Rare copy number variants contribute pathogenic alleles in patients with intestinal malrotation

Abstract

Background: Intestinal malrotation is a potentially life-threatening congenital anomaly due to the risk of developing midgut volvulus. The reported incidence is 0.2%–1% and both apparently hereditary and sporadic cases have been reported. Intestinal malrotation is associated with a few syndromes with known genotype but the genetic contribution in isolated intestinal malrotation has not yet been reported. Rare copy number variants (CNVs) have been implicated in many congenital anomalies, and hence we sought to investigate the potential contribution of rare CNVs in intestinal malrotation. Methods: Analysis of array comparative genomic hybridization (aCGH) data from 47 patients with symptomatic intestinal malrotation was performed. Results: We identified six rare CNVs in five patients. Five CNVs involved syndrome loci: 7q11.23 microduplication, 16p13.11 microduplication, 18q terminal deletion, HDAC8 (Cornelia de Lange syndrome type 5 and FOXF1) as well as one intragenic deletion in GALNT14, not previously implicated in human disease. Conclusion: In the present study, we identified rare CNVs contributing pathogenic or potentially pathogenic alleles in five patients with syndromic intestinal malrotation, suggesting that CNV screening is indicated in intestinal malrotation with associated malformations or neurological involvements. In addition, we identified intestinal malrotation in two known syndromes (Cornelia de Lange type 5 and 18q terminal deletion syndrome) that has not previously been associated with gastrointestinal malformations.