title: Handedness and the X chromosome: the role of androgen receptor CAG-repeat length.
abstract: Prenatal androgen exposure has been suggested to be one of the factors influencing handedness, making the androgen receptor gene (AR) a likely candidate gene for individual differences in handedness. Here, we examined the relationship between the length of the CAG-repeat in AR and different handedness phenotypes in a sample of healthy adults of both sexes (n = 1057). Since AR is located on the X chromosome, statistical analyses in women heterozygous for CAG-repeat lengths are complicated by X chromosome inactivation. We thus analyzed a sample of women that were homozygous for the CAG-repeat length (n = 77). Mixed-handedness in men was significantly associated with longer CAG-repeat blocks and women homozygous for longer CAG-repeats showed a tendency for stronger left-handedness. These results suggest that handedness in both sexes is associated with the AR CAG-repeat length, with longer repeats being related to a higher incidence of non-right-handedness. Since longer CAG-repeat blocks have been linked to less efficient AR function, these results implicate that differences in AR signaling in the developing brain might be one of the factors that determine individual differences in brain lateralization.
authors: Department of Human Genetics, Ruhr-University, 44780 Bochum, Germany.
authors: Larissa
authors: L
authors: Arning
authors: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University, 44780 Bochum, Germany.
authors: Sebastian
authors: S
authors: Ocklenburg
authors: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University, 44780 Bochum, Germany.
authors: Stefanie
authors: S
authors: Schulz
authors: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University, 44780 Bochum, Germany.
authors: Vanessa
authors: V
authors: Ness
authors: Department of Human Genetics, Ruhr-University, 44780 Bochum, Germany.
authors: Wanda M
authors: WM
authors: Gerding
authors: Leibniz Research Centre for Working Environment and Human Factors (IfADo), 44139 Dortmund, Germany.
authors: Jan G
authors: JG
authors: Hengstler
authors: Leibniz Research Centre for Working Environment and Human Factors (IfADo), 44139 Dortmund, Germany.
authors: Michael
authors: M
authors: Falkenstein
authors: Department of Human Genetics, Ruhr-University, 44780 Bochum, Germany.
authors: Jörg T
authors: JT
authors: Epplen
authors: Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University, 44780 Bochum, Germany.
authors: Onur
authors: O
authors: Güntürkün
authors: Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, 01309 Dresden, Germany.
authors: Christian
authors: C
authors: Beste
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D041321:Chromosomes, Human, X; D005260:Female; D007839:Functional Laterality / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011944:Receptors, Androgen / Q000235:genetics; D012737:Sex Factors; D018911:Trinucleotide Repeats; D055815:Young Adult
chemical_list: D011944:Receptors, Androgen