title: A susceptibility gene for psoriatic arthritis maps to chromosome 16q: evidence for imprinting.
abstract: Several genetic loci have been reported for psoriasis, but none has been specifically linked to psoriatic arthritis (PsA), a condition that affects >10% of patients with psoriasis. A genetic component for PsA is suggested by segregation within families and high concordance among identical twins. We performed a linkage scan to map genes contributing to PsA. We identified 178 patients with PsA out of 906 patients who were included in our genetic study of psoriasis. Using a comprehensive genealogy database, we were able to connect 100 of these into 39 families. We genotyped the patients using a framework marker set of 1,000 microsatellite markers, with an average density of 3 cM, and performed multipoint, affected-only, allele-sharing linkage analysis using the Allegro program. On the basis of the initial results, we genotyped more markers for the most prominent loci. A linkage with a LOD score of 2.17 was observed on chromosome 16q. The linkage analysis, conditioned on paternal transmission to affected individuals, gave a LOD score of 4.19, whereas a LOD score of only 1.03 was observed when conditioned for maternal transmission. A suggestive locus on chromosome 16q has previously been implicated in psoriasis. Our data indicate that a gene at this locus may be involved in paternal transmission of PsA.
authors.affiliation: deCODE Genetics, Reykjavik, Iceland. akarason@decode.is
authors.forename: Ari
authors.initials: A
authors.lastname: Karason
authors.forename: Johann E
authors.initials: JE
authors.lastname: Gudjonsson
authors.forename: Ruchi
authors.initials: R
authors.lastname: Upmanyu
authors.forename: Arna A
authors.initials: AA
authors.lastname: Antonsdottir
authors.forename: Valdimar B
authors.initials: VB
authors.lastname: Hauksson
authors.forename: E Hjaltey
authors.initials: EH
authors.lastname: Runasdottir
authors.forename: Hjortur H
authors.initials: HH
authors.lastname: Jonsson
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Gudbjartsson
authors.forename: Michael L
authors.initials: ML
authors.lastname: Frigge
authors.forename: Augustine
authors.initials: A
authors.lastname: Kong
authors.forename: Kari
authors.initials: K
authors.lastname: Stefansson
authors.forename: Helgi
authors.initials: H
authors.lastname: Valdimarsson
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Gulcher
mesh_terms: D000483:Alleles; D015535:Arthritis, Psoriatic / Q000235:genetics*; D002874:Chromosome Mapping; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D018392:Genomic Imprinting / Q000235:genetics*; D006801:Humans; D008126:Lod Score; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics