title: A genetic association study of chromosome 11q22-24 in two different samples implicates the FXYD6 gene, encoding phosphohippolin, in susceptibility to schizophrenia.
abstract: Previous linkage analyses of families with multiple cases of schizophrenia by us and others have confirmed the involvement of the chromosome 11q22-24 region in the etiology of schizophrenia, with LOD scores of 3.4 and 3.1. We now report fine mapping of a susceptibility gene in the 11q22-24 region, determined on the basis of a University College London (UCL) sample of 496 cases and 488 supernormal controls. Confirmation was then performed by the study of an Aberdeen sample consisting of 858 cases and 591 controls (for a total of 2,433 individuals: 1,354 with schizophrenia and 1,079 controls). Seven microsatellite or single-nucleotide polymorphism (SNP) markers localized within or near the FXYD6 gene showed empirically significant allelic associations with schizophrenia in the UCL sample (for D11S1998, P=.021; for rs3168238, P=.009; for TTTC20.2, P=.048; for rs1815774, P=.049; for rs4938445, P=.010; for rs4938446, P=.025; for rs497768, P=.023). Several haplotypes were also found to be associated with schizophrenia; for example, haplotype Hap-F21 comprising markers rs10790212-rs4938445-rs497768 was found to be associated with schizophrenia, by a global permutation test (P=.002). Positive markers in the UCL sample were then genotyped in the Aberdeen sample. Two of these SNPs were found to be associated with schizophrenia in the Scottish sample (for rs4938445, P=.044; for rs497768, P=.037). The Hap-F21 haplotype also showed significant association with schizophrenia in the Aberdeen sample, with the same alleles being associated (P=.013). The FXYD6 gene encodes a protein called "phosphohippolin" that is highly expressed in regions of the brain thought to be involved in schizophrenia. The protein functions by modulating the kinetic properties of Na,K-ATPase to the specific physiological requirements of the tissue. Etiological base-pair changes in FXYD6 or in associated promoter/control regions are likely to cause abnormal function or expression of phosphohippolin and to increase genetic susceptibility to schizophrenia.
authors.affiliation: Molecular Psychiatry Laboratory, Department of Mental Health Sciences, University College London Medical School, Windeyer Institute of Medical Sciences, London, W1T 4JF, UK.
authors.forename: Khalid
authors.initials: K
authors.lastname: Choudhury
authors.forename: Andrew
authors.initials: A
authors.lastname: McQuillin
authors.forename: Vinay
authors.initials: V
authors.lastname: Puri
authors.forename: Jonathan
authors.initials: J
authors.lastname: Pimm
authors.forename: Susmita
authors.initials: S
authors.lastname: Datta
authors.forename: Srinivasa
authors.initials: S
authors.lastname: Thirumalai
authors.forename: Robert
authors.initials: R
authors.lastname: Krasucki
authors.forename: Jacob
authors.initials: J
authors.lastname: Lawrence
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Bass
authors.forename: Digby
authors.initials: D
authors.lastname: Quested
authors.forename: Caroline
authors.initials: C
authors.lastname: Crombie
authors.forename: Gillian
authors.initials: G
authors.lastname: Fraser
authors.forename: Nicholas
authors.initials: N
authors.lastname: Walker
authors.forename: Haitham
authors.initials: H
authors.lastname: Nadeem
authors.forename: Sophie
authors.initials: S
authors.lastname: Johnson
authors.forename: David
authors.initials: D
authors.lastname: Curtis
authors.forename: David
authors.initials: D
authors.lastname: St Clair
authors.forename: Hugh M D
authors.initials: HM
authors.lastname: Gurling
mesh_terms: D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007473:Ion Channels / Q000235:genetics*; D015810:Linkage Disequilibrium; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012559:Schizophrenia / Q000235:genetics*; D006113:United Kingdom
chemical_list: D007473:Ion Channels; C425298:phosphohippolin