1. ¹Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA
2. ²Department of Psychiatry, The University of Chicago, Chicago, IL 60637, USA
3. ³Department of Statistics, The University of Chicago, Chicago, IL 60637, USA
4. ⁴Roche Molecular Systems, Inc., Alameda, CA 94501, USA

Correspondence: Dr M Abney, 920 East 58th Street, Room 507E, Chicago, IL 60637, USA. Tel: +1 773 702 3388; Fax: +1 773 834 0505; E-mail: abney@uchicago.edu

⁵The first two authors contributed equally

⁶Current address: Department of Biological Sciences, Rochester Institute of Technology, Rochester 14623, NY, USA

Received 26 February 2004; Revised 28 April 2004; Accepted 5 May 2004; Published online 4 August 2004.

Abstract

Serotonin has been implicated in common disorders involving the central nervous, gastrointestinal, cardiovascular, and pulmonary systems. We describe the first genome-wide screen to identify quantitative trait loci (QTLs) influencing whole blood serotonin in 567 members of a single large pedigree, using a novel association-based mapping approach. We identified an association between the 3 integrin (ITGB3) Leu33Pro polymorphism on 17q21 and whole blood serotonin levels (P-value=9.8 10^-5). This variant explained the evidence for linkage in this region when included as a covariate in the linkage analysis (change in LOD from 1.87 to 0.16), indicating that ITGB3 may be an important serotonin QTL.