title: Genetic association suggests that SMOC1 mediates between prenatal sex hormones and digit ratio.
abstract: Men and women differ statistically in the relative lengths of their index and ring fingers; and the ratio of these lengths has been used as a biomarker for prenatal testosterone. The ratio has been correlated with a wide range of traits and conditions including prostate cancer, obesity, autism, ADHD, and sexual orientation. In a genome-wide association study of 979 healthy adults, we find that digit ratio is strongly associated with variation upstream of SMOC1 (rs4902759: P = 1.41 × 10(-8)) and a meta-analysis of this and an independent study shows a probability of P = 1.5 × 10(-11). The protein encoded by SMOC1 has recently been shown to play a critical role in limb development; its expression in prostate tissue is dependent on sex hormones, and it has been implicated in the sexually dimorphic development of the gonads. We put forward the hypothesis that SMOC1 provides a link between prenatal hormone exposure and digit ratio.
authors.affiliation: Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK. ajl69@cam.ac.uk
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Lawrance-Owen
authors.forename: Gary
authors.initials: G
authors.lastname: Bargary
authors.forename: Jenny M
authors.initials: JM
authors.lastname: Bosten
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Goodbourn
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Hogg
authors.forename: J D
authors.initials: JD
authors.lastname: Mollon
mesh_terms: D000328:Adult; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics; D055106:Genome-Wide Association Study; D012739:Gonadal Steroid Hormones / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D015676:Osteonectin / Q000096:biosynthesis / Q000235:genetics*; D011467:Prostate / Q000378:metabolism
chemical_list: D012739:Gonadal Steroid Hormones; D015676:Osteonectin; C468135:SMOC1 protein, human