1. ¹Department of Psychology, University of Edinburgh, Edinburgh, UK
2. ²Genetic Epidemiology Laboratory, Queensland Institute of Medical Research, Brisbane, Australia
3. ³Department of Psychology, University of Melbourne, Melbourne, Australia
4. ⁴Macquarie Centre for Cognitive Science, Macquarie University, Sydney, Australia

Correspondence: Dr TC Bates, Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK. Tel: +44 131 651 1945; Fax: +44 131 650 3461; E-mail: tim.bates@ed.ac.uk

Received 27 December 2005; Revised 9 October 2006; Accepted 10 October 2006; Published online 22 November 2006.

Abstract

We report the first genome-wide linkage analysis for reading and spelling in a sample of 403 families of twins, aged between 12 and 25 years taken from the normal population and unselected for reading ability. These traits showed heritabilities of 0.52–0.73, and support for linkage exceeded replication levels (lod>1.44) of seven of the 11 linkages reported in dyslexic samples, namely: 2q22.3, 3p12-q13, 6q11.2, 7q32, 15q21.1, 18p21, and Xq27.3. For five of these (2q22.3, 6q11.2, 7q32, 18p21, and Xq27), this study provides the first independent replication. 1p34–36 and 2p15–16 received some support, with lods of 1.2 and 0.83, respectively, whereas two regions received little support (6p23–21.3 and 11p15.5). This study also identified two novel linkages at 4p15.33-16.1 and 17p13.3, which received suggestive support (max. lod 2.08 and 1.99, respectively).