Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.

Copy number variations (CNVs) are one of the main sources of variability in the human genome. Many CNVs are associated with various diseases including cardiovascular disease. In addition to hybridization-based methods, next-generation sequencing (NGS) technologies are increasingly used for CNV disco...

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Main Authors: Vikas Bansal, Cornelia Dorn, Marcel Grunert, Sabine Klaassen, Roland Hetzer, Felix Berger, Silke R Sperling
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0085375
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author Vikas Bansal
Cornelia Dorn
Marcel Grunert
Sabine Klaassen
Roland Hetzer
Felix Berger
Silke R Sperling
author_facet Vikas Bansal
Cornelia Dorn
Marcel Grunert
Sabine Klaassen
Roland Hetzer
Felix Berger
Silke R Sperling
author_sort Vikas Bansal
collection DOAJ
description Copy number variations (CNVs) are one of the main sources of variability in the human genome. Many CNVs are associated with various diseases including cardiovascular disease. In addition to hybridization-based methods, next-generation sequencing (NGS) technologies are increasingly used for CNV discovery. However, respective computational methods applicable to NGS data are still limited. We developed a novel CNV calling method based on outlier detection applicable to small cohorts, which is of particular interest for the discovery of individual CNVs within families, de novo CNVs in trios and/or small cohorts of specific phenotypes like rare diseases. Approximately 7,000 rare diseases are currently known, which collectively affect ∼6% of the population. For our method, we applied the Dixon's Q test to detect outliers and used a Hidden Markov Model for their assessment. The method can be used for data obtained by exome and targeted resequencing. We evaluated our outlier-based method in comparison to the CNV calling tool CoNIFER using eight HapMap exome samples and subsequently applied both methods to targeted resequencing data of patients with Tetralogy of Fallot (TOF), the most common cyanotic congenital heart disease. In both the HapMap samples and the TOF cases, our method is superior to CoNIFER, such that it identifies more true positive CNVs. Called CNVs in TOF cases were validated by qPCR and HapMap CNVs were confirmed with available array-CGH data. In the TOF patients, we found four copy number gains affecting three genes, of which two are important regulators of heart development (NOTCH1, ISL1) and one is located in a region associated with cardiac malformations (PRODH at 22q11). In summary, we present a novel CNV calling method based on outlier detection, which will be of particular interest for the analysis of de novo or individual CNVs in trios or cohorts up to 30 individuals, respectively.
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spelling doaj-art-8507afd5487b4e10898e10604e2e3f002025-08-20T02:22:49ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0191e8537510.1371/journal.pone.0085375Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.Vikas BansalCornelia DornMarcel GrunertSabine KlaassenRoland HetzerFelix BergerSilke R SperlingCopy number variations (CNVs) are one of the main sources of variability in the human genome. Many CNVs are associated with various diseases including cardiovascular disease. In addition to hybridization-based methods, next-generation sequencing (NGS) technologies are increasingly used for CNV discovery. However, respective computational methods applicable to NGS data are still limited. We developed a novel CNV calling method based on outlier detection applicable to small cohorts, which is of particular interest for the discovery of individual CNVs within families, de novo CNVs in trios and/or small cohorts of specific phenotypes like rare diseases. Approximately 7,000 rare diseases are currently known, which collectively affect ∼6% of the population. For our method, we applied the Dixon's Q test to detect outliers and used a Hidden Markov Model for their assessment. The method can be used for data obtained by exome and targeted resequencing. We evaluated our outlier-based method in comparison to the CNV calling tool CoNIFER using eight HapMap exome samples and subsequently applied both methods to targeted resequencing data of patients with Tetralogy of Fallot (TOF), the most common cyanotic congenital heart disease. In both the HapMap samples and the TOF cases, our method is superior to CoNIFER, such that it identifies more true positive CNVs. Called CNVs in TOF cases were validated by qPCR and HapMap CNVs were confirmed with available array-CGH data. In the TOF patients, we found four copy number gains affecting three genes, of which two are important regulators of heart development (NOTCH1, ISL1) and one is located in a region associated with cardiac malformations (PRODH at 22q11). In summary, we present a novel CNV calling method based on outlier detection, which will be of particular interest for the analysis of de novo or individual CNVs in trios or cohorts up to 30 individuals, respectively.https://doi.org/10.1371/journal.pone.0085375
spellingShingle Vikas Bansal
Cornelia Dorn
Marcel Grunert
Sabine Klaassen
Roland Hetzer
Felix Berger
Silke R Sperling
Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.
PLoS ONE
title Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.
title_full Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.
title_fullStr Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.
title_full_unstemmed Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.
title_short Outlier-based identification of copy number variations using targeted resequencing in a small cohort of patients with Tetralogy of Fallot.
title_sort outlier based identification of copy number variations using targeted resequencing in a small cohort of patients with tetralogy of fallot
url https://doi.org/10.1371/journal.pone.0085375
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