detected, while no apparent disease-causing mutations were found in HOXD13 or PCSK5. Our study shows that although large gene dose alterations do not seem to be a common cause in VACTERL association, array-CGH is still important in clinical diagnostics to identify disease cause in individual cases.

Highlights

VACTERL association (OMIM #192350) is described as the non-random association of multiple congenital anomalies affecting the specific organ systems intended in its letters; V vertebral anomalies, A anal atresia, C cardiac defects, T tracheoesophageal fistula, E esophageal atresia, R renal anomalies and L limb defects
Multiplex Ligation-dependent Probe Amplification (MLPA) for FANCB performed at the Centogene laboratory confirmed deletion of the complete FANCB gene in the fetus, a finding associated with the diagnosis of X-linked VACTERL (Fig. 2c)
In the second fetal case, a whole-gene deletion of FANCB was identified together with a dup(16)(p12.3p13.11) that has been associated with malformations [27,28]

Summary

Introduction

VACTERL association (OMIM #192350) is described as the non-random association of multiple congenital anomalies affecting the specific organ systems intended in its letters; V vertebral anomalies, A anal atresia, C cardiac defects, T tracheoesophageal fistula, E esophageal atresia, R renal anomalies and L limb defects. No common etiology of VACTERL association is known and a heterogeneous background to the phenotype is likely [1]. In the majority of cases, VACTERL association occurs sporadically which has lead to suggestions of environmental causative factors [1], but the condition is familial in rare cases [3,4,5] indicating the possibility of a genetic etiology [6]. Genetic counseling for families with VACTERL association based on current knowledge is unsatisfactory and studies exploring genetic and environmental factors are important to improve the situation as advances in pediatric surgery and intensive care have increased survival rates of children with multiple congenital anomalies

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