Rajkumar, A.P.12; Christensen, Jane H.12; Mattheisen, Manuel12; Jacobsen, Iben6; Bache, Iben7; Pallesen, Jonatan12; Grove, Jakob12; Qvist, Per12; Mcquillin, Andrew8; Gurling, Hugh M.9; Tümer, Zeynep10; Mors, Ole13; Børglum, Anders D.12
1 Department of Biomedicine - Forskning og uddannelse, Øst, Department of Biomedicine, Health, Aarhus University2 Department of Clinical Medicine - Translational Neuropsychiatry Unit, Department of Clinical Medicine, Health, Aarhus University3 Aarhus University4 Bioinformatics Research Centre (BiRC), Science and Technology, Aarhus University5 Department of Clinical Medicine - The Department of General Psychiatry, Department of Clinical Medicine, Health, Aarhus University6 The Study Committee for Law, Faculty of Social Sciences, Aarhus University, Aarhus University7 Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine, Faculty of Health Science, University of Copenhagen8 Molecular Psychiatry Laboratory, Division of Psychiatry, University College London9 Molecular Psychiatry Laboratory, Division of Psychiatry, University College London10 Applied Molecular Genetics, Kennedy Center, Copenhagen University Hospital, Rigshospitalet11 Department of Clinical Medicine - Afdeling for Psykoser, afd. P, Department of Clinical Medicine, Health, Aarhus University12 Department of Biomedicine - Forskning og uddannelse, Øst, Department of Biomedicine, Health, Aarhus University13 Department of Clinical Medicine - Afdeling for Psykoser, afd. P, Department of Clinical Medicine, Health, Aarhus University
OBJECTIVES: Breakpoints of chromosomal abnormalities facilitate identification of novel candidate genes for psychiatric disorders. Genome-wide significant evidence supports the linkage between chromosome 17q25.3 and bipolar disorder (BD). Co-segregation of translocation t(9;17)(q33.2;q25.3) with psychiatric disorders has been reported. We aimed to narrow down these chromosomal breakpoint regions and to investigate the associations between single nucleotide polymorphisms within these regions and BD as well as schizophrenia (SZ) in large genome-wide association study samples. METHODS: We cross-linked Danish psychiatric and cytogenetic case registers to identify an individual with both t(9;17)(q33.2;q25.3) and BD. Fluorescent in situ hybridization was employed to map the chromosomal breakpoint regions of this proband. We accessed the Psychiatric Genomics Consortium BD (n = 16,731) and SZ (n = 21,856) data. Genetic associations between these disorders and single nucleotide polymorphisms within these breakpoint regions were analysed by BioQ, FORGE, and RegulomeDB programmes. RESULTS: Four protein-coding genes [coding for (endonuclease V (ENDOV), neuronal pentraxin I (NPTX1), ring finger protein 213 (RNF213), and regulatory-associated protein of mammalian target of rapamycin (mTOR) (RPTOR)] were found to be located within the 17q25.3 breakpoint region. NPTX1 was significantly associated with BD (p = 0.004), while ENDOV was significantly associated with SZ (p = 0.0075) after Bonferroni correction. CONCLUSIONS: Prior linkage evidence and our findings suggest NPTX1 as a novel candidate gene for BD.