title: Hypnotizability and Catechol-O-Methyltransferase (COMT) polymorphysms in Italians.
abstract: Higher brain dopamine content depending on lower activity of Catechol-O-Methyltransferase (COMT) in subjects with high hypnotizability scores (highs) has been considered responsible for their attentional characteristics. However, the results of the previous genetic studies on association between hypnotizability and the COMT single nucleotide polymorphism (SNP) rs4680 (Val(158)Met) were inconsistent. Here, we used a selective genotyping approach to re-evaluate the association between hypnotizability and COMT in the context of a two-SNP haplotype analysis, considering not only the Val(158)Met polymorphism, but also the closely located rs4818 SNP. An Italian sample of 53 highs, 49 low hypnotizable subjects (lows), and 57 controls, were genotyped for a segment of 805 bp of the COMT gene, including Val(158)Met and the closely located rs4818 SNP. Our selective genotyping approach had 97.1% power to detect the previously reported strongest association at the significance level of 5%. We found no evidence of association at the SNP, haplotype, and diplotype levels. Thus, our results challenge the dopamine-based theory of hypnosis and indirectly support recent neuropsychological and neurophysiological findings reporting the lack of any association between hypnotizability and focused attention abilities.
authors.affiliation: Laboratory of Cognitive and Behavioral Neurosciences, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy.
authors.forename: Silvano
authors.initials: S
authors.lastname: Presciuttini
authors.affiliation: Laboratory of Cognitive and Behavioral Neurosciences, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy ; Language and Genetics Department, Max Planck Institute for Psycholinguistics Nijmegen, Netherlands.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gialluisi
authors.affiliation: Immunohematology Unit, Azienda Ospedaliera-Universitaria Pisana Pisa, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Barbuti
authors.affiliation: Immunohematology Unit, Azienda Ospedaliera-Universitaria Pisana Pisa, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Curcio
authors.affiliation: Immunohematology Unit, Azienda Ospedaliera-Universitaria Pisana Pisa, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Scatena
authors.affiliation: Laboratory of Cognitive and Behavioral Neurosciences, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy ; Department of Medicine, Surgery and Neuroscience, University of Siena Siena, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Carli
authors.affiliation: Laboratory of Cognitive and Behavioral Neurosciences, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy.
authors.forename: Enrica L
authors.initials: EL
authors.lastname: Santarcangelo
keywords: COMT; absorption; attention; haplotype analysis; hypnotizability; selective genotyping