title: European combined analysis of the CTG18.1 and the ERDA1 CAG/CTG repeats in bipolar disorder.
abstract: Several groups have reported association between large CAG/CTG repeats in the genome and BP disorder using the Repeat Expansion Detection (RED) method. Molecular interpretation studies demonstrated that around 90% of the large CAG/CTG repeats detected by RED can by explained by repeat size at either the CTG18.1 or ERDA-1 locus. In this study we report the findings on a large European BP case-control sample analysed for these two frequently expanded repeats. The frequency of expanded alleles (>40 repeats) at the CTG18.1 locus was significantly higher in the subgroup of patients with a more severe phenotype BPI and a positive first degree family history than in a group of matched controls (9% vs 5%). No difference in ERDA-1 expansion frequency was seen between BP cases and matched controls. We conclude that the ERDA-1 locus is not related to the BP phenotype while expanded alleles at the CTG18.1 locus cannot be excluded as a vulnerability factor for BP disorder.
authors.affiliation: Department of Molecular Genetics, Flanders Interuniversity Institute for Biotechnology (VIB), University of Antwerp (UIA), Belgium.
authors.forename: Jurgen
authors.initials: J
authors.lastname: Del-Favero
authors.forename: Sofie Van
authors.initials: SV
authors.lastname: Gestel
authors.forename: Anders D
authors.initials: AD
authors.lastname: Børglum
authors.forename: Walter
authors.initials: W
authors.lastname: Muir
authors.forename: Henrik
authors.initials: H
authors.lastname: Ewald
authors.forename: Ole
authors.initials: O
authors.lastname: Mors
authors.forename: Sladana
authors.initials: S
authors.lastname: Ivezic
authors.forename: Lilijana
authors.initials: L
authors.lastname: Oruc
authors.forename: Rolf
authors.initials: R
authors.lastname: Adolfsson
authors.forename: Douglas
authors.initials: D
authors.lastname: Blackwood
authors.forename: Torben
authors.initials: T
authors.lastname: Kruse
authors.forename: Julien
authors.initials: J
authors.lastname: Mendlewicz
authors.forename: Martin
authors.initials: M
authors.lastname: Schalling
authors.forename: Christine
authors.initials: C
authors.lastname: Van Broeckhoven
mesh_terms: D000483:Alleles; D001714:Bipolar Disorder / Q000235:genetics*; D016022:Case-Control Studies; D005060:Europe; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*