COGNITIVE NEUROSCIENCEPolymorphisms of genes controlling homocysteine/folate metabolism and cognitive functionBarbaux, Sandrine1; Plomin, Robert2; Whitehead, Alexander S.1,3Author Information 1Department of Pharmacology and Center for Pharmacogenetics, 153 Johnson Pavilion, University of Pennsylvania School of Medicine, Philadelphia, PA 19104–6084, USA 2Social, Genetic and Developmental Psychiatry Research Centre, Institute of Psychiatry, London, UK 3Corresponding Author: Alexander S. Whitehead Acknowledgements: The IQ QTL Project, supported by the National Institute of Child Health and Human Development (HD27694), is a collaborative project including the Department of Psychological Medicine, University of Wales, College of Medicine, Cardiff (Michael J. Owen), the Department of Microbiology and Immunology, Milton S. Hershey Medical Center, Pennsylvania State University (Michael J. Chorney) and the Institute of Psychiatry, King's College, London (Robert Plomin). Received 18 January 2000; accepted 30 January 2000 NeuroReport: April 7, 2000 - Volume 11 - Issue 5 - p 1133-1136 Buy Abstract Elevated concentrations of the amino acid homocysteine and/or folate deficiency have been reported to affect neural development/function in both human patients and animal models. We have investigated the distribution of functional polymorphisms in genes involved in homocysteine/folate metabolism in children with high IQ and in children with average IQ. No differences in the frequencies of genetic variants in the methionine synthase or methylenetetrahydrofolate reductase genes were found. However, the cystathionine β-synthase (CBS) 844ins68 allele was significantly underrepresented in children with high IQ. The mechanism by which a functional genetic variant in the CBS gene may influence cognitive function remains to be determined. © 2000 Lippincott Williams & Wilkins, Inc.