Array comparative genomic hybridization characterization of prenatally detected de novo apparently balanced reciprocal translocations with or without genomic imbalance in other chromosomes
JOURNAL OF THE CHINESE MEDICAL ASSOCIATION
Authors: Chen, Chih-Ping; Chen, Ming; Ma, Gwo-Chin; Su, Yi-Ning; Ko, Tsang-Ming; Lin, Yi-Hui; Wang, Wayseen
Abstract
We present our experience of array comparative genomic hybridization (aCGH) characterization of two cases of prenatally detected de novo simple and complex apparently balanced reciprocal translocations. Amniocentesis of the first case revealed a complex chromosome rearrangement and a karyotype of 46,XY,t(5;8;6)(q11.2;p23.1;q22.32)dn. aCGH of amniocytes revealed no genomic imbalance. Ultrasound findings were unremarkable. The pregnancy was carried to term, and pediatric follow-ups were normal at 3 months of age. Amniocentesis of the second case revealed a simple reciprocal translocation and a karyotype of 46,XY,t(3;11)(q14;q23)dn. aCGH of amniocytes revealed a 1.32-Mb microduplication in chromosome 2p12 [arr cgh 2p12 (75,245,747-76,563,965)x3] encompassing the genes of TACR1, FAM176A, MRPL19, and C2orf3. Ultrasound findings were unremarkable. The pregnancy was carried to term, and the pediatric follow-ups were normal at 8 months of age. In cases of prenatally detected de novo apparently balanced reciprocal translocations, cryptic intrachromosomal rearrangements may exist in addition to the cytogenetically visible structural chromosome aberrations. aCGH is useful not only in identifying the genomic imbalances at the breakpoints, but also in detecting unexpectedly complex rearrangements in other chromosomes. Copyright (C) 2012 Elsevier Taiwan LLC and the Chinese Medical Association. All rights reserved.
Genetic analysis of dyslexia candidate genes in the European cross-linguistic NeuroDys cohort
EUROPEAN JOURNAL OF HUMAN GENETICS
Authors: Becker, Jessica; Czamara, Darina; Scerri, Tom S.; Ramus, Franck; Csepe, Valeria; Talcott, Joel B.; Stein, John; Morris, Andrew; Ludwig, Kerstin U.; Hoffmann, Per; Honbolygo, Ferenc; Toth, Denes; Fauchereau, Fabien; Bogliotti, Caroline; Iannuzzi, Stephanie; Chaix, Yves; Valdois, Sylviane; Billard, Catherine; George, Florence; Soares-Boucaud, Isabelle; Gerard, Christophe-Loic; van der Mark, Sanne; Schulz, Enrico; Vaessen, Anniek; Maurer, Urs; Lohvansuu, Kaisa; Lyytinen, Heikki; Zucchelli, Marco; Brandeis, Daniel; Blomertw, Leo; Leppanen, Paavo H. T.; Bruder, Jennifer; Monaco, Anthony P.; Mueller-Myhsok, Bertram; Kere, Juha; Landerl, Karin; Noethen, Markus M.; Schulte-Koerne, Gerd; Paracchini, Silvia; Peyrard-Janvid, Myriam; Schumacher, Johannes
Abstract
Dyslexia is one of the most common childhood disorders with a prevalence of around 5-10% in school-age children. Although an important genetic component is known to have a role in the aetiology of dyslexia, we are far from understanding the molecular mechanisms leading to the disorder. Several candidate genes have been implicated in dyslexia, including DYX1C1, DCDC2, KIAA0319, and the MRPL19/C2ORF3 locus, each with reports of both positive and no replications. We generated a European cross-linguistic sample of school-age children - the NeuroDys cohort - that includes more than 900 individuals with dyslexia, sampled with homogenous inclusion criteria across eight European countries, and a comparable number of controls. Here, we describe association analysis of the dyslexia candidate genes/locus in the NeuroDys cohort. We performed both case-control and quantitative association analyses of single markers and haplotypes previously reported to be dyslexia-associated. Although we observed association signals in samples from single countries, we did not find any marker or haplotype that was significantly associated with either case-control status or quantitative measurements of word-reading or spelling in the meta-analysis of all eight countries combined. Like in other neurocognitive disorders, our findings underline the need for larger sample sizes to validate possibly weak genetic effects. published online 11 September 2013