Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Neuropsychobiology 2007;56:208–212 DOI: 10.1159/000122266 Temperamental Activity and Epidermal Growth Factor A61G Polymorphism in Finnish Adults Sampsa Puttonen a, c Liisa Keltikangas-Järvinen a Marko Elovainio b Mika Kivimäki e Riikka Rontu d Terho Lehtimäki d a Department of Psychology, University of Helsinki, b National Research and Development Centre for Welfare and Health, c Finnish Institute of Occupational Health, Helsinki, d Department of Clinical Chemistry, Laboratory of Atherosclerosis Genetics, Tampere University Hospital and University of Tampere Medical School, Tampere, Finland; e Department of Epidemiology and Public Health, University College London, London, UK Introduction According to the approach to temperament by Buss and Plomin [1, 2], people vary in 3 broad dimensions. Emotionality refers to experiencing and showing fre- quent and intense negative emotions. Sociability reflects the tendency of preferring the presence of others to being alone. Activity refers to the spontaneous pace of action and amplitude of motor responses. Previous research has shown that especially temperamental activity correlates with physiological factors, such as the metabolic syn- drome [3, 4]. Quantitative genetic studies indicate that temperamental activity is to a large degree heritable [1]. Yet, specific genes influencing individual differences in temperamental activity have not been identified. Epidermal growth factor (EGF) protein has wide- spread effects on the developing and mature nervous sys- tem, including central nervous system growth, differen- tiation and maintenance. Lazar and Blum [5] showed that in mouse brain, EGF production begins as early as em- bryonic day 14 and that EGF is postnatally widely distrib- uted in the brain, including the brainstem, cerebral cor- tex, hippocampus, basal hypothalamus, striatum and thalamus. It stimulates the proliferation of ectodermal Key Words Epidermal growth factor  Genotype  Activity temperament Abstract Background/Aims: Epidermal growth factor (EGF) has wide- spread effects on the developing and mature nervous sys- tem. This study examined whether genetic differences in the EGF predict differences in the self-reported level of activity temperament in adults. Methods: Two hundred and nine- ty-two men and women from the population-based Cardio- vascular Risk in Young Finns Study were genotyped for the functional EGF gene A61G polymorphisms, and their tem- peramental activity was assessed 3 times in 1992, 1997 and 2001. Results: The EGF gene predicted temperamental ac- tivity (the mean of 3 assessments, p = 0.007), with the G/G genotype being associated with the highest level of activity. Additional analyses in separate years indicated that the as- sociation was robust across different measurements of activ- ity (p ^ 0.05 in 1992 and 1997, p = 0.008 in 2001). Conclusion: These results suggest that polymorphic variation in the EGF A61 gene may be one of the factors underlying the temper- ament dimension of activity. Copyright © 2008 S. Karger AG, Basel Received: December 7, 2007 Accepted: January 22, 2008 Published online: April 2, 2008 L. Keltikangas-Järvinen Department of Psychology, University of Helsinki PO Box 9, FI–00014 Helsinki (Finland) Tel. +358 9 1912 9500, Fax +358 9 1912 9521 E-Mail liisa.keltikangas-jarvinen@helsinki.fi © 2008 S. Karger AG, Basel 0302–282X/07/0564–0208$23.50/0 Accessible online at: www.karger.com/nps Downloaded by: University of Tampere 153.1.44.164 - 5/24/2016 10:42:55 AM