title: Investigation of the DCDC2 intron 2 deletion/compound short tandem repeat polymorphism in a large German dyslexia sample.
abstract: Dyslexia is a complex disorder manifested by difficulties in learning to read and spell despite conventional instruction, adequate intelligence and sociocultural opportunity. It is among the most common neurodevelopmental disorders with a prevalence of 5-12%. The dyslexia susceptibility locus 2 on chromosome 6p21-p22 is one of the best-replicated linkage regions in dyslexia. On the basis of systematic linkage disequilibrium studies, the doublecortin domain containing protein 2 gene (DCDC2) was identified as a strong candidate gene in this region. Data from a US study have suggested a complex deletion/compound short tandem repeat (STR) polymorphism in intron 2 of DCDC2 as the causative mutation. In this study, we analyzed this polymorphism in 396 German dyslexia trios which included 376 trios previously providing strong support for the DCDC2 locus. We observed no significant deviation from random transmission, neither for the deletion nor for the alleles of the compound STR. We also did not find the deletion or any of the STR alleles to be in linkage disequilibrium with the 2-marker haplotype, which was associated with dyslexia in our sample. We thus conclude that the causative variant/s in DCDC2 conferring susceptibility to dyslexia in our sample remain/s to be identified.
authors.affiliation: Department of Genomics, Life and Brain Center, University of Bonn, Bonn, Germany.
authors.forename: Kerstin U
authors.initials: KU
authors.lastname: Ludwig
authors.forename: Johannes
authors.initials: J
authors.lastname: Schumacher
authors.forename: Gerd
authors.initials: G
authors.lastname: Schulte-Körne
authors.forename: Inke R
authors.initials: IR
authors.lastname: König
authors.forename: Andreas
authors.initials: A
authors.lastname: Warnke
authors.forename: Ellen
authors.initials: E
authors.lastname: Plume
authors.forename: Heidi
authors.initials: H
authors.lastname: Anthoni
authors.forename: Myriam
authors.initials: M
authors.lastname: Peyrard-Janvid
authors.forename: Haiying
authors.initials: H
authors.lastname: Meng
authors.forename: Andreas
authors.initials: A
authors.lastname: Ziegler
authors.forename: Helmut
authors.initials: H
authors.lastname: Remschmidt
authors.forename: Juha
authors.initials: J
authors.lastname: Kere
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Gruen
authors.forename: Bertram
authors.initials: B
authors.lastname: Müller-Myhsok
authors.forename: Markus M
authors.initials: MM
authors.lastname: Nöthen
authors.forename: Per
authors.initials: P
authors.lastname: Hoffmann
mesh_terms: D002896:Chromosomes, Human, Pair 6; D004410:Dyslexia / Q000235:genetics*; D017353:Gene Deletion; D005858:Germany; D006801:Humans; D007438:Introns; D015810:Linkage Disequilibrium; D018895:Microsatellite Repeats; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: C510451:DCDC2 protein, human; D008869:Microtubule-Associated Proteins