Hoekstra, Rosa A.; Bartels, Meike and Boomsma, Dorret I.
|DOI (Digital Object Identifier) Link:||http://dx.doi.org/doi:10.1375/twin.9.4.558|
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The aim of this study was to estimate the heritability of variation in testosterone levels in 12-year-old children, and to explore the overlap in genetic and environmental influences on circulating testosterone levels and androgen-dependent pubertal development. Midday salivary testosterone samples were collected on 2 consecutive days in a sample of 183 unselected twin pairs. Androgen-induced pubertal development was assessed using self-report Tanner scales of pubic hair development (boys and girls) and genital development (boys). A significant contribution of genetic effects to the variance in testosterone levels was found. Heritability was approximately 50% in both boys and girls. The remaining proportion of the variance in testosterone levels could be explained by nonshared environmental influences. The relatively high correlation between testosterone levels of opposite-sex dizygotic twins suggests that sex differences in genes influencing variation in testosterone levels have not yet developed in preand early puberty. Variance in pubertal development was explained by a large genetic component, moderate shared environmental influences, and a small nonshared environmental effect. Testosterone levels correlated moderately (r = .31) with pubertal development; the covariance between testosterone levels and pubertal development was entirely accounted for by genetic influences.
|Item Type:||Conference Item|
|Copyright Holders:||2005 Not known|
|Extra Information:||Twin Research and Human Genetics, Volume 9, Number 4, August 2006 , pp. 558-565(8)
|Academic Unit/Department:||Science > Life, Health and Chemical Sciences|
|Depositing User:||Rosa Hoekstra|
|Date Deposited:||11 Apr 2011 10:07|
|Last Modified:||11 Apr 2011 10:07|
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