KDM2B Is Implicated in Bovine Lethal Multi-Organic Developmental Dysplasia Stefania Testoni1, Elena Bartolone2,7, Marco Rossi2,7, Andrea Patrignani3, Re´ my Bruggmann3,4, Peter Lichtner5, Jens Tetens6, Arcangelo Gentile2, Cord Dro¨ gemu¨ ller7* 1 Department of Veterinary Clinical Sciences, University of Padua, Legnaro, Padua, Italy, 2 Veterinary Clinical Department, University of Bologna, Ozzano Emilia, Bologna, Italy, 3 Functional Genomics Center Zu¨ rich, University/ETH Z u¨rich, Zu¨ rich, Switzerland, 4 Department of Biology, University of Bern, Bern, Switzerland, 5 Institute of Human Genetics, Helmholtz Zentrum Mu¨ nchen, German Research Center for Environmental Health, Neuherberg, Germany, 6 Institute for Animal Breeding and Husbandry, Christian-Albrechts-University Kiel, Kiel, Germany, 7 Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland Abstract In the last decade breeders of Romagnola cattle observed an outbreak of a new congenital anomaly. This lethal multi-organ developmental dysplasia is mainly characterized by facial deformities, ascites and hepatic fibrosis. Affected stillborn calves were inbred to a single founder sire suggesting autosomal monogenic recessive inheritance. We localized the causative mutation to a 1.2 Mb interval on BTA 17 by genome-wide association and identical by descent mapping. A solution-based method for targeted DNA capture combined with massively parallel sequencing was used to analyze the entire critical region containing 24 genes. Homozygosity for two non-synonymous coding sequence variants affecting the RNF34 and KDM2B genes was detected by evaluating one affected calf. Here we show that the disease phenotype is associated with a KDM2B missense mutation (c.2503G.A) leading to an amino acid exchange (p.D835N) in an evolutionary strongly conserved domain. In addition, the genetic makeup of three inbred cattle strongly supports the causality of the KDM2B mutation. This report of a naturally-occurring spontaneous mutation of a JmjC domain containing histone demethylase gene provides evidence for their important role in the endo- and mesodermal organ development. Citation: Testoni S, Bartolone E, Rossi M, Patrignani A, Bruggmann R, et al. (2012) KDM2B Is Implicated in Bovine Lethal Multi-Organic Developmental Dysplasia. PLoS ONE 7(9): e45634. doi:10.1371/journal.pone.0045634 Editor: Osman El-Maarri, University of Bonn, Germany Received June 5, 2012; Accepted August 21, 2012; Published September 27, 2012 Copyright: 2012 Testoni et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: The authors thank the region of Emilia Romagna (Italy) for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: cord.droegemueller@vetsuisse.unibe.ch Introduction Since 2003 breeders of Romagnola cattle in Italy have experienced an increase in the occurrence of a previously unknown complex congenital anomaly, mainly characterized by craniofacial deformities, an enlarged fluid-filled abdomen and hepatic fibrosis [1]. Affected calves are usually stillborn and the disease is known as ‘paunch calf syndrome’ (Figure 1). The emerging paunch calf syndrome disease causes significant economic and animal welfare concerns. The paunch calf syndrome defect is supposed to be inherited as a monogenic autosomal recessive trait [1]. The outbreak of paunch calf syndrome can be attributed to selective breeding practices involving the extensive use of particular highly selected artificial insemination sires leading to an increase in co-ancestry and inbreeding [2]. Parents of affected calves do not present any clinical signs. Therefore, it is crucial that the breeders implement an effective strategy to control this recessive defect [1,3]. Identification of the causative mutation has an immediate translation into breeding practice, allowing direct DNA testing and effective selection against the defect through avoidance of at- risk matings [2]. After sequencing the cow genome [4,5] recent examples showed that the availability of genome-wide, high- density SNP arrays, combined with the typical structure of cattle populations, markedly accelerates the positional identification of genes and mutations that cause inherited recessive defects [2,6,7]. In humans and other mammalian species a comparable syndrome has also not yet been described. Lacking functional candidate genes for this unique phenotype, the spontaneous cattle paunch calf syndrome mutants provide the potential to gain insights into the pathogenesis of this developmental dysplasia affecting several endo- and mesodermal derived organs. The aim of our investigation was to identify the mutation associated with paunch calf syndrome in Romagnola cattle using a genome-wide association study mapping approach, followed by targeted re-sequencing of the entire disease locus. Results The Paunch Calf Syndrome Mutation Maps to BTA 17 We genotyped 777,962 SNPs in 16 paunch calf syndrome affected calves and 41 controls. After removing non-informative markers 536,171 SNPs were used for the subsequent analyses. A genome-wide association study revealed a single strong signal for paunch calf syndrome on bovine chromosome (BTA) 17 (Figure 2A). The best-associated SNP had a genome-wide corrected p-value of 1.061024 at 56,938,011 bp on BTA 17 (Figure 2B). PLOS ONE | www.plosone.org 1 September 2012 | Volume 7 | Issue 9 | e45634