1. ¹Department of Psychology, MRC Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK
2. ²Genetic Epidemiology, Queensland Institute of Medical Research, Brisbane, Queensland, Australia
3. ³School of Medicine, The University of Manchester, Manchester, UK
4. ⁴Biological Psychology, Vrije Universiteit of Amsterdam, Amsterdam, The Netherlands
5. ⁵King's College London, Institute of Psychiatry, London, UK
6. ⁶Mental Health, University of Aberdeen, Aberdeen, UK

Correspondence: Dr M Luciano, Department of Psychology, MRC Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh, Lothian EH8 9JZ, UK. Tel: +44 131 651 5040; Fax: +44 131 651 1771; E-mail: michelle.luciano@ed.ac.uk

⁷The authors wish it to be known that, in their opinion, the first 2 authors should be regarded as joint First Authors

Received 30 October 2007; Revised 11 March 2008; Accepted 17 April 2008; Published online 21 May 2008.

Abstract

A 5-single nucleotide polymorphism (SNP) set has been associated with general cognitive ability in 5000 7-year-old children from the Twins Early Development Study (TEDS). Four of these SNPs were identified through a 10 K microarray analysis and one was identified through a targeted analysis of brain-expressed genes. The present study tested this association with general cognitive ability in six population samples of varying size and age from Australia, the UK (Scotland and England) and the Netherlands. Results from the largest sample (N=1310) approached significance (P=0.06) in the direction of the original finding, but results from the other samples (N=205–758) were mixed. A meta-analysis of the results – allowing for effect size heterogeneity between samples – yielded a non-significant correlation (r=-0.01, P=0.57), indicating that this SNP set was not associated with general cognitive ability in the populations studied.