Gene panel sequencing improves the diagnostic work-up of patients with idiopathic erythrocytosis and identifies new mutations
Open Access
- 20 September 2016
- journal article
- research article
- Published by Ferrata Storti Foundation (Haematologica) in Haematologica
- Vol. 101 (11), 1306-1318
- https://doi.org/10.3324/haematol.2016.144063
Abstract
Erythrocytosis is a rare disorder characterized by increased red cell mass and elevated hemoglobin concentration and hematocrit. Several genetic variants have been identified as causes for erythrocytosis in genes belonging to different pathways including oxygen sensing, erythropoiesis and oxygen transport. However, despite clinical investigation and screening for these mutations, the cause of disease cannot be found in a considerable number of patients, who are classified as having idiopathic erythrocytosis. In this study, we developed a targeted next-generation sequencing panel encompassing the exonic regions of 21 genes from relevant pathways (~79 Kb) and sequenced 125 patients with idiopathic erythrocytosis. The panel effectively screened 97% of coding regions of these genes, with an average coverage of 450×. It identified 51 different rare variants, all leading to alterations of protein sequence, with 57 out of 125 cases (45.6%) having at least one of these variants. Ten of these were known erythrocytosis-causing variants, which had been missed following existing diagnostic algorithms. Twenty-two were novel variants in erythrocytosis-associated genes (EGLN1, EPAS1, VHL, BPGM, JAK2, SH2B3) and in novel genes included in the panel (e.g. EPO, EGLN2, HIF3A, OS9), some with a high likelihood of functionality, for which future segregation, functional and replication studies will be useful to provide further evidence for causality. The rest were classified as polymorphisms. Overall, these results demonstrate the benefits of using a gene panel rather than existing methods in which focused genetic screening is performed depending on biochemical measurements: the gene panel improves diagnostic accuracy and provides the opportunity for discovery of novel variants.Keywords
This publication has 48 references indexed in Scilit:
- SomaticHIF2AGain-of-Function Mutations in Paraganglioma with PolycythemiaNew England Journal of Medicine, 2012
- Clinical utility gene card for: familial erythrocytosisEuropean Journal of Human Genetics, 2012
- A nonsynonymous LNK polymorphism associated with idiopathic erythrocytosisAmerican Journal of Hematology, 2011
- ANNOVAR: functional annotation of genetic variants from high-throughput sequencing dataNucleic Acids Research, 2010
- Structural Basis for Binding of Hypoxia-Inducible Factor to the Oxygen-Sensing Prolyl HydroxylasesStructure, 2009
- A Gain-of-Function Mutation in theHIF2AGene in Familial ErythrocytosisNew England Journal of Medicine, 2008
- Hypoxia-inducible factor–2 (HIF-2) regulates hepatic erythropoietin in vivoJCI Insight, 2007
- Acute postnatal ablation of Hif-2 α results in anemiaProceedings of the National Academy of Sciences of the United States of America, 2007
- JAK2Exon 12 Mutations in Polycythemia Vera and Idiopathic ErythrocytosisNew England Journal of Medicine, 2007
- Mutation of von Hippel–Lindau Tumour Suppressor and Human Cardiopulmonary PhysiologyPLoS Medicine, 2006